Upgrade fbjni

Summary:
Upgrades Yoga’s copy of *fbjni* to the latest version.

This will enable us

- to move from `finalize()` to `PhantomReference` to deallocate native memory, with the potential of making GC more efficient.
- to remove the internal dependency to *libfb,* allowing apps without an own dependency to ship less code

Reviewed By: passy

Differential Revision: D16220924

fbshipit-source-id: e8233fe2b5403946ff51f43cb6def558ded52fda

java/jni/YGJNI.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
-#include <fb/fbjni.h>
+#include <fbjni/fbjni.h>
 #include <yoga/YGNode.h>
 #include <yoga/Yoga.h>
 #include <yoga/Yoga-internal.h>

java/jni/YGJTypes.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
-#include <fb/fbjni.h>
+#include <fbjni/fbjni.h>
 #include <yoga/YGValue.h>
 #include <yoga/Yoga.h>
 #include <map>

lib/fb/BUCK

@@ -32,6 +32,7 @@ yoga_cxx_library(
         "-Wall",
         "-Werror",
         "-Wno-unused-parameter",
+        "-Wno-unused-variable",
         "-std=c++11",
     ],
     platforms = (ANDROID,),

lib/fb/src/main/cpp/assert.cpp

@@ -1,38 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include <cstdarg>
-#include <stdio.h>
-
-#include <fb/assert.h>
-#include <fb/log.h>
-
-namespace facebook {
-
-#define ASSERT_BUF_SIZE 4096
-static char sAssertBuf[ASSERT_BUF_SIZE];
-static AssertHandler gAssertHandler;
-
-void assertInternal(const char* formatstr ...) {
-    va_list va_args;
-    va_start(va_args, formatstr);
-    vsnprintf(sAssertBuf, sizeof(sAssertBuf), formatstr, va_args);
-    va_end(va_args);
-    if (gAssertHandler != NULL) {
-        gAssertHandler(sAssertBuf);
-    }
-    FBLOG(LOG_FATAL, "fbassert", "%s", sAssertBuf);
-    // crash at this specific address so that we can find our crashes easier
-    *(int*)0xdeadb00c = 0;
-    // let the compiler know we won't reach the end of the function
-     __builtin_unreachable();
-}
-
-void setAssertHandler(AssertHandler assertHandler) {
-    gAssertHandler = assertHandler;
-}
-
-} // namespace facebook

lib/fb/src/main/cpp/include/fb/ALog.h

@@ -1,80 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-/** @file ALog.h
- *
- *  Very simple android only logging. Define LOG_TAG to enable the macros.
- */
-
-#pragma once
-
-#ifdef __ANDROID__
-
-#include <android/log.h>
-
-namespace facebook {
-namespace alog {
-
-template<typename... ARGS>
-inline void log(int level, const char* tag, const char* msg, ARGS... args) noexcept {
-  __android_log_print(level, tag, msg, args...);
-}
-
-template<typename... ARGS>
-inline void log(int level, const char* tag, const char* msg) noexcept {
-  __android_log_write(level, tag, msg);
-}
-
-template<typename... ARGS>
-inline void logv(const char* tag, const char* msg, ARGS... args) noexcept {
-  log(ANDROID_LOG_VERBOSE, tag, msg, args...);
-}
-
-template<typename... ARGS>
-inline void logd(const char* tag, const char* msg, ARGS... args) noexcept {
-  log(ANDROID_LOG_DEBUG, tag, msg, args...);
-}
-
-template<typename... ARGS>
-inline void logi(const char* tag, const char* msg, ARGS... args) noexcept {
-  log(ANDROID_LOG_INFO, tag, msg, args...);
-}
-
-template<typename... ARGS>
-inline void logw(const char* tag, const char* msg, ARGS... args) noexcept {
-  log(ANDROID_LOG_WARN, tag, msg, args...);
-}
-
-template<typename... ARGS>
-inline void loge(const char* tag, const char* msg, ARGS... args) noexcept {
-  log(ANDROID_LOG_ERROR, tag, msg, args...);
-}
-
-template<typename... ARGS>
-inline void logf(const char* tag, const char* msg, ARGS... args) noexcept {
-  log(ANDROID_LOG_FATAL, tag, msg, args...);
-}
-
-
-#ifdef LOG_TAG
-# define ALOGV(...) ::facebook::alog::logv(LOG_TAG, __VA_ARGS__)
-# define ALOGD(...) ::facebook::alog::logd(LOG_TAG, __VA_ARGS__)
-# define ALOGI(...) ::facebook::alog::logi(LOG_TAG, __VA_ARGS__)
-# define ALOGW(...) ::facebook::alog::logw(LOG_TAG, __VA_ARGS__)
-# define ALOGE(...) ::facebook::alog::loge(LOG_TAG, __VA_ARGS__)
-# define ALOGF(...) ::facebook::alog::logf(LOG_TAG, __VA_ARGS__)
-#endif
-
-}}
-
-#else
-# define ALOGV(...) ((void)0)
-# define ALOGD(...) ((void)0)
-# define ALOGI(...) ((void)0)
-# define ALOGW(...) ((void)0)
-# define ALOGE(...) ((void)0)
-# define ALOGF(...) ((void)0)
-#endif

lib/fb/src/main/cpp/include/fb/Countable.h

@@ -1,44 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-#include <atomic>
-#include <fb/assert.h>
-#include <fb/noncopyable.h>
-#include <fb/nonmovable.h>
-#include <fb/RefPtr.h>
-
-namespace facebook {
-
-class Countable : public noncopyable, public nonmovable {
-public:
-  // RefPtr expects refcount to start at 0
-  Countable() : m_refcount(0) {}
-  virtual ~Countable()
-  {
-    FBASSERT(m_refcount == 0);
-  }
-
-private:
-  void ref() {
-    ++m_refcount;
-  }
-
-  void unref() {
-    if (0 == --m_refcount) {
-      delete this;
-    }
-  }
-
-  bool hasOnlyOneRef() const {
-    return m_refcount == 1;
-  }
-
-  template <typename T> friend class RefPtr;
-  std::atomic<int> m_refcount;
-};
-
-}

lib/fb/src/main/cpp/include/fb/ProgramLocation.h

@@ -1,47 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-#include <cstring>
-#include <string>
-#include <sstream>
-
-namespace facebook {
-
-#define FROM_HERE facebook::ProgramLocation(__FUNCTION__, __FILE__, __LINE__)
-
-class ProgramLocation {
-public:
-  ProgramLocation() : m_functionName("Unspecified"), m_fileName("Unspecified"), m_lineNumber(0) {}
-
-  ProgramLocation(const char* functionName, const char* fileName, int line) :
-      m_functionName(functionName),
-      m_fileName(fileName),
-      m_lineNumber(line)
-    {}
-
-  const char* functionName() const { return m_functionName; }
-  const char* fileName() const { return m_fileName; }
-  int lineNumber() const { return m_lineNumber; }
-
-  std::string asFormattedString() const {
-    std::stringstream str;
-    str << "Function " << m_functionName << " in file " << m_fileName << ":" << m_lineNumber;
-    return str.str();
-  }
-
-  bool operator==(const ProgramLocation& other) const {
-    // Assumes that the strings are static
-    return (m_functionName == other.m_functionName) && (m_fileName == other.m_fileName) && m_lineNumber == other.m_lineNumber;
-  }
-
-private:
-  const char* m_functionName;
-  const char* m_fileName;
-  int m_lineNumber;
-};
-
-}

lib/fb/src/main/cpp/include/fb/RefPtr.h

@@ -1,271 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-#include <utility>
-#include <fb/assert.h>
-
-namespace facebook {
-
-// Reference counting smart pointer. This is designed to work with the
-// Countable class or other implementations in the future. It is designed in a
-// way to be both efficient and difficult to misuse. Typical usage is very
-// simple once you learn the patterns (and the compiler will help!):
-//
-// By default, the internal pointer is null.
-//   RefPtr<Foo> ref;
-//
-// Object creation requires explicit construction:
-//   RefPtr<Foo> ref = createNew<Foo>(...);
-//
-// Or if the constructor is not public:
-//   RefPtr<Foo> ref = adoptRef(new Foo(...));
-//
-// But you can implicitly create from nullptr:
-//   RefPtr<Foo> maybeRef = cond ? ref : nullptr;
-//
-// Move/Copy Construction/Assignment are straightforward:
-//   RefPtr<Foo> ref2 = ref;
-//   ref = std::move(ref2);
-//
-// Destruction automatically drops the RefPtr's reference as expected.
-//
-// Upcasting is implicit but downcasting requires an explicit cast:
-//   struct Bar : public Foo {};
-//   RefPtr<Bar> barRef = static_cast<RefPtr<Bar>>(ref);
-//   ref = barRef;
-//
-template <class T>
-class RefPtr {
-public:
-  constexpr RefPtr() :
-    m_ptr(nullptr)
-  {}
-
-  // Allow implicit construction from a pointer only from nullptr
-  constexpr RefPtr(std::nullptr_t ptr) :
-    m_ptr(nullptr)
-  {}
-
-  RefPtr(const RefPtr<T>& ref) :
-    m_ptr(ref.m_ptr)
-  {
-    refIfNecessary(m_ptr);
-  }
-
-  // Only allow implicit upcasts. A downcast will result in a compile error
-  // unless you use static_cast (which will end up invoking the explicit
-  // operator below).
-  template <typename U>
-  RefPtr(const RefPtr<U>& ref, typename std::enable_if<std::is_base_of<T,U>::value, U>::type* = nullptr) :
-    m_ptr(ref.get())
-  {
-    refIfNecessary(m_ptr);
-  }
-
-  RefPtr(RefPtr<T>&& ref) :
-    m_ptr(nullptr)
-  {
-    *this = std::move(ref);
-  }
-
-  // Only allow implicit upcasts. A downcast will result in a compile error
-  // unless you use static_cast (which will end up invoking the explicit
-  // operator below).
-  template <typename U>
-  RefPtr(RefPtr<U>&& ref, typename std::enable_if<std::is_base_of<T,U>::value, U>::type* = nullptr) :
-    m_ptr(nullptr)
-  {
-    *this = std::move(ref);
-  }
-
-  ~RefPtr() {
-    unrefIfNecessary(m_ptr);
-    m_ptr = nullptr;
-  }
-
-  RefPtr<T>& operator=(const RefPtr<T>& ref) {
-    if (m_ptr != ref.m_ptr) {
-      unrefIfNecessary(m_ptr);
-      m_ptr = ref.m_ptr;
-      refIfNecessary(m_ptr);
-    }
-    return *this;
-  }
-
-  // The STL assumes rvalue references are unique and for simplicity's sake, we
-  // make the same assumption here, that &ref != this.
-  RefPtr<T>& operator=(RefPtr<T>&& ref) {
-    unrefIfNecessary(m_ptr);
-    m_ptr = ref.m_ptr;
-    ref.m_ptr = nullptr;
-    return *this;
-  }
-
-  template <typename U>
-  RefPtr<T>& operator=(RefPtr<U>&& ref) {
-    unrefIfNecessary(m_ptr);
-    m_ptr = ref.m_ptr;
-    ref.m_ptr = nullptr;
-    return *this;
-  }
-
-  void reset() {
-    unrefIfNecessary(m_ptr);
-    m_ptr = nullptr;
-  }
-
-  T* get() const {
-    return m_ptr;
-  }
-
-  T* operator->() const {
-    return m_ptr;
-  }
-
-  T& operator*() const {
-    return *m_ptr;
-  }
-
-  template <typename U>
-  explicit operator RefPtr<U> () const;
-
-  explicit operator bool() const {
-    return m_ptr ? true : false;
-  }
-
-  bool isTheLastRef() const {
-    FBASSERT(m_ptr);
-    return m_ptr->hasOnlyOneRef();
-  }
-
-  // Creates a strong reference from a raw pointer, assuming that is already
-  // referenced from some other RefPtr. This should be used sparingly.
-  static inline RefPtr<T> assumeAlreadyReffed(T* ptr) {
-    return RefPtr<T>(ptr, ConstructionMode::External);
-  }
-
-  // Creates a strong reference from a raw pointer, assuming that it points to a
-  // freshly-created object. See the documentation for RefPtr for usage.
-  static inline RefPtr<T> adoptRef(T* ptr) {
-    return RefPtr<T>(ptr, ConstructionMode::Adopted);
-  }
-
-private:
-  enum class ConstructionMode {
-    Adopted,
-    External
-  };
-
-  RefPtr(T* ptr, ConstructionMode mode) :
-    m_ptr(ptr)
-  {
-    FBASSERTMSGF(ptr, "Got null pointer in %s construction mode", mode == ConstructionMode::Adopted ? "adopted" : "external");
-    ptr->ref();
-    if (mode == ConstructionMode::Adopted) {
-      FBASSERT(ptr->hasOnlyOneRef());
-    }
-  }
-
-  static inline void refIfNecessary(T* ptr) {
-    if (ptr) {
-      ptr->ref();
-    }
-  }
-  static inline void unrefIfNecessary(T* ptr) {
-    if (ptr) {
-      ptr->unref();
-    }
-  }
-
-  template <typename U> friend class RefPtr;
-
-  T* m_ptr;
-};
-
-// Creates a strong reference from a raw pointer, assuming that is already
-// referenced from some other RefPtr and that it is non-null. This should be
-// used sparingly.
-template <typename T>
-static inline RefPtr<T> assumeAlreadyReffed(T* ptr) {
-  return RefPtr<T>::assumeAlreadyReffed(ptr);
-}
-
-// As above, but tolerant of nullptr.
-template <typename T>
-static inline RefPtr<T> assumeAlreadyReffedOrNull(T* ptr) {
-  return ptr ? RefPtr<T>::assumeAlreadyReffed(ptr) : nullptr;
-}
-
-// Creates a strong reference from a raw pointer, assuming that it points to a
-// freshly-created object. See the documentation for RefPtr for usage.
-template <typename T>
-static inline RefPtr<T> adoptRef(T* ptr) {
-  return RefPtr<T>::adoptRef(ptr);
-}
-
-template <typename T, typename ...Args>
-static inline RefPtr<T> createNew(Args&&... arguments) {
-  return RefPtr<T>::adoptRef(new T(std::forward<Args>(arguments)...));
-}
-
-template <typename T> template <typename U>
-RefPtr<T>::operator RefPtr<U>() const {
-  static_assert(std::is_base_of<T, U>::value, "Invalid static cast");
-  return assumeAlreadyReffedOrNull<U>(static_cast<U*>(m_ptr));
-}
-
-template <typename T, typename U>
-inline bool operator==(const RefPtr<T>& a, const RefPtr<U>& b) {
-  return a.get() == b.get();
-}
-
-template <typename T, typename U>
-inline bool operator!=(const RefPtr<T>& a, const RefPtr<U>& b) {
-  return a.get() != b.get();
-}
-
-template <typename T, typename U>
-inline bool operator==(const RefPtr<T>& ref, U* ptr) {
-  return ref.get() == ptr;
-}
-
-template <typename T, typename U>
-inline bool operator!=(const RefPtr<T>& ref, U* ptr) {
-  return ref.get() != ptr;
-}
-
-template <typename T, typename U>
-inline bool operator==(U* ptr, const RefPtr<T>& ref) {
-  return ref.get() == ptr;
-}
-
-template <typename T, typename U>
-inline bool operator!=(U* ptr, const RefPtr<T>& ref) {
-  return ref.get() != ptr;
-}
-
-template <typename T>
-inline bool operator==(const RefPtr<T>& ref, std::nullptr_t ptr) {
-  return ref.get() == ptr;
-}
-
-template <typename T>
-inline bool operator!=(const RefPtr<T>& ref, std::nullptr_t ptr) {
-  return ref.get() != ptr;
-}
-
-template <typename T>
-inline bool operator==(std::nullptr_t ptr, const RefPtr<T>& ref) {
-  return ref.get() == ptr;
-}
-
-template <typename T>
-inline bool operator!=(std::nullptr_t ptr, const RefPtr<T>& ref) {
-  return ref.get() != ptr;
-}
-
-}

lib/fb/src/main/cpp/include/fb/StaticInitialized.h

@@ -1,37 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-#include <fb/assert.h>
-#include <utility>
-
-namespace facebook {
-
-// Class that lets you declare a global but does not add a static constructor
-// to the binary. Eventually I'd like to have this auto-initialize in a
-// multithreaded environment but for now it's easiest just to use manual
-// initialization.
-template <typename T>
-class StaticInitialized {
-public:
-  constexpr StaticInitialized() :
-    m_instance(nullptr)
-  {}
-
-  template <typename ...Args>
-  void initialize(Args&&... arguments) {
-    FBASSERT(!m_instance);
-    m_instance = new T(std::forward<Args>(arguments)...);
-  }
-
-  T* operator->() const {
-    return m_instance;
-  }
-private:
-  T* m_instance;
-};
-
-}

lib/fb/src/main/cpp/include/fb/ThreadLocal.h

@@ -1,115 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-#include <pthread.h>
-#include <errno.h>
-
-#include <fb/assert.h>
-
-namespace facebook {
-
-///////////////////////////////////////////////////////////////////////////////
-
-/**
- * A thread-local object is a "global" object within a thread. This is useful
- * for writing apartment-threaded code, where nothing is actullay shared
- * between different threads (hence no locking) but those variables are not
- * on stack in local scope. To use it, just do something like this,
- *
- *   ThreadLocal<MyClass> static_object;
- *     static_object->data_ = ...;
- *     static_object->doSomething();
- *
- *   ThreadLocal<int> static_number;
- *     int value = *static_number;
- *
- * So, syntax-wise it's similar to pointers. T can be primitive types, and if
- * it's a class, there has to be a default constructor.
- */
-template<typename T>
-class ThreadLocal {
-public:
-  /**
-   * Constructor that has to be called from a thread-neutral place.
-   */
-  ThreadLocal() :
-    m_key(0),
-    m_cleanup(OnThreadExit) {
-    initialize();
-  }
-
-  /**
-   * As above but with a custom cleanup function
-   */
-  typedef void (*CleanupFunction)(void* obj);
-  explicit ThreadLocal(CleanupFunction cleanup) :
-    m_key(0),
-    m_cleanup(cleanup) {
-    FBASSERT(cleanup);
-    initialize();
-  }
-
-  /**
-   * Access object's member or method through this operator overload.
-   */
-  T *operator->() const {
-    return get();
-  }
-
-  T &operator*() const {
-    return *get();
-  }
-
-  T *get() const {
-    return (T*)pthread_getspecific(m_key);
-  }
-
-  T* release() {
-    T* obj = get();
-    pthread_setspecific(m_key, NULL);
-    return obj;
-  }
-
-  void reset(T* other = NULL) {
-    T* old = (T*)pthread_getspecific(m_key);
-    if (old != other) {
-      FBASSERT(m_cleanup);
-      m_cleanup(old);
-      pthread_setspecific(m_key, other);
-    }
-  }
-
-private:
-  void initialize() {
-    int ret = pthread_key_create(&m_key, m_cleanup);
-    if (ret != 0) {
-      const char *msg = "(unknown error)";
-      switch (ret) {
-      case EAGAIN:
-        msg = "PTHREAD_KEYS_MAX (1024) is exceeded";
-        break;
-      case ENOMEM:
-        msg = "Out-of-memory";
-        break;
-      }
-      (void) msg;
-      FBASSERTMSGF(0, "pthread_key_create failed: %d %s", ret, msg);
-    }
-  }
-
-  static void OnThreadExit(void *obj) {
-    if (NULL != obj) {
-      delete (T*)obj;
-    }
-  }
-
-  pthread_key_t m_key;
-  CleanupFunction m_cleanup;
-};
-
-}

lib/fb/src/main/cpp/include/fb/assert.h

@@ -1,33 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#ifndef FBASSERT_H
-#define FBASSERT_H
-
-#include <fb/visibility.h>
-
-namespace facebook {
-#define ENABLE_FBASSERT 1
-
-#if ENABLE_FBASSERT
-#define FBASSERTMSGF(expr, msg, ...) !(expr) ? facebook::assertInternal("Assert (%s:%d): " msg, __FILE__, __LINE__, ##__VA_ARGS__) : (void) 0
-#else
-#define FBASSERTMSGF(expr, msg, ...)
-#endif // ENABLE_FBASSERT
-
-#define FBASSERT(expr) FBASSERTMSGF(expr, "%s", #expr)
-
-#define FBCRASH(msg, ...) facebook::assertInternal("Fatal error (%s:%d): " msg, __FILE__, __LINE__, ##__VA_ARGS__)
-#define FBUNREACHABLE() facebook::assertInternal("This code should be unreachable (%s:%d)", __FILE__, __LINE__)
-
-FBEXPORT void assertInternal(const char* formatstr, ...) __attribute__((noreturn));
-
-// This allows storing the assert message before the current process terminates due to a crash
-typedef void (*AssertHandler)(const char* message);
-void setAssertHandler(AssertHandler assertHandler);
-
-} // namespace facebook
-#endif // FBASSERT_H

lib/fb/src/main/cpp/include/fb/fbjni.h

@@ -1,21 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-#include <jni.h>
-
-#include <fb/Environment.h>
-#include <fb/ALog.h>
-#include <fb/fbjni/Common.h>
-#include <fb/fbjni/Exceptions.h>
-#include <fb/fbjni/ReferenceAllocators.h>
-#include <fb/fbjni/References.h>
-#include <fb/fbjni/Meta.h>
-#include <fb/fbjni/CoreClasses.h>
-#include <fb/fbjni/Iterator.h>
-#include <fb/fbjni/Hybrid.h>
-#include <fb/fbjni/Registration.h>

lib/fb/src/main/cpp/include/fb/fbjni/JThread.h

@@ -1,36 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-#include "CoreClasses.h"
-#include "NativeRunnable.h"
-
-namespace facebook {
-namespace jni {
-
-class JThread : public JavaClass<JThread> {
- public:
-  static constexpr const char* kJavaDescriptor = "Ljava/lang/Thread;";
-
-  void start() {
-    static auto method = javaClassStatic()->getMethod<void()>("start");
-    method(self());
-  }
-
-  void join() {
-    static auto method = javaClassStatic()->getMethod<void()>("join");
-    method(self());
-  }
-
-  static local_ref<JThread> create(std::function<void()>&& runnable) {
-    auto jrunnable = JNativeRunnable::newObjectCxxArgs(std::move(runnable));
-    return newInstance(static_ref_cast<JRunnable::javaobject>(jrunnable));
-  }
-};
-
-}
-}

lib/fb/src/main/cpp/include/fb/fbjni/Registration-inl.h

@@ -1,206 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-#include "Exceptions.h"
-#include "Hybrid.h"
-
-namespace facebook {
-namespace jni {
-
-namespace detail {
-
-#ifdef __i386__
-// X86 ABI forces 16 byte stack allignment on calls. Unfortunately
-// sometimes Dalvik chooses not to obey the ABI:
-// - https://code.google.com/p/android/issues/detail?id=61012
-// - https://android.googlesource.com/platform/ndk/+/81696d2%5E!/
-// Therefore, we tell the compiler to re-align the stack on entry
-// to our JNI functions.
-#define JNI_ENTRY_POINT __attribute__((force_align_arg_pointer))
-#else
-#define JNI_ENTRY_POINT
-#endif
-
-// registration wrapper for legacy JNI-style functions
-
-template<typename F, F func, typename C, typename... Args>
-inline NativeMethodWrapper* exceptionWrapJNIMethod(void (*)(JNIEnv*, C, Args... args)) {
-  struct funcWrapper {
-    JNI_ENTRY_POINT static void call(JNIEnv* env, jobject obj, Args... args) {
-      // Note that if func was declared noexcept, then both gcc and clang are smart
-      // enough to elide the try/catch.
-      try {
-        (*func)(env, static_cast<C>(obj), args...);
-      } catch (...) {
-        translatePendingCppExceptionToJavaException();
-      }
-    }
-  };
-
-  // This intentionally erases the real type; JNI will do it anyway
-  return reinterpret_cast<NativeMethodWrapper*>(&(funcWrapper::call));
-}
-
-template<typename F, F func, typename C, typename R, typename... Args>
-inline NativeMethodWrapper* exceptionWrapJNIMethod(R (*)(JNIEnv*, C, Args... args)) {
-  struct funcWrapper {
-    JNI_ENTRY_POINT static R call(JNIEnv* env, jobject obj, Args... args) {
-      try {
-        return (*func)(env, static_cast<JniType<C>>(obj), args...);
-      } catch (...) {
-        translatePendingCppExceptionToJavaException();
-        return R{};
-      }
-    }
-  };
-
-  // This intentionally erases the real type; JNI will do it anyway
-  return reinterpret_cast<NativeMethodWrapper*>(&(funcWrapper::call));
-}
-
-// registration wrappers for functions, with autoconversion of arguments.
-
-template<typename F, F func, typename C, typename... Args>
-inline NativeMethodWrapper* exceptionWrapJNIMethod(void (*)(alias_ref<C>, Args... args)) {
-  struct funcWrapper {
-    JNI_ENTRY_POINT static void call(JNIEnv*, jobject obj,
-                                     typename Convert<typename std::decay<Args>::type>::jniType... args) {
-      try {
-        (*func)(static_cast<JniType<C>>(obj), Convert<typename std::decay<Args>::type>::fromJni(args)...);
-      } catch (...) {
-        translatePendingCppExceptionToJavaException();
-      }
-    }
-  };
-
-  // This intentionally erases the real type; JNI will do it anyway
-  return reinterpret_cast<NativeMethodWrapper*>(&(funcWrapper::call));
-}
-
-template<typename F, F func, typename C, typename R, typename... Args>
-inline NativeMethodWrapper* exceptionWrapJNIMethod(R (*)(alias_ref<C>, Args... args)) {
-  struct funcWrapper {
-
-    JNI_ENTRY_POINT static typename Convert<typename std::decay<R>::type>::jniType call(JNIEnv*, jobject obj,
-                                       typename Convert<typename std::decay<Args>::type>::jniType... args) {
-      try {
-        return Convert<typename std::decay<R>::type>::toJniRet(
-          (*func)(static_cast<JniType<C>>(obj), Convert<typename std::decay<Args>::type>::fromJni(args)...));
-      } catch (...) {
-        using jniRet = typename Convert<typename std::decay<R>::type>::jniType;
-        translatePendingCppExceptionToJavaException();
-        return jniRet{};
-      }
-    }
-  };
-
-  // This intentionally erases the real type; JNI will do it anyway
-  return reinterpret_cast<NativeMethodWrapper*>(&(funcWrapper::call));
-}
-
-// registration wrappers for non-static methods, with autoconvertion of arguments.
-
-template <typename M, M method, typename C, typename... Args>
-inline NativeMethodWrapper* exceptionWrapJNIMethod(
-    void (C::*method0)(Args... args)) {
-  (void)method0;
-  struct funcWrapper {
-    JNI_ENTRY_POINT static void call(JNIEnv* env, jobject obj,
-                                     typename Convert<typename std::decay<Args>::type>::jniType... args) {
-      try {
-        try {
-          auto aref = wrap_alias(static_cast<typename C::jhybridobject>(obj));
-          // This is usually a noop, but if the hybrid object is a
-          // base class of other classes which register JNI methods,
-          // this will get the right type for the registered method.
-          auto cobj = static_cast<C*>(facebook::jni::cthis(aref));
-          (cobj->*method)(Convert<typename std::decay<Args>::type>::fromJni(args)...);
-        } catch (const std::exception& ex) {
-          C::mapException(ex);
-          throw;
-        }
-      } catch (...) {
-        translatePendingCppExceptionToJavaException();
-      }
-    }
-  };
-
-  // This intentionally erases the real type; JNI will do it anyway
-  return reinterpret_cast<NativeMethodWrapper*>(&(funcWrapper::call));
-}
-
-template<typename M, M method, typename C, typename R, typename... Args>
-inline NativeMethodWrapper* exceptionWrapJNIMethod(R (C::*method0)(Args... args)) {
-  struct funcWrapper {
-
-    JNI_ENTRY_POINT static typename Convert<typename std::decay<R>::type>::jniType call(JNIEnv* env, jobject obj,
-                                       typename Convert<typename std::decay<Args>::type>::jniType... args) {
-      try {
-        try {
-          auto aref = wrap_alias(static_cast<typename C::jhybridobject>(obj));
-          // This is usually a noop, but if the hybrid object is a
-          // base class of other classes which register JNI methods,
-          // this will get the right type for the registered method.
-          auto cobj = static_cast<C*>(facebook::jni::cthis(aref));
-          return Convert<typename std::decay<R>::type>::toJniRet(
-            (cobj->*method)(Convert<typename std::decay<Args>::type>::fromJni(args)...));
-        } catch (const std::exception& ex) {
-          C::mapException(ex);
-          throw;
-        }
-      } catch (...) {
-        using jniRet = typename Convert<typename std::decay<R>::type>::jniType;
-        translatePendingCppExceptionToJavaException();
-        return jniRet{};
-      }
-    }
-  };
-
-  // This intentionally erases the real type; JNI will do it anyway
-  return reinterpret_cast<NativeMethodWrapper*>(&(funcWrapper::call));
-}
-
-template<typename R, typename C, typename... Args>
-inline std::string makeDescriptor(R (*)(JNIEnv*, C, Args... args)) {
-  return jmethod_traits<R(Args...)>::descriptor();
-}
-
-template<typename R, typename C, typename... Args>
-inline std::string makeDescriptor(R (*)(alias_ref<C>, Args... args)) {
-  return jmethod_traits_from_cxx<R(Args...)>::descriptor();
-}
-
-template<typename R, typename C, typename... Args>
-inline std::string makeDescriptor(R (C::*)(Args... args)) {
-  return jmethod_traits_from_cxx<R(Args...)>::descriptor();
-}
-
-template <typename R, typename... Args>
-template <R (*func)(Args...)>
-JNI_ENTRY_POINT R CriticalMethod<R (*)(Args...)>::call(
-    alias_ref<jclass>,
-    Args... args) noexcept {
-  static_assert(
-      IsJniPrimitive<R>() || std::is_void<R>(),
-      "Critical Native Methods may only return primitive JNI types, or void.");
-  static_assert(
-      AreJniPrimitives<Args...>(),
-      "Critical Native Methods may only use primitive JNI types as parameters");
-
-  return func(std::forward<Args>(args)...);
-}
-
-template <typename R, typename... Args>
-template <R (*func)(Args...)>
-inline std::string CriticalMethod<R (*)(Args...)>::desc() {
-  return makeDescriptor(call<func>);
-}
-
-}
-
-}}

lib/fb/src/main/cpp/include/fb/log.h

@@ -1,346 +0,0 @@
-/*
- * Copyright (C) 2005 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/*
- * FB Wrapper for logging functions.
- *
- * The android logging API uses the macro "LOG()" for its logic, which means
- * that it conflicts with random other places that use LOG for their own
- * purposes and doesn't work right half the places you include it
- *
- * FBLOG uses exactly the same semantics (FBLOGD for debug etc) but because of
- * the FB prefix it's strictly better. FBLOGV also gets stripped out based on
- * whether NDEBUG is set, but can be overridden by FBLOG_NDEBUG
- *
- * Most of the rest is a copy of <cutils/log.h> with minor changes.
- */
-
-//
-// C/C++ logging functions.  See the logging documentation for API details.
-//
-// We'd like these to be available from C code (in case we import some from
-// somewhere), so this has a C interface.
-//
-// The output will be correct when the log file is shared between multiple
-// threads and/or multiple processes so long as the operating system
-// supports O_APPEND.  These calls have mutex-protected data structures
-// and so are NOT reentrant.  Do not use LOG in a signal handler.
-//
-#pragma once
-
-#include <fb/visibility.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#ifdef ANDROID
-#include <android/log.h>
-#else
-// These declarations are needed for our internal use even on non-Android
-// builds.
-// (they are borrowed from <android/log.h>)
-
-/*
- * Android log priority values, in ascending priority order.
- */
-typedef enum android_LogPriority {
-  ANDROID_LOG_UNKNOWN = 0,
-  ANDROID_LOG_DEFAULT, /* only for SetMinPriority() */
-  ANDROID_LOG_VERBOSE,
-  ANDROID_LOG_DEBUG,
-  ANDROID_LOG_INFO,
-  ANDROID_LOG_WARN,
-  ANDROID_LOG_ERROR,
-  ANDROID_LOG_FATAL,
-  ANDROID_LOG_SILENT, /* only for SetMinPriority(); must be last */
-} android_LogPriority;
-
-/*
- * Send a simple string to the log.
- */
-int __android_log_write(int prio, const char *tag, const char *text);
-
-/*
- * Send a formatted string to the log, used like printf(fmt,...)
- */
-int __android_log_print(int prio, const char *tag, const char *fmt, ...)
-#if defined(__GNUC__)
-    __attribute__((format(printf, 3, 4)))
-#endif
-    ;
-
-#endif
-
-// ---------------------------------------------------------------------
-
-/*
- * Normally we strip FBLOGV (VERBOSE messages) from release builds.
- * You can modify this (for example with "#define FBLOG_NDEBUG 0"
- * at the top of your source file) to change that behavior.
- */
-#ifndef FBLOG_NDEBUG
-#ifdef NDEBUG
-#define FBLOG_NDEBUG 1
-#else
-#define FBLOG_NDEBUG 0
-#endif
-#endif
-
-/*
- * This is the local tag used for the following simplified
- * logging macros.  You can change this preprocessor definition
- * before using the other macros to change the tag.
- */
-#ifndef LOG_TAG
-#define LOG_TAG NULL
-#endif
-
-// ---------------------------------------------------------------------
-
-/*
- * Simplified macro to send a verbose log message using the current LOG_TAG.
- */
-#ifndef FBLOGV
-#if FBLOG_NDEBUG
-#define FBLOGV(...) ((void)0)
-#else
-#define FBLOGV(...) ((void)FBLOG(LOG_VERBOSE, LOG_TAG, __VA_ARGS__))
-#endif
-#endif
-
-#define CONDITION(cond) (__builtin_expect((cond) != 0, 0))
-
-#ifndef FBLOGV_IF
-#if FBLOG_NDEBUG
-#define FBLOGV_IF(cond, ...) ((void)0)
-#else
-#define FBLOGV_IF(cond, ...)                                            \
-  ((CONDITION(cond)) ? ((void)FBLOG(LOG_VERBOSE, LOG_TAG, __VA_ARGS__)) \
-                     : (void)0)
-#endif
-#endif
-
-/*
- * Simplified macro to send a debug log message using the current LOG_TAG.
- */
-#ifndef FBLOGD
-#define FBLOGD(...) ((void)FBLOG(LOG_DEBUG, LOG_TAG, __VA_ARGS__))
-#endif
-
-#ifndef FBLOGD_IF
-#define FBLOGD_IF(cond, ...) \
-  ((CONDITION(cond)) ? ((void)FBLOG(LOG_DEBUG, LOG_TAG, __VA_ARGS__)) : (void)0)
-#endif
-
-/*
- * Simplified macro to send an info log message using the current LOG_TAG.
- */
-#ifndef FBLOGI
-#define FBLOGI(...) ((void)FBLOG(LOG_INFO, LOG_TAG, __VA_ARGS__))
-#endif
-
-#ifndef FBLOGI_IF
-#define FBLOGI_IF(cond, ...) \
-  ((CONDITION(cond)) ? ((void)FBLOG(LOG_INFO, LOG_TAG, __VA_ARGS__)) : (void)0)
-#endif
-
-/*
- * Simplified macro to send a warning log message using the current LOG_TAG.
- */
-#ifndef FBLOGW
-#define FBLOGW(...) ((void)FBLOG(LOG_WARN, LOG_TAG, __VA_ARGS__))
-#endif
-
-#ifndef FBLOGW_IF
-#define FBLOGW_IF(cond, ...) \
-  ((CONDITION(cond)) ? ((void)FBLOG(LOG_WARN, LOG_TAG, __VA_ARGS__)) : (void)0)
-#endif
-
-/*
- * Simplified macro to send an error log message using the current LOG_TAG.
- */
-#ifndef FBLOGE
-#define FBLOGE(...) ((void)FBLOG(LOG_ERROR, LOG_TAG, __VA_ARGS__))
-#endif
-
-#ifndef FBLOGE_IF
-#define FBLOGE_IF(cond, ...) \
-  ((CONDITION(cond)) ? ((void)FBLOG(LOG_ERROR, LOG_TAG, __VA_ARGS__)) : (void)0)
-#endif
-
-// ---------------------------------------------------------------------
-
-/*
- * Conditional based on whether the current LOG_TAG is enabled at
- * verbose priority.
- */
-#ifndef IF_FBLOGV
-#if FBLOG_NDEBUG
-#define IF_FBLOGV() if (false)
-#else
-#define IF_FBLOGV() IF_FBLOG(LOG_VERBOSE, LOG_TAG)
-#endif
-#endif
-
-/*
- * Conditional based on whether the current LOG_TAG is enabled at
- * debug priority.
- */
-#ifndef IF_FBLOGD
-#define IF_FBLOGD() IF_FBLOG(LOG_DEBUG, LOG_TAG)
-#endif
-
-/*
- * Conditional based on whether the current LOG_TAG is enabled at
- * info priority.
- */
-#ifndef IF_FBLOGI
-#define IF_FBLOGI() IF_FBLOG(LOG_INFO, LOG_TAG)
-#endif
-
-/*
- * Conditional based on whether the current LOG_TAG is enabled at
- * warn priority.
- */
-#ifndef IF_FBLOGW
-#define IF_FBLOGW() IF_FBLOG(LOG_WARN, LOG_TAG)
-#endif
-
-/*
- * Conditional based on whether the current LOG_TAG is enabled at
- * error priority.
- */
-#ifndef IF_FBLOGE
-#define IF_FBLOGE() IF_FBLOG(LOG_ERROR, LOG_TAG)
-#endif
-
-// ---------------------------------------------------------------------
-
-/*
- * Log a fatal error.  If the given condition fails, this stops program
- * execution like a normal assertion, but also generating the given message.
- * It is NOT stripped from release builds.  Note that the condition test
- * is -inverted- from the normal assert() semantics.
- */
-#define FBLOG_ALWAYS_FATAL_IF(cond, ...)                                   \
-  ((CONDITION(cond)) ? ((void)fb_printAssert(#cond, LOG_TAG, __VA_ARGS__)) \
-                     : (void)0)
-
-#define FBLOG_ALWAYS_FATAL(...) \
-  (((void)fb_printAssert(NULL, LOG_TAG, __VA_ARGS__)))
-
-/*
- * Versions of LOG_ALWAYS_FATAL_IF and LOG_ALWAYS_FATAL that
- * are stripped out of release builds.
- */
-#if FBLOG_NDEBUG
-
-#define FBLOG_FATAL_IF(cond, ...) ((void)0)
-#define FBLOG_FATAL(...) ((void)0)
-
-#else
-
-#define FBLOG_FATAL_IF(cond, ...) FBLOG_ALWAYS_FATAL_IF(cond, __VA_ARGS__)
-#define FBLOG_FATAL(...) FBLOG_ALWAYS_FATAL(__VA_ARGS__)
-
-#endif
-
-/*
- * Assertion that generates a log message when the assertion fails.
- * Stripped out of release builds.  Uses the current LOG_TAG.
- */
-#define FBLOG_ASSERT(cond, ...) FBLOG_FATAL_IF(!(cond), __VA_ARGS__)
-//#define LOG_ASSERT(cond) LOG_FATAL_IF(!(cond), "Assertion failed: " #cond)
-
-// ---------------------------------------------------------------------
-
-/*
- * Basic log message macro.
- *
- * Example:
- *  FBLOG(LOG_WARN, NULL, "Failed with error %d", errno);
- *
- * The second argument may be NULL or "" to indicate the "global" tag.
- */
-#ifndef FBLOG
-#define FBLOG(priority, tag, ...) \
-  FBLOG_PRI(ANDROID_##priority, tag, __VA_ARGS__)
-#endif
-
-#ifndef FBLOG_BY_DELIMS
-#define FBLOG_BY_DELIMS(priority, tag, delims, msg, ...) \
-  logPrintByDelims(ANDROID_##priority, tag, delims, msg, ##__VA_ARGS__)
-#endif
-
-/*
- * Log macro that allows you to specify a number for the priority.
- */
-#ifndef FBLOG_PRI
-#define FBLOG_PRI(priority, tag, ...) fb_printLog(priority, tag, __VA_ARGS__)
-#endif
-
-/*
- * Log macro that allows you to pass in a varargs ("args" is a va_list).
- */
-#ifndef FBLOG_PRI_VA
-#define FBLOG_PRI_VA(priority, tag, fmt, args) \
-  fb_vprintLog(priority, NULL, tag, fmt, args)
-#endif
-
-/*
- * Conditional given a desired logging priority and tag.
- */
-#ifndef IF_FBLOG
-#define IF_FBLOG(priority, tag) if (fb_testLog(ANDROID_##priority, tag))
-#endif
-
-typedef void (*LogHandler)(int priority, const char* tag, const char* message);
-FBEXPORT void setLogHandler(LogHandler logHandler);
-
-/*
- * ===========================================================================
- *
- * The stuff in the rest of this file should not be used directly.
- */
-FBEXPORT int fb_printLog(int prio, const char* tag, const char* fmt, ...)
-#if defined(__GNUC__)
-    __attribute__((format(printf, 3, 4)))
-#endif
-    ;
-
-#define fb_vprintLog(prio, cond, tag, fmt...) \
-  __android_log_vprint(prio, tag, fmt)
-
-#define fb_printAssert(cond, tag, fmt...) __android_log_assert(cond, tag, fmt)
-
-#define fb_writeLog(prio, tag, text) __android_log_write(prio, tag, text)
-
-#define fb_bWriteLog(tag, payload, len) __android_log_bwrite(tag, payload, len)
-#define fb_btWriteLog(tag, type, payload, len) \
-  __android_log_btwrite(tag, type, payload, len)
-
-#define fb_testLog(prio, tag) (1)
-
-/*
- * FB extensions
- */
-void logPrintByDelims(int priority, const char* tag, const char* delims,
-                      const char* msg, ...);
-
-#ifdef __cplusplus
-}
-#endif

lib/fb/src/main/cpp/include/fb/noncopyable.h

@@ -1,18 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-namespace facebook {
-
-struct noncopyable {
-  noncopyable(const noncopyable&) = delete;
-  noncopyable& operator=(const noncopyable&) = delete;
-protected:
-  noncopyable() = default;
-};
-
-}

lib/fb/src/main/cpp/include/fb/nonmovable.h

@@ -1,18 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-namespace facebook {
-
-struct nonmovable {
-  nonmovable(nonmovable&&) = delete;
-  nonmovable& operator=(nonmovable&&) = delete;
-protected:
-  nonmovable() = default;
-};
-
-}

lib/fb/src/main/cpp/include/fbjni/ByteBuffer.h

@@ -6,26 +6,37 @@
  */
 #pragma once
 
-#include <fb/visibility.h>
+#include <fbjni/fbjni.h>
-
-#include "CoreClasses.h"
-#include "References-forward.h"
 
 namespace facebook {
 namespace jni {
 
+class JBuffer : public JavaClass<JBuffer> {
+public:
+  static constexpr const char* kJavaDescriptor = "Ljava/nio/Buffer;";
+
+  void rewind() const;
+  bool isDirect() const;
+  void* getDirectAddress() const;
+  size_t getDirectCapacity() const;
+};
+
 // JNI's NIO support has some awkward preconditions and error reporting. This
 // class provides much more user-friendly access.
-class FBEXPORT JByteBuffer : public JavaClass<JByteBuffer> {
+class JByteBuffer : public JavaClass<JByteBuffer, JBuffer> {
  public:
   static constexpr const char* kJavaDescriptor = "Ljava/nio/ByteBuffer;";
 
   static local_ref<JByteBuffer> wrapBytes(uint8_t* data, size_t size);
+  static local_ref<JByteBuffer> allocateDirect(jint size);
 
-  bool isDirect() const;
+  uint8_t* getDirectBytes() const {
+    return static_cast<uint8_t*>(getDirectAddress());
+  }
 
-  uint8_t* getDirectBytes() const;
+  size_t getDirectSize() const {
-  size_t getDirectSize() const;
+    return getDirectCapacity();
+  }
 };
 
 }}

lib/fb/src/main/cpp/include/fbjni/Context.h

@@ -6,8 +6,8 @@
  */
 #pragma once
 
-#include "CoreClasses.h"
+#include <fbjni/fbjni.h>
-#include "File.h"
+#include <fbjni/File.h>
 
 namespace facebook {
 namespace jni {
@@ -18,12 +18,12 @@ class AContext : public JavaClass<AContext> {
 
   // Define a method that calls into the represented Java class
   local_ref<JFile::javaobject> getCacheDir() {
-    static auto method = getClass()->getMethod<JFile::javaobject()>("getCacheDir");
+    static const auto method = getClass()->getMethod<JFile::javaobject()>("getCacheDir");
     return method(self());
   }
 
   local_ref<JFile::javaobject> getFilesDir() {
-    static auto method = getClass()->getMethod<JFile::javaobject()>("getFilesDir");
+    static const auto method = getClass()->getMethod<JFile::javaobject()>("getFilesDir");
     return method(self());
   }
 };

lib/fb/src/main/cpp/include/fbjni/File.h

@@ -6,7 +6,7 @@
  */
 #pragma once
 
-#include "CoreClasses.h"
+#include <fbjni/fbjni.h>
 
 namespace facebook {
 namespace jni {
@@ -17,7 +17,7 @@ class JFile : public JavaClass<JFile> {
 
   // Define a method that calls into the represented Java class
   std::string getAbsolutePath() {
-    static auto method = getClass()->getMethod<jstring()>("getAbsolutePath");
+    static const auto method = getClass()->getMethod<jstring()>("getAbsolutePath");
     return method(self())->toStdString();
   }
 

lib/fb/src/main/cpp/include/fbjni/JThread.h

@@ -0,0 +1,56 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#pragma once
+
+#include <fbjni/fbjni.h>
+#include <fbjni/NativeRunnable.h>
+
+namespace facebook {
+namespace jni {
+
+class JThread : public JavaClass<JThread> {
+ public:
+  static constexpr const char* kJavaDescriptor = "Ljava/lang/Thread;";
+
+  void start() {
+    static const auto method = javaClassStatic()->getMethod<void()>("start");
+    method(self());
+  }
+
+  void join() {
+    static const auto method = javaClassStatic()->getMethod<void()>("join");
+    method(self());
+  }
+
+  static local_ref<JThread> create(std::function<void()>&& runnable) {
+    auto jrunnable = JNativeRunnable::newObjectCxxArgs(std::move(runnable));
+    return newInstance(static_ref_cast<JRunnable::javaobject>(jrunnable));
+  }
+
+  static local_ref<JThread> create(std::function<void()>&& runnable, std::string&& name) {
+    auto jrunnable = JNativeRunnable::newObjectCxxArgs(std::move(runnable));
+    return newInstance(static_ref_cast<JRunnable::javaobject>(jrunnable), make_jstring(std::move(name)));
+  }
+
+  static local_ref<JThread> getCurrent() {
+    static const auto method = javaClassStatic()->getStaticMethod<local_ref<JThread>()>("currentThread");
+    return method(javaClassStatic());
+  }
+
+  int getPriority() {
+    static const auto method = getClass()->getMethod<jint()>("getPriority");
+    return method(self());
+  }
+
+  void setPriority(int priority) {
+    static const auto method = getClass()->getMethod<void(int)>("setPriority");
+    method(self(), priority);
+  }
+};
+
+}
+}

lib/fb/src/main/cpp/include/fbjni/NativeRunnable.h

@@ -6,9 +6,7 @@
  */
 #pragma once
 
-#include "CoreClasses.h"
+#include <fbjni/fbjni.h>
-#include "Hybrid.h"
-#include "Registration.h"
 
 #include <functional>
 

lib/fb/src/main/cpp/include/fbjni/ReadableByteChannel.h

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#pragma once
+
+#include <fbjni/fbjni.h>
+#include <fbjni/ByteBuffer.h>
+
+namespace facebook {
+namespace jni {
+
+class JReadableByteChannel : public JavaClass<JReadableByteChannel> {
+public:
+  static constexpr const char* kJavaDescriptor = "Ljava/nio/channels/ReadableByteChannel;";
+
+  int read(alias_ref<JByteBuffer> dest) const;
+};
+
+}}

lib/fb/src/main/cpp/include/fbjni/detail/Boxed.h

@@ -17,13 +17,13 @@ struct JPrimitive : JavaClass<T> {
   using typename JavaClass<T>::javaobject;
   using JavaClass<T>::javaClassStatic;
   static local_ref<javaobject> valueOf(jprim val) {
-    static auto cls = javaClassStatic();
+    static const auto cls = javaClassStatic();
-    static auto method =
+    static const auto method =
       cls->template getStaticMethod<javaobject(jprim)>("valueOf");
     return method(cls, val);
   }
   jprim value() const {
-    static auto method =
+    static const auto method =
       javaClassStatic()->template getMethod<jprim()>(T::kValueMethod);
     return method(this->self());
   }
@@ -55,9 +55,20 @@ DEFINE_BOXED_PRIMITIVE(double, Double)
 
 #undef DEFINE_BOXED_PRIMITIVE
 
+template<typename T>
+inline typename std::enable_if<
+  (std::is_same<T, long long>::value || std::is_same<T, int64_t>::value) && !std::is_same<T, jlong>::value,
+  local_ref<jobject>
+>::type autobox(T val) {
+  return JLong::valueOf(val);
+}
+
+struct JVoid : public jni::JavaClass<JVoid> {
+  static auto constexpr kJavaDescriptor = "Ljava/lang/Void;";
+};
+
 inline local_ref<jobject> autobox(alias_ref<jobject> val) {
   return make_local(val);
 }
 
 }}
-

lib/fb/src/main/cpp/include/fbjni/detail/Common.h

@@ -15,9 +15,6 @@
 
 #include <jni.h>
 
-#include <fb/visibility.h>
-#include <fb/Environment.h>
-
 #ifdef FBJNI_DEBUG_REFS
 # ifdef __ANDROID__
 #  include <android/log.h>
@@ -42,11 +39,11 @@
 namespace facebook {
 namespace jni {
 
-FBEXPORT void throwPendingJniExceptionAsCppException();
+void throwPendingJniExceptionAsCppException();
-FBEXPORT void throwCppExceptionIf(bool condition);
+void throwCppExceptionIf(bool condition);
 
-[[noreturn]] FBEXPORT void throwNewJavaException(jthrowable);
+[[noreturn]] void throwNewJavaException(jthrowable);
-[[noreturn]] FBEXPORT void throwNewJavaException(const char* throwableName, const char* msg);
+[[noreturn]] void throwNewJavaException(const char* throwableName, const char* msg);
 template<typename... Args>
 [[noreturn]] void throwNewJavaException(const char* throwableName, const char* fmt, Args... args);
 
@@ -65,20 +62,10 @@ template<typename... Args>
  * unhelpful way (typically a segfault) while trying to handle an exception
  * which occurs later.
  */
-FBEXPORT jint initialize(JavaVM*, std::function<void()>&&) noexcept;
+jint initialize(JavaVM*, std::function<void()>&&) noexcept;
 
 namespace internal {
 
-/**
- * Retrieve a pointer the JNI environment of the current thread.
- *
- * @pre The current thread must be attached to the VM
- */
-inline JNIEnv* getEnv() noexcept {
-  // TODO(T6594868) Benchmark against raw JNI access
-  return Environment::current();
-}
-
 // Define to get extremely verbose logging of references and to enable reference stats
 #ifdef FBJNI_DEBUG_REFS
 template<typename... Args>

lib/fb/src/main/cpp/include/fbjni/detail/CoreClasses-inl.h

@@ -21,15 +21,15 @@ namespace jni {
 // jobject /////////////////////////////////////////////////////////////////////////////////////////
 
 inline bool isSameObject(alias_ref<JObject> lhs, alias_ref<JObject> rhs) noexcept {
-  return internal::getEnv()->IsSameObject(lhs.get(), rhs.get()) != JNI_FALSE;
+  return Environment::current()->IsSameObject(lhs.get(), rhs.get()) != JNI_FALSE;
 }
 
 inline local_ref<JClass> JObject::getClass() const noexcept {
-  return adopt_local(internal::getEnv()->GetObjectClass(self()));
+  return adopt_local(Environment::current()->GetObjectClass(self()));
 }
 
 inline bool JObject::isInstanceOf(alias_ref<JClass> cls) const noexcept {
-  return internal::getEnv()->IsInstanceOf(self(), cls.get()) != JNI_FALSE;
+  return Environment::current()->IsInstanceOf(self(), cls.get()) != JNI_FALSE;
 }
 
 template<typename T>
@@ -47,8 +47,13 @@ inline void JObject::setFieldValue(JField<T> field, T value) noexcept {
   field.set(self(), value);
 }
 
+template<typename T, typename>
+inline void JObject::setFieldValue(JField<T> field, alias_ref<T> value) noexcept {
+  setFieldValue(field, value.get());
+}
+
 inline std::string JObject::toString() const {
-  static auto method = findClassLocal("java/lang/Object")->getMethod<jstring()>("toString");
+  static const auto method = findClassLocal("java/lang/Object")->getMethod<jstring()>("toString");
 
   return method(self())->toStdString();
 }
@@ -77,13 +82,13 @@ MonitorLock::MonitorLock() noexcept : owned_(nullptr) {}
 
 MonitorLock::MonitorLock(alias_ref<JObject> object) noexcept
     : owned_(object) {
-  internal::getEnv()->MonitorEnter(object.get());
+  Environment::current()->MonitorEnter(object.get());
 }
 
 void MonitorLock::reset() noexcept {
   if (owned_) {
-    internal::getEnv()->MonitorExit(owned_.get());
+    Environment::current()->MonitorExit(owned_.get());
-    if (internal::getEnv()->ExceptionCheck()) {
+    if (Environment::current()->ExceptionCheck()) {
       abort(); // Lock mismatch
     }
     owned_ = nullptr;
@@ -126,7 +131,7 @@ namespace detail {
 template<typename JC, typename... Args>
 static local_ref<JC> newInstance(Args... args) {
   static auto cls = JC::javaClassStatic();
-  static auto constructor = cls->template getConstructor<typename JC::javaobject(Args...)>();
+  static const auto constructor = cls->template getConstructor<typename JC::javaobject(Args...)>();
   return cls->newObject(constructor, args...);
 }
 }
@@ -154,17 +159,18 @@ struct NativeMethod {
 };
 
 inline local_ref<JClass> JClass::getSuperclass() const noexcept {
-  return adopt_local(internal::getEnv()->GetSuperclass(self()));
+  return adopt_local(Environment::current()->GetSuperclass(self()));
 }
 
 inline void JClass::registerNatives(std::initializer_list<NativeMethod> methods) {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
 
   JNINativeMethod jnimethods[methods.size()];
   size_t i = 0;
   for (auto it = methods.begin(); it < methods.end(); ++it, ++i) {
-    jnimethods[i].name = it->name;
+    // The JNI struct members are unnecessarily non-const.
-    jnimethods[i].signature = it->descriptor.c_str();
+    jnimethods[i].name = const_cast<char*>(it->name);
+    jnimethods[i].signature = const_cast<char*>(it->descriptor.c_str());
     jnimethods[i].fnPtr = reinterpret_cast<void*>(it->wrapper);
   }
 
@@ -173,8 +179,13 @@ inline void JClass::registerNatives(std::initializer_list<NativeMethod> methods)
 }
 
 inline bool JClass::isAssignableFrom(alias_ref<JClass> other) const noexcept {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
-  const auto result = env->IsAssignableFrom(self(), other.get());
+  // Ths method has behavior compatible with the
+  // java.lang.Class#isAssignableFrom method.  The order of the
+  // arguments to the JNI IsAssignableFrom C function is "opposite"
+  // from what some might expect, which makes this code look a little
+  // odd, but it is correct.
+  const auto result = env->IsAssignableFrom(other.get(), self());
   return result;
 }
 
@@ -198,7 +209,7 @@ template<typename F>
 inline JMethod<F> JClass::getMethod(
     const char* name,
     const char* descriptor) const {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   const auto method = env->GetMethodID(self(), name, descriptor);
   FACEBOOK_JNI_THROW_EXCEPTION_IF(!method);
   return JMethod<F>{method};
@@ -213,7 +224,7 @@ template<typename F>
 inline JStaticMethod<F> JClass::getStaticMethod(
     const char* name,
     const char* descriptor) const {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   const auto method = env->GetStaticMethodID(self(), name, descriptor);
   FACEBOOK_JNI_THROW_EXCEPTION_IF(!method);
   return JStaticMethod<F>{method};
@@ -228,7 +239,7 @@ template<typename F>
 inline JNonvirtualMethod<F> JClass::getNonvirtualMethod(
     const char* name,
     const char* descriptor) const {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   const auto method = env->GetMethodID(self(), name, descriptor);
   FACEBOOK_JNI_THROW_EXCEPTION_IF(!method);
   return JNonvirtualMethod<F>{method};
@@ -244,7 +255,7 @@ template<typename T>
 inline JField<enable_if_t<IsJniScalar<T>(), T>> JClass::getField(
     const char* name,
     const char* descriptor) const {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   auto field = env->GetFieldID(self(), name, descriptor);
   FACEBOOK_JNI_THROW_EXCEPTION_IF(!field);
   return JField<T>{field};
@@ -260,7 +271,7 @@ template<typename T>
 inline JStaticField<enable_if_t<IsJniScalar<T>(), T>> JClass::getStaticField(
     const char* name,
     const char* descriptor) const {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   auto field = env->GetStaticFieldID(self(), name, descriptor);
   FACEBOOK_JNI_THROW_EXCEPTION_IF(!field);
   return JStaticField<T>{field};
@@ -281,11 +292,16 @@ inline void JClass::setStaticFieldValue(JStaticField<T> field, T value) noexcept
   field.set(self(), value);
 }
 
+template<typename T, typename>
+inline void JClass::setStaticFieldValue(JStaticField<T> field, alias_ref<T> value) noexcept {
+  setStaticFieldValue(field, value.get());
+}
+
 template<typename R, typename... Args>
 inline local_ref<R> JClass::newObject(
     JConstructor<R(Args...)> constructor,
     Args... args) const {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   auto object = env->NewObject(self(), constructor.getId(),
       detail::callToJni(
         detail::Convert<typename std::decay<Args>::type>::toCall(args))...);
@@ -338,18 +354,11 @@ struct Convert<const char*> {
 };
 }
 
-// jthrowable //////////////////////////////////////////////////////////////////////////////////////
-
-inline local_ref<JThrowable> JThrowable::initCause(alias_ref<JThrowable> cause) {
-  static auto meth = javaClassStatic()->getMethod<javaobject(javaobject)>("initCause");
-  return meth(self(), cause.get());
-}
-
 // jtypeArray //////////////////////////////////////////////////////////////////////////////////////
 
 namespace detail {
 inline size_t JArray::size() const noexcept {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   return env->GetArrayLength(self());
 }
 }
@@ -409,8 +418,8 @@ std::string JArrayClass<T>::get_instantiated_base_name() {
 
 template<typename T>
 auto JArrayClass<T>::newArray(size_t size) -> local_ref<javaobject> {
-  static auto elementClass = findClassStatic(jtype_traits<T>::base_name().c_str());
+  static const auto elementClass = findClassStatic(jtype_traits<T>::base_name().c_str());
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   auto rawArray = env->NewObjectArray(size, elementClass.get(), nullptr);
   FACEBOOK_JNI_THROW_EXCEPTION_IF(!rawArray);
   return adopt_local(static_cast<javaobject>(rawArray));
@@ -418,13 +427,13 @@ auto JArrayClass<T>::newArray(size_t size) -> local_ref<javaobject> {
 
 template<typename T>
 inline void JArrayClass<T>::setElement(size_t idx, const T& value) {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   env->SetObjectArrayElement(this->self(), idx, value);
 }
 
 template<typename T>
 inline local_ref<T> JArrayClass<T>::getElement(size_t idx) {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   auto rawElement = env->GetObjectArrayElement(this->self(), idx);
   return adopt_local(static_cast<T>(rawElement));
 }
@@ -434,12 +443,16 @@ inline detail::ElementProxy<JArrayClass<T>> JArrayClass<T>::operator[](size_t in
   return detail::ElementProxy<JArrayClass<T>>(this, index);
 }
 
+template<typename T>
+local_ref<typename JArrayClass<T>::javaobject> adopt_local_array(jobjectArray ref) {
+  return adopt_local(static_cast<typename JArrayClass<T>::javaobject>(ref));
+}
+
 // jarray /////////////////////////////////////////////////////////////////////////////////////////
 
 template <typename JArrayType>
 auto JPrimitiveArray<JArrayType>::getRegion(jsize start, jsize length)
     -> std::unique_ptr<T[]> {
-  using T = typename jtype_traits<JArrayType>::entry_type;
   auto buf = std::unique_ptr<T[]>{new T[length]};
   getRegion(start, length, buf.get());
   return buf;
@@ -510,7 +523,7 @@ class PinnedCriticalAlloc {
       jboolean* isCopy) {
     (void)start;
     (void)length;
-    const auto env = internal::getEnv();
+    const auto env = Environment::current();
     *elements = static_cast<T*>(env->GetPrimitiveArrayCritical(array.get(), isCopy));
     FACEBOOK_JNI_THROW_EXCEPTION_IF(!elements);
     *size = array->size();
@@ -523,7 +536,7 @@ class PinnedCriticalAlloc {
       jint mode) {
     (void)start;
     (void)size;
-    const auto env = internal::getEnv();
+    const auto env = Environment::current();
     env->ReleasePrimitiveArrayCritical(array.get(), elements, mode);
   }
 };

lib/fb/src/main/cpp/include/fbjni/detail/CoreClasses.h

@@ -20,14 +20,19 @@
 
 #include <jni.h>
 
-#include <fb/visibility.h>
-
 namespace facebook {
 namespace jni {
 
 class JClass;
 class JObject;
 
+namespace detail {
+
+/// Lookup a class by name.  This should only be used internally.
+jclass findClass(JNIEnv* env, const char* name);
+
+}
+
 /// Lookup a class by name. Note this functions returns an alias_ref that
 /// points to a leaked global reference.  This is appropriate for classes
 /// that are never unloaded (which is any class in an Android app and most
@@ -37,7 +42,7 @@ class JObject;
 /// in a "static auto" variable, or a static global.
 ///
 /// @return Returns a leaked global reference to the class
-FBEXPORT alias_ref<JClass> findClassStatic(const char* name);
+alias_ref<JClass> findClassStatic(const char* name);
 
 /// Lookup a class by name. Note this functions returns a local reference,
 /// which means that it must not be stored in a static variable.
@@ -46,12 +51,12 @@ FBEXPORT alias_ref<JClass> findClassStatic(const char* name);
 /// (like caching method ids).
 ///
 /// @return Returns a global reference to the class
-FBEXPORT local_ref<JClass> findClassLocal(const char* name);
+local_ref<JClass> findClassLocal(const char* name);
 
 /// Check to see if two references refer to the same object. Comparison with nullptr
 /// returns true if and only if compared to another nullptr. A weak reference that
 /// refers to a reclaimed object count as nullptr.
-FBEXPORT bool isSameObject(alias_ref<JObject> lhs, alias_ref<JObject> rhs) noexcept;
+bool isSameObject(alias_ref<JObject> lhs, alias_ref<JObject> rhs) noexcept;
 
 // Together, these classes allow convenient use of any class with the fbjni
 // helpers.  To use:
@@ -70,7 +75,7 @@ FBEXPORT bool isSameObject(alias_ref<JObject> lhs, alias_ref<JObject> rhs) noexc
 //   constexpr static auto kJavaDescriptor = "Lcom/example/package/MyClass;";
 //
 //   void foo() {
-//     static auto method = javaClassStatic()->getMethod<void()>("foo");
+//     static const auto method = javaClassStatic()->getMethod<void()>("foo");
 //     method(self());
 //   }
 //
@@ -94,7 +99,7 @@ static local_ref<JC> newInstance(Args... args);
 
 class MonitorLock;
 
-class FBEXPORT JObject : detail::JObjectBase {
+class JObject : detail::JObjectBase {
 public:
   static constexpr auto kJavaDescriptor = "Ljava/lang/Object;";
 
@@ -115,10 +120,12 @@ public:
   template<typename T>
   local_ref<T*> getFieldValue(JField<T*> field) const noexcept;
 
-  /// Set the value of field. Any Java type is accepted, including the primitive types
+  /// Set the value of field. Any Java type is accepted.
-  /// and raw reference types.
   template<typename T>
   void setFieldValue(JField<T> field, T value) noexcept;
+  template<typename T,
+           typename = typename std::enable_if<IsPlainJniReference<T>(), T>::type>
+  void setFieldValue(JField<T> field, alias_ref<T> value) noexcept;
 
   /// Convenience method to create a std::string representing the object
   std::string toString() const;
@@ -190,7 +197,7 @@ struct JTypeFor<T, Base, void> {
 // jthrowable) to be used as javaobject. This should only be necessary for
 // built-in jni types and not user-defined ones.
 template <typename T, typename Base = JObject, typename JType = void>
-class FBEXPORT JavaClass : public Base {
+class JavaClass : public Base {
   using JObjType = typename detail::JTypeFor<T, Base, JType>;
 public:
   using _javaobject = typename JObjType::_javaobject;
@@ -218,7 +225,7 @@ protected:
 /// Wrapper to provide functionality to jclass references
 struct NativeMethod;
 
-class FBEXPORT JClass : public JavaClass<JClass, JObject, jclass> {
+class JClass : public JavaClass<JClass, JObject, jclass> {
  public:
   /// Java type descriptor
   static constexpr const char* kJavaDescriptor = "Ljava/lang/Class;";
@@ -295,10 +302,12 @@ class FBEXPORT JClass : public JavaClass<JClass, JObject, jclass> {
   template<typename T>
   local_ref<T*> getStaticFieldValue(JStaticField<T*> field) noexcept;
 
-  /// Set the value of field. Any Java type is accepted, including the primitive types
+  /// Set the value of field. Any Java type is accepted.
-  /// and raw reference types.
   template<typename T>
   void setStaticFieldValue(JStaticField<T> field, T value) noexcept;
+  template<typename T,
+           typename = typename std::enable_if<IsPlainJniReference<T>(), T>::type>
+  void setStaticFieldValue(JStaticField<T> field, alias_ref<T> value) noexcept;
 
   /// Allocates a new object and invokes the specified constructor
   template<typename R, typename... Args>
@@ -330,27 +339,23 @@ private:
 void registerNatives(const char* name, std::initializer_list<NativeMethod> methods);
 
 /// Wrapper to provide functionality to jstring references
-class FBEXPORT JString : public JavaClass<JString, JObject, jstring> {
+class JString : public JavaClass<JString, JObject, jstring> {
  public:
   /// Java type descriptor
   static constexpr const char* kJavaDescriptor = "Ljava/lang/String;";
 
   /// Convenience method to convert a jstring object to a std::string
   std::string toStdString() const;
+
+  /// Convenience method to convert a jstring object to a std::u16string
+  std::u16string toU16String() const;
 };
 
-/// Convenience functions to convert a std::string or const char* into a @ref local_ref to a
+/// Convenience functions to convert a const char*, std::string, or std::u16string
-/// jstring
+/// into a @ref local_ref to a jstring.
-FBEXPORT local_ref<JString> make_jstring(const char* modifiedUtf8);
+local_ref<JString> make_jstring(const char* modifiedUtf8);
-FBEXPORT local_ref<JString> make_jstring(const std::string& modifiedUtf8);
+local_ref<JString> make_jstring(const std::string& modifiedUtf8);
-
+local_ref<JString> make_jstring(const std::u16string& utf16);
-/// Wrapper to provide functionality to jthrowable references
-class FBEXPORT JThrowable : public JavaClass<JThrowable, JObject, jthrowable> {
- public:
-  static constexpr const char* kJavaDescriptor = "Ljava/lang/Throwable;";
-
-  local_ref<JThrowable> initCause(alias_ref<JThrowable> cause);
-};
 
 namespace detail {
 template<typename Target>
@@ -378,7 +383,7 @@ class ElementProxy {
 }
 
 namespace detail {
-class FBEXPORT JArray : public JavaClass<JArray, JObject, jarray> {
+class JArray : public JavaClass<JArray, JObject, jarray> {
  public:
   // This cannot be used in a scope that derives a descriptor (like in a method
   // signature). Use a more derived type instead (like JArrayInt or
@@ -390,7 +395,7 @@ class FBEXPORT JArray : public JavaClass<JArray, JObject, jarray> {
 // This is used so that the JArrayClass<T> javaobject extends jni's
 // jobjectArray. This class should not be used directly. A general Object[]
 // should use JArrayClass<jobject>.
-class FBEXPORT JTypeArray : public JavaClass<JTypeArray, JArray, jobjectArray> {
+class JTypeArray : public JavaClass<JTypeArray, JArray, jobjectArray> {
   // This cannot be used in a scope that derives a descriptor (like in a method
   // signature).
   static constexpr const char* kJavaDescriptor = nullptr;
@@ -440,9 +445,7 @@ template <typename T>
 using jtypeArray = typename JArrayClass<T>::javaobject;
 
 template<typename T>
-local_ref<typename JArrayClass<T>::javaobject> adopt_local_array(jobjectArray ref) {
+local_ref<typename JArrayClass<T>::javaobject> adopt_local_array(jobjectArray ref);
-  return adopt_local(static_cast<typename JArrayClass<T>::javaobject>(ref));
-}
 
 template<typename Target>
 local_ref<typename Target::javaentry> adopt_local(detail::ElementProxy<Target> elementProxy) {
@@ -460,7 +463,7 @@ template <typename T> class PinnedCriticalAlloc;
 /// This is an empty holder by itself. Construct a PinnedPrimitiveArray to actually interact with
 /// the elements of the array.
 template <typename JArrayType>
-class FBEXPORT JPrimitiveArray :
+class JPrimitiveArray :
     public JavaClass<JPrimitiveArray<JArrayType>, detail::JArray, JArrayType> {
   static_assert(is_jni_primitive_array<JArrayType>(), "");
  public:
@@ -500,14 +503,14 @@ private:
   void releaseElements(T* elements, jint mode);
 };
 
-FBEXPORT local_ref<jbooleanArray> make_boolean_array(jsize size);
+local_ref<jbooleanArray> make_boolean_array(jsize size);
-FBEXPORT local_ref<jbyteArray> make_byte_array(jsize size);
+local_ref<jbyteArray> make_byte_array(jsize size);
-FBEXPORT local_ref<jcharArray> make_char_array(jsize size);
+local_ref<jcharArray> make_char_array(jsize size);
-FBEXPORT local_ref<jshortArray> make_short_array(jsize size);
+local_ref<jshortArray> make_short_array(jsize size);
-FBEXPORT local_ref<jintArray> make_int_array(jsize size);
+local_ref<jintArray> make_int_array(jsize size);
-FBEXPORT local_ref<jlongArray> make_long_array(jsize size);
+local_ref<jlongArray> make_long_array(jsize size);
-FBEXPORT local_ref<jfloatArray> make_float_array(jsize size);
+local_ref<jfloatArray> make_float_array(jsize size);
-FBEXPORT local_ref<jdoubleArray> make_double_array(jsize size);
+local_ref<jdoubleArray> make_double_array(jsize size);
 
 using JArrayBoolean = JPrimitiveArray<jbooleanArray>;
 using JArrayByte = JPrimitiveArray<jbyteArray>;
@@ -569,6 +572,29 @@ class PinnedPrimitiveArray {
    friend class JPrimitiveArray<typename jtype_traits<T>::array_type>;
 };
 
+struct JStackTraceElement : JavaClass<JStackTraceElement> {
+  static auto constexpr kJavaDescriptor = "Ljava/lang/StackTraceElement;";
+
+  static local_ref<javaobject> create(const std::string& declaringClass, const std::string& methodName, const std::string& file, int line);
+
+  std::string getClassName() const;
+  std::string getMethodName() const;
+  std::string getFileName() const;
+  int getLineNumber() const;
+};
+
+/// Wrapper to provide functionality to jthrowable references
+class JThrowable : public JavaClass<JThrowable, JObject, jthrowable> {
+ public:
+  static constexpr const char* kJavaDescriptor = "Ljava/lang/Throwable;";
+
+  using JStackTrace = JArrayClass<JStackTraceElement::javaobject>;
+
+  local_ref<JThrowable> initCause(alias_ref<JThrowable> cause);
+  local_ref<JStackTrace> getStackTrace();
+  void setStackTrace(alias_ref<JArrayClass<JStackTraceElement::javaobject>>);
+};
+
 #pragma push_macro("PlainJniRefMap")
 #undef PlainJniRefMap
 #define PlainJniRefMap(rtype, jtype) \

lib/fb/src/main/cpp/include/fbjni/detail/Environment.h

@@ -9,24 +9,69 @@
 #include <string>
 #include <jni.h>
 
-#include <fb/visibility.h>
 
 namespace facebook {
 namespace jni {
 
 // Keeps a thread-local reference to the current thread's JNIEnv.
 struct Environment {
-  // May be null if this thread isn't attached to the JVM
+  // Throws a std::runtime_error if this thread isn't attached to the JVM
-  FBEXPORT static JNIEnv* current();
+  // TODO(T6594868) Benchmark against raw JNI access
+  static JNIEnv* current();
   static void initialize(JavaVM* vm);
 
   // There are subtle issues with calling the next functions directly. It is
   // much better to always use a ThreadScope to manage attaching/detaching for
   // you.
-  FBEXPORT static JNIEnv* ensureCurrentThreadIsAttached();
+  static JNIEnv* ensureCurrentThreadIsAttached();
-  FBEXPORT static void detachCurrentThread();
 };
 
+namespace detail {
+
+// This will return null the thread isn't attached to the VM, or if
+// fbjni has never been initialized with a VM at all.  You probably
+// shouldn't be using this.
+JNIEnv* currentOrNull();
+
+/**
+ * If there's thread-local data, it's a pointer to one of these.  The
+ * instance is a member of JniEnvCacher or ThreadScope, and lives on
+ * the stack.
+ */
+struct TLData {
+  // This is modified only by JniEnvCacher, and is guaranteed to be
+  // valid if set, and refer to an env which originated from a JNI
+  // call into C++.
+  JNIEnv* env;
+  // This is modified only by ThreadScope, and is set only if an
+  // instance of ThreadScope which attached is on the stack.
+  bool attached;
+};
+
+/**
+ * RAII object which manages a cached JNIEnv* value.  A Value is only
+ * cached if it is guaranteed safe, which means when C++ is called
+ * from a registered fbjni function.
+ */
+class JniEnvCacher {
+public:
+  JniEnvCacher(JNIEnv* env);
+  JniEnvCacher(JniEnvCacher&) = delete;
+  JniEnvCacher(JniEnvCacher&&) = default;
+  JniEnvCacher& operator=(JniEnvCacher&) = delete;
+  JniEnvCacher& operator=(JniEnvCacher&&) = delete;
+  ~JniEnvCacher();
+
+private:
+  // If this flag is set, then, this object needs to clear the cache.
+  bool thisCached_;
+
+  // The thread local pointer may point here.
+  detail::TLData data_;
+};
+
+}
+
 /**
  * RAII Object that attaches a thread to the JVM. Failing to detach from a thread before it
  * exits will cause a crash, as will calling Detach an extra time, and this guard class helps
@@ -48,8 +93,11 @@ struct Environment {
  *    class or instance to the new thread; this bypasses the need for the class loader.
  *    (See http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/invocation.html#attach_current_thread)
  *    If you need access to the application's classes, you can use ThreadScope::WithClassLoader.
+ *  - If fbjni has never been initialized, there will be no JavaVM object to attach with.
+ *    In that case, a std::runtime_error will be thrown.  This is only likely to happen in a
+ *    standalone C++ application, or if Environment::initialize is not used.
  */
-class FBEXPORT ThreadScope {
+class ThreadScope {
  public:
   ThreadScope();
   ThreadScope(ThreadScope&) = delete;
@@ -67,8 +115,14 @@ class FBEXPORT ThreadScope {
   static void WithClassLoader(std::function<void()>&& runnable);
 
   static void OnLoad();
+
  private:
-  bool attachedWithThisScope_;
+  // If this flag is set, then this object needs to detach.
+  bool thisAttached_;
+
+  // The thread local pointer may point here.
+  detail::TLData data_;
 };
+
 }
 }

lib/fb/src/main/cpp/include/fbjni/detail/Exceptions.h

@@ -23,12 +23,15 @@
 
 #include <jni.h>
 
-#include <fb/visibility.h>
-
 #include "Common.h"
 #include "References.h"
 #include "CoreClasses.h"
 
+#if defined(__ANDROID__) && defined(__ARM_ARCH_5TE__) && !defined(FBJNI_NO_EXCEPTION_PTR)
+// ARMv5 NDK does not support exception_ptr so we cannot use that when building for it.
+#define FBJNI_NO_EXCEPTION_PTR
+#endif
+
 namespace facebook {
 namespace jni {
 
@@ -57,10 +60,10 @@ class JCppException : public JavaClass<JCppException, JThrowable> {
  *
  * Note: the what() method of this class is not thread-safe (t6900503).
  */
-class FBEXPORT JniException : public std::exception {
+class JniException : public std::exception {
  public:
   JniException();
-  ~JniException();
+  ~JniException() override;
 
   explicit JniException(alias_ref<jthrowable> throwable);
 
@@ -70,7 +73,7 @@ class FBEXPORT JniException : public std::exception {
 
   local_ref<JThrowable> getThrowable() const noexcept;
 
-  virtual const char* what() const noexcept;
+  const char* what() const noexcept override;
 
   void setJavaException() const noexcept;
 
@@ -105,11 +108,23 @@ template<typename... Args>
 }
 
 // Identifies any pending C++ exception and throws it as a Java exception. If the exception can't
-// be thrown, it aborts the program. This is a noexcept function at C++ level.
+// be thrown, it aborts the program.
-FBEXPORT void translatePendingCppExceptionToJavaException() noexcept;
+void translatePendingCppExceptionToJavaException();
+
+#ifndef FBJNI_NO_EXCEPTION_PTR
+local_ref<JThrowable> getJavaExceptionForCppException(std::exception_ptr ptr);
+#endif
+
+/***
+ * The stack returned may include build ids.  It may be beneficial to
+ * call lyra::setLibraryIdentifierFunction before calling this if
+ * build ids are desirable.
+ */
+local_ref<JThrowable> getJavaExceptionForCppBackTrace();
+
+local_ref<JThrowable> getJavaExceptionForCppBackTrace(const char* msg);
 
 // For convenience, some exception names in java.lang are available here.
-
 const char* const gJavaLangIllegalArgumentException = "java/lang/IllegalArgumentException";
 
 }}

lib/fb/src/main/cpp/include/fbjni/detail/Hybrid.h

@@ -9,9 +9,6 @@
 #include <memory>
 #include <type_traits>
 
-#include <fb/assert.h>
-#include <fb/visibility.h>
-
 #include "CoreClasses.h"
 
 namespace facebook {
@@ -24,13 +21,45 @@ public:
   virtual ~BaseHybridClass() {}
 };
 
-struct FBEXPORT HybridData : public JavaClass<HybridData> {
+struct HybridData : public JavaClass<HybridData> {
   constexpr static auto kJavaDescriptor = "Lcom/facebook/jni/HybridData;";
-  void setNativePointer(std::unique_ptr<BaseHybridClass> new_value);
-  BaseHybridClass* getNativePointer();
   static local_ref<HybridData> create();
 };
 
+class HybridDestructor : public JavaClass<HybridDestructor> {
+  public:
+    static auto constexpr kJavaDescriptor = "Lcom/facebook/jni/HybridData$Destructor;";
+
+  detail::BaseHybridClass* getNativePointer();
+
+  void setNativePointer(std::unique_ptr<detail::BaseHybridClass> new_value);
+};
+
+template<typename T>
+detail::BaseHybridClass* getNativePointer(T t) {
+  return getHolder(t)->getNativePointer();
+}
+
+template<typename T>
+void setNativePointer(T t, std::unique_ptr<detail::BaseHybridClass> new_value) {
+  getHolder(t)->setNativePointer(std::move(new_value));
+}
+
+template<typename T>
+local_ref<HybridDestructor> getHolder(T t) {
+  static auto holderField = t->getClass()->template getField<HybridDestructor::javaobject>("mDestructor");
+  return t->getFieldValue(holderField);
+}
+
+// JavaClass for HybridClassBase
+struct HybridClassBase : public JavaClass<HybridClassBase> {
+  constexpr static auto kJavaDescriptor = "Lcom/facebook/jni/HybridClassBase;";
+
+  static bool isHybridClassBase(alias_ref<jclass> jclass) {
+    return HybridClassBase::javaClassStatic()->isAssignableFrom(jclass);
+  }
+};
+
 template <typename Base, typename Enabled = void>
 struct HybridTraits {
   // This static assert should actually always fail if we don't use one of the
@@ -65,7 +94,7 @@ struct HybridTraits<
 
 // convert to HybridClass* from jhybridobject
 template <typename T>
-struct FBEXPORT Convert<
+struct Convert<
   T, typename std::enable_if<
     std::is_base_of<BaseHybridClass, typename std::remove_pointer<T>::type>::value>::type> {
   typedef typename std::remove_pointer<T>::type::jhybridobject jniType;
@@ -90,7 +119,7 @@ struct RefReprType<T, typename std::enable_if<std::is_base_of<BaseHybridClass, T
 }
 
 template <typename T, typename Base = detail::BaseHybridClass>
-class FBEXPORT HybridClass : public detail::HybridTraits<Base>::CxxBase {
+class HybridClass : public detail::HybridTraits<Base>::CxxBase {
 public:
   struct JavaPart : JavaClass<JavaPart, typename detail::HybridTraits<Base>::JavaBase> {
     // At this point, T is incomplete, and so we cannot access
@@ -107,6 +136,7 @@ public:
     T* cthis();
 
     friend class HybridClass;
+    friend T;
   };
 
   using jhybridobject = typename JavaPart::javaobject;
@@ -136,7 +166,7 @@ protected:
 
   static local_ref<detail::HybridData> makeHybridData(std::unique_ptr<T> cxxPart) {
     auto hybridData = detail::HybridData::create();
-    hybridData->setNativePointer(std::move(cxxPart));
+    setNativePointer(hybridData, std::move(cxxPart));
     return hybridData;
   }
 
@@ -145,6 +175,11 @@ protected:
     return makeHybridData(std::unique_ptr<T>(new T(std::forward<Args>(args)...)));
   }
 
+  template <typename... Args>
+  static void setCxxInstance(alias_ref<jhybridobject> o, Args&&... args) {
+    setNativePointer(o, std::unique_ptr<T>(new T(std::forward<Args>(args)...)));
+  }
+
 public:
   // Factory method for creating a hybrid object where the arguments
   // are used to initialize the C++ part directly without passing them
@@ -158,8 +193,20 @@ public:
   // C++ object fails, or any JNI methods throw.
   template <typename... Args>
   static local_ref<JavaPart> newObjectCxxArgs(Args&&... args) {
-    auto hybridData = makeCxxInstance(std::forward<Args>(args)...);
+    static bool isHybrid = detail::HybridClassBase::isHybridClassBase(javaClassStatic());
-    return JavaPart::newInstance(hybridData);
+    auto cxxPart = std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+
+    local_ref<JavaPart> result;
+    if (isHybrid) {
+      result = JavaPart::newInstance();
+      setNativePointer(result, std::move(cxxPart));
+    }
+    else {
+      auto hybridData = makeHybridData(std::move(cxxPart));
+      result = JavaPart::newInstance(hybridData);
+    }
+
+    return result;
   }
 
  // TODO? Create reusable interface for Allocatable classes and use it to
@@ -194,17 +241,23 @@ public:
 
 template <typename T, typename B>
 inline T* HybridClass<T, B>::JavaPart::cthis() {
+  detail::BaseHybridClass* result = 0;
+  static bool isHybrid = detail::HybridClassBase::isHybridClassBase(this->getClass());
+  if (isHybrid) {
+    result = getNativePointer(this);
+  } else {
     static auto field =
       HybridClass<T, B>::JavaPart::javaClassStatic()->template getField<detail::HybridData::javaobject>("mHybridData");
     auto hybridData = this->getFieldValue(field);
     if (!hybridData) {
       throwNewJavaException("java/lang/NullPointerException", "java.lang.NullPointerException");
     }
+
+    result = getNativePointer(hybridData);
+  }
+
   // I'd like to use dynamic_cast here, but -fno-rtti is the default.
-  T* value = static_cast<T*>(hybridData->getNativePointer());
+  return static_cast<T*>(result);
-  // This would require some serious programmer error.
-  FBASSERTMSGF(value != 0, "Incorrect C++ type in hybrid field");
-  return value;
 };
 
 template <typename T, typename B>

lib/fb/src/main/cpp/include/fbjni/detail/Iterator-inl.h

@@ -32,7 +32,7 @@ struct IteratorHelper : public JavaClass<IteratorHelper<E>> {
   value_type next() {
     static auto elementField =
       JavaBase_::javaClassStatic()->template getField<jobject>("mElement");
-    return dynamic_ref_cast<E>(JavaBase_::getFieldValue(elementField));
+    return dynamic_ref_cast<JniType<E>>(JavaBase_::getFieldValue(elementField));
   }
 
   static void reset(value_type& v) {

lib/fb/src/main/cpp/include/fbjni/detail/JWeakReference.h

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#pragma once
+
+#include "CoreClasses.h"
+
+namespace facebook {
+namespace jni {
+
+/**
+ * Wrap Java's WeakReference instead of using JNI WeakGlobalRefs.
+ * A WeakGlobalRef can yield a strong reference even after the object has been
+  * finalized. See comment in the djinni library.
+ * https://github.com/dropbox/djinni/blob/master/support-lib/jni/djinni_support.hpp
+ */
+template<typename T = jobject>
+class JWeakReference : public JavaClass<JWeakReference<T>> {
+
+ typedef JavaClass<JWeakReference<T>> JavaBase_;
+
+ public:
+  static constexpr const char* kJavaDescriptor = "Ljava/lang/ref/WeakReference;";
+
+  static local_ref<JWeakReference<T>> newInstance(alias_ref<T> object) {
+    return JavaBase_::newInstance(static_ref_cast<jobject>(object));
+  }
+
+  local_ref<T> get() const {
+    static const auto method = JavaBase_::javaClassStatic()->template getMethod<jobject()>("get");
+    return static_ref_cast<T>(method(JavaBase_::self()));
+  }
+};
+
+}
+}

lib/fb/src/main/cpp/include/fbjni/detail/Log.h

@@ -0,0 +1,67 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+/** @file ALog.h
+ *
+ *  Very simple (android only) logging. Define LOG_TAG to enable the macros.
+ */
+
+#pragma once
+
+#ifdef __ANDROID__
+
+#include <android/log.h>
+
+namespace facebook {
+namespace jni {
+namespace log_ {
+// the weird name of this namespace is to avoid a conflict with the
+// function named log.
+
+inline void loge(const char* tag, const char* msg) noexcept {
+  __android_log_write(ANDROID_LOG_ERROR, tag, msg);
+}
+
+template<typename... ARGS>
+inline void loge(const char* tag, const char* msg, ARGS... args) noexcept {
+  __android_log_print(ANDROID_LOG_ERROR, tag, msg, args...);
+}
+
+inline void logf(const char* tag, const char* msg) noexcept {
+  __android_log_write(ANDROID_LOG_FATAL, tag, msg);
+}
+
+template<typename... ARGS>
+inline void logf(const char* tag, const char* msg, ARGS... args) noexcept {
+  __android_log_print(ANDROID_LOG_FATAL, tag, msg, args...);
+}
+
+template<typename... ARGS>
+[[noreturn]]
+inline void logassert(const char* tag, const char* msg, ARGS... args) noexcept {
+  __android_log_assert(0, tag, msg, args...);
+}
+
+
+#ifdef LOG_TAG
+# define FBJNI_LOGE(...) ::facebook::jni::log_::loge(LOG_TAG, __VA_ARGS__)
+# define FBJNI_LOGF(...) ::facebook::jni::log_::logf(LOG_TAG, __VA_ARGS__)
+# define FBJNI_ASSERT(cond) do { if (!(cond)) ::facebook::jni::log_::logassert(LOG_TAG, "%s", #cond); } while(0)
+#else
+# define FBJNI_LOGE(...) ::facebook::jni::log_::loge("log", __VA_ARGS__)
+# define FBJNI_LOGF(...) ::facebook::jni::log_::logf("log", __VA_ARGS__)
+# define FBJNI_ASSERT(cond) do { if (!(cond)) ::facebook::jni::log_::logassert("log", "%s", #cond); } while(0)
+#endif
+
+}}}
+
+#else
+#include <stdlib.h>
+
+# define FBJNI_LOGE(...) ((void)0)
+# define FBJNI_LOGF(...) (abort())
+# define FBJNI_ASSERT(cond) ((void)0)
+#endif

lib/fb/src/main/cpp/include/fbjni/detail/Meta-inl.h

@@ -14,10 +14,6 @@
 #include "References.h"
 #include "Boxed.h"
 
-#if defined(__ANDROID__)
-#include <sys/system_properties.h>
-#endif
-
 namespace facebook {
 namespace jni {
 
@@ -63,31 +59,10 @@ local_ref<JArrayClass<jobject>::javaobject> makeArgsArray(Args... args) {
   return arr;
 }
 
-
-inline bool needsSlowPath(alias_ref<jobject> obj) {
-#if defined(__ANDROID__)
-  // On Android 6.0, art crashes when attempting to call a function on a Proxy.
-  // So, when we detect that case we must use the safe, slow workaround. That is,
-  // we resolve the method id to the corresponding java.lang.reflect.Method object
-  // and make the call via it's invoke() method.
-  static auto android_sdk = ([] {
-     char sdk_version_str[PROP_VALUE_MAX];
-     __system_property_get("ro.build.version.sdk", sdk_version_str);
-     return atoi(sdk_version_str);
-  })();
-  static auto is_bad_android = android_sdk == 23;
-  if (!is_bad_android) return false;
-  static auto proxy_class = findClassStatic("java/lang/reflect/Proxy");
-  return obj->isInstanceOf(proxy_class);
-#else
-  return false;
-#endif
-}
-
 }
 
 template<typename... Args>
-inline void JMethod<void(Args...)>::operator()(alias_ref<jobject> self, Args... args) {
+inline void JMethod<void(Args...)>::operator()(alias_ref<jobject> self, Args... args) const {
   const auto env = Environment::current();
   env->CallVoidMethod(
         self.get(),
@@ -98,10 +73,10 @@ inline void JMethod<void(Args...)>::operator()(alias_ref<jobject> self, Args...
 
 #pragma push_macro("DEFINE_PRIMITIVE_CALL")
 #undef DEFINE_PRIMITIVE_CALL
-#define DEFINE_PRIMITIVE_CALL(TYPE, METHOD, CLASS)                                             \
+#define DEFINE_PRIMITIVE_CALL(TYPE, METHOD)                                                    \
 template<typename... Args>                                                                     \
-inline TYPE JMethod<TYPE(Args...)>::operator()(alias_ref<jobject> self, Args... args) {        \
+inline TYPE JMethod<TYPE(Args...)>::operator()(alias_ref<jobject> self, Args... args) const {  \
-  const auto env = internal::getEnv();                                                         \
+  const auto env = Environment::current();                                                     \
   auto result = env->Call ## METHOD ## Method(                                                 \
         self.get(),                                                                            \
         getId(),                                                                               \
@@ -110,14 +85,14 @@ inline TYPE JMethod<TYPE(Args...)>::operator()(alias_ref<jobject> self, Args...
   return result;                                                                               \
 }
 
-DEFINE_PRIMITIVE_CALL(jboolean, Boolean, JBoolean)
+DEFINE_PRIMITIVE_CALL(jboolean, Boolean)
-DEFINE_PRIMITIVE_CALL(jbyte, Byte, JByte)
+DEFINE_PRIMITIVE_CALL(jbyte, Byte)
-DEFINE_PRIMITIVE_CALL(jchar, Char, JCharacter)
+DEFINE_PRIMITIVE_CALL(jchar, Char)
-DEFINE_PRIMITIVE_CALL(jshort, Short, JShort)
+DEFINE_PRIMITIVE_CALL(jshort, Short)
-DEFINE_PRIMITIVE_CALL(jint, Int, JInteger)
+DEFINE_PRIMITIVE_CALL(jint, Int)
-DEFINE_PRIMITIVE_CALL(jlong, Long, JLong)
+DEFINE_PRIMITIVE_CALL(jlong, Long)
-DEFINE_PRIMITIVE_CALL(jfloat, Float, JFloat)
+DEFINE_PRIMITIVE_CALL(jfloat, Float)
-DEFINE_PRIMITIVE_CALL(jdouble, Double, JDouble)
+DEFINE_PRIMITIVE_CALL(jdouble, Double)
 #pragma pop_macro("DEFINE_PRIMITIVE_CALL")
 
 /// JMethod specialization for references that wraps the return value in a @ref local_ref
@@ -132,13 +107,13 @@ class JMethod<R(Args...)> : public JMethodBase {
   JMethod(const JMethod& other) noexcept = default;
 
   /// Invoke a method and return a local reference wrapping the result
-  local_ref<JniRet> operator()(alias_ref<jobject> self, Args... args);
+  local_ref<JniRet> operator()(alias_ref<jobject> self, Args... args) const;
 
   friend class JClass;
 };
 
 template<typename R, typename... Args>
-inline auto JMethod<R(Args...)>::operator()(alias_ref<jobject> self, Args... args) -> local_ref<JniRet> {
+inline auto JMethod<R(Args...)>::operator()(alias_ref<jobject> self, Args... args) const -> local_ref<JniRet> {
   const auto env = Environment::current();
   auto result = env->CallObjectMethod(
       self.get(),
@@ -149,8 +124,8 @@ inline auto JMethod<R(Args...)>::operator()(alias_ref<jobject> self, Args... arg
 }
 
 template<typename... Args>
-inline void JStaticMethod<void(Args...)>::operator()(alias_ref<jclass> cls, Args... args) {
+inline void JStaticMethod<void(Args...)>::operator()(alias_ref<jclass> cls, Args... args) const {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   env->CallStaticVoidMethod(
         cls.get(),
         getId(),
@@ -162,8 +137,8 @@ inline void JStaticMethod<void(Args...)>::operator()(alias_ref<jclass> cls, Args
 #undef DEFINE_PRIMITIVE_STATIC_CALL
 #define DEFINE_PRIMITIVE_STATIC_CALL(TYPE, METHOD)                                             \
 template<typename... Args>                                                                     \
-inline TYPE JStaticMethod<TYPE(Args...)>::operator()(alias_ref<jclass> cls, Args... args) {    \
+inline TYPE JStaticMethod<TYPE(Args...)>::operator()(alias_ref<jclass> cls, Args... args) const { \
-  const auto env = internal::getEnv();                                                         \
+  const auto env = Environment::current();                                                         \
   auto result = env->CallStatic ## METHOD ## Method(                                           \
         cls.get(),                                                                             \
         getId(),                                                                               \
@@ -194,8 +169,8 @@ class JStaticMethod<R(Args...)> : public JMethodBase {
   JStaticMethod(const JStaticMethod& other) noexcept = default;
 
   /// Invoke a method and return a local reference wrapping the result
-  local_ref<JniRet> operator()(alias_ref<jclass> cls, Args... args) {
+  local_ref<JniRet> operator()(alias_ref<jclass> cls, Args... args) const {
-    const auto env = internal::getEnv();
+    const auto env = Environment::current();
     auto result = env->CallStaticObjectMethod(
           cls.get(),
           getId(),
@@ -209,8 +184,8 @@ class JStaticMethod<R(Args...)> : public JMethodBase {
 
 template<typename... Args>
 inline void
-JNonvirtualMethod<void(Args...)>::operator()(alias_ref<jobject> self, alias_ref<jclass> cls, Args... args) {
+JNonvirtualMethod<void(Args...)>::operator()(alias_ref<jobject> self, alias_ref<jclass> cls, Args... args) const {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   env->CallNonvirtualVoidMethod(
         self.get(),
         cls.get(),
@@ -224,8 +199,8 @@ JNonvirtualMethod<void(Args...)>::operator()(alias_ref<jobject> self, alias_ref<
 #define DEFINE_PRIMITIVE_NON_VIRTUAL_CALL(TYPE, METHOD)                                                      \
 template<typename... Args>                                                                                   \
 inline TYPE                                                                                                  \
-JNonvirtualMethod<TYPE(Args...)>::operator()(alias_ref<jobject> self, alias_ref<jclass> cls, Args... args) { \
+JNonvirtualMethod<TYPE(Args...)>::operator()(alias_ref<jobject> self, alias_ref<jclass> cls, Args... args) const { \
-  const auto env = internal::getEnv();                                                                       \
+  const auto env = Environment::current();                                                                   \
   auto result = env->CallNonvirtual ## METHOD ## Method(                                                     \
         self.get(),                                                                                          \
         cls.get(),                                                                                           \
@@ -256,8 +231,8 @@ class JNonvirtualMethod<R(Args...)> : public JMethodBase {
   JNonvirtualMethod(const JNonvirtualMethod& other) noexcept = default;
 
   /// Invoke a method and return a local reference wrapping the result
-  local_ref<JniRet> operator()(alias_ref<jobject> self, alias_ref<jclass> cls, Args... args){
+  local_ref<JniRet> operator()(alias_ref<jobject> self, alias_ref<jclass> cls, Args... args) const {
-    const auto env = internal::getEnv();
+    const auto env = Environment::current();
     auto result = env->CallNonvirtualObjectMethod(
           self.get(),
           cls.get(),
@@ -306,13 +281,13 @@ inline jfieldID JField<T>::getId() const noexcept {
 #define DEFINE_FIELD_PRIMITIVE_GET_SET(TYPE, METHOD)                 \
 template<>                                                           \
 inline TYPE JField<TYPE>::get(jobject object) const noexcept {       \
-  const auto env = internal::getEnv();                               \
+  const auto env = Environment::current();                           \
   return env->Get ## METHOD ## Field(object, field_id_);             \
 }                                                                    \
                                                                      \
 template<>                                                           \
 inline void JField<TYPE>::set(jobject object, TYPE value) noexcept { \
-  const auto env = internal::getEnv();                               \
+  const auto env = Environment::current();                           \
   env->Set ## METHOD ## Field(object, field_id_, value);             \
 }
 
@@ -328,12 +303,12 @@ DEFINE_FIELD_PRIMITIVE_GET_SET(jdouble, Double)
 
 template<typename T>
 inline T JField<T>::get(jobject object) const noexcept {
-  return static_cast<T>(internal::getEnv()->GetObjectField(object, field_id_));
+  return static_cast<T>(Environment::current()->GetObjectField(object, field_id_));
 }
 
 template<typename T>
 inline void JField<T>::set(jobject object, T value) noexcept {
-  internal::getEnv()->SetObjectField(object, field_id_, static_cast<jobject>(value));
+  Environment::current()->SetObjectField(object, field_id_, static_cast<jobject>(value));
 }
 
 // JStaticField<T> /////////////////////////////////////////////////////////////////////////////////
@@ -358,13 +333,13 @@ inline jfieldID JStaticField<T>::getId() const noexcept {
 #define DEFINE_STATIC_FIELD_PRIMITIVE_GET_SET(TYPE, METHOD)                \
 template<>                                                                 \
 inline TYPE JStaticField<TYPE>::get(jclass jcls) const noexcept {          \
-  const auto env = internal::getEnv();                                     \
+  const auto env = Environment::current();                                 \
   return env->GetStatic ## METHOD ## Field(jcls, field_id_);               \
 }                                                                          \
                                                                            \
 template<>                                                                 \
 inline void JStaticField<TYPE>::set(jclass jcls, TYPE value) noexcept {    \
-  const auto env = internal::getEnv();                                     \
+  const auto env = Environment::current();                                 \
   env->SetStatic ## METHOD ## Field(jcls, field_id_, value);               \
 }
 
@@ -380,13 +355,13 @@ DEFINE_STATIC_FIELD_PRIMITIVE_GET_SET(jdouble, Double)
 
 template<typename T>
 inline T JStaticField<T>::get(jclass jcls) const noexcept {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   return static_cast<T>(env->GetStaticObjectField(jcls, field_id_));
 }
 
 template<typename T>
 inline void JStaticField<T>::set(jclass jcls, T value) noexcept {
-  internal::getEnv()->SetStaticObjectField(jcls, field_id_, value);
+  Environment::current()->SetStaticObjectField(jcls, field_id_, value);
 }
 
 

lib/fb/src/main/cpp/include/fbjni/detail/Meta.h

@@ -80,7 +80,7 @@ class JMethod<TYPE(Args...)> : public JMethodBase {
   JMethod() noexcept {};                                                         \
   JMethod(const JMethod& other) noexcept = default;                              \
                                                                                  \
-  TYPE operator()(alias_ref<jobject> self, Args... args);                        \
+  TYPE operator()(alias_ref<jobject> self, Args... args) const;                  \
                                                                                  \
   friend class JClass;                                                           \
 }
@@ -130,7 +130,7 @@ class JStaticMethod<TYPE(Args...)> : public JMethodBase {                   \
   JStaticMethod() noexcept {};                                              \
   JStaticMethod(const JStaticMethod& other) noexcept = default;             \
                                                                             \
-  TYPE operator()(alias_ref<jclass> cls, Args... args);                     \
+  TYPE operator()(alias_ref<jclass> cls, Args... args) const;               \
                                                                             \
   friend class JClass;                                                      \
 }
@@ -170,7 +170,7 @@ class JNonvirtualMethod<TYPE(Args...)> : public JMethodBase {               \
   JNonvirtualMethod() noexcept {};                                          \
   JNonvirtualMethod(const JNonvirtualMethod& other) noexcept = default;     \
                                                                             \
-  TYPE operator()(alias_ref<jobject> self, alias_ref<jclass> cls, Args... args);       \
+  TYPE operator()(alias_ref<jobject> self, alias_ref<jclass> cls, Args... args) const; \
                                                                             \
   friend class JClass;                                                      \
 }

lib/fb/src/main/cpp/include/fbjni/detail/MetaConvert.h

@@ -66,6 +66,25 @@ struct Convert<bool> {
   }
 };
 
+// Sometimes (64-bit Android) jlong is "long long", but int64_t is "long".
+// Allow int64_t to work as jlong.
+template<typename T>
+struct Convert<T,
+    typename std::enable_if<
+      (std::is_same<T, long long>::value || std::is_same<T, int64_t>::value) && !std::is_same<T, jlong>::value
+    >::type> {
+  typedef jlong jniType;
+  static T fromJni(jniType t) {
+    return t;
+  }
+  static jniType toJniRet(T t) {
+    return t;
+  }
+  static jniType toCall(T t) {
+    return t;
+  }
+};
+
 // convert to alias_ref<T> from T
 template <typename T>
 struct Convert<alias_ref<T>> {
@@ -99,7 +118,21 @@ template <typename T>
 struct Convert<global_ref<T>> {
   typedef JniType<T> jniType;
   // No automatic synthesis of global_ref
-  static jniType toJniRet(global_ref<jniType> t) {
+  static jniType toJniRet(global_ref<jniType>&& t) {
+    // If this gets called, ownership the global_ref was passed in here.  (It's
+    // probably a copy of a persistent global_ref made when a function was
+    // declared to return a global_ref, but it could moved out or otherwise not
+    // referenced elsewhere.  Doesn't matter.)  Either way, the only safe way
+    // to return it is to make a local_ref, release it, and return the
+    // underlying local jobject.
+    auto ret = make_local(t);
+    return ret.release();
+  }
+  static jniType toJniRet(const global_ref<jniType>& t) {
+    // If this gets called, the function was declared to return const&.  We
+    // have a ref to a global_ref whose lifetime will exceed this call, so we
+    // can just get the underlying jobject and return it to java without
+    // needing to make a local_ref.
     return t.get();
   }
   static jniType toCall(global_ref<jniType> t) {

lib/fb/src/main/cpp/include/fbjni/detail/ReferenceAllocators-inl.h

@@ -10,6 +10,8 @@
 #include <new>
 #include <atomic>
 
+#include "Environment.h"
+
 namespace facebook {
 namespace jni {
 
@@ -18,7 +20,8 @@ namespace internal {
 
 // Statistics mostly provided for test (only updated if FBJNI_DEBUG_REFS is defined)
 struct ReferenceStats {
-  std::atomic_uint locals_deleted, globals_deleted, weaks_deleted;
+  std::atomic_uint locals_created, globals_created, weaks_created,
+                   locals_deleted, globals_deleted, weaks_deleted;
 
   void reset() noexcept;
 };
@@ -32,7 +35,10 @@ extern ReferenceStats g_reference_stats;
 
 inline jobject LocalReferenceAllocator::newReference(jobject original) const {
   internal::dbglog("Local new: %p", original);
-  auto ref = internal::getEnv()->NewLocalRef(original);
+  #ifdef FBJNI_DEBUG_REFS
+    ++internal::g_reference_stats.locals_created;
+  #endif
+  auto ref = Environment::current()->NewLocalRef(original);
   FACEBOOK_JNI_THROW_PENDING_EXCEPTION();
   return ref;
 }
@@ -45,15 +51,12 @@ inline void LocalReferenceAllocator::deleteReference(jobject reference) const no
       ++internal::g_reference_stats.locals_deleted;
     #endif
     assert(verifyReference(reference));
-    internal::getEnv()->DeleteLocalRef(reference);
+    Environment::current()->DeleteLocalRef(reference);
   }
 }
 
 inline bool LocalReferenceAllocator::verifyReference(jobject reference) const noexcept {
-  if (!reference || !internal::doesGetObjectRefTypeWork()) {
+  return isObjectRefType(reference, JNILocalRefType);
-    return true;
-  }
-  return internal::getEnv()->GetObjectRefType(reference) == JNILocalRefType;
 }
 
 
@@ -61,7 +64,10 @@ inline bool LocalReferenceAllocator::verifyReference(jobject reference) const no
 
 inline jobject GlobalReferenceAllocator::newReference(jobject original) const {
   internal::dbglog("Global new: %p", original);
-  auto ref = internal::getEnv()->NewGlobalRef(original);
+  #ifdef FBJNI_DEBUG_REFS
+    ++internal::g_reference_stats.globals_created;
+  #endif
+  auto ref = Environment::current()->NewGlobalRef(original);
   FACEBOOK_JNI_THROW_PENDING_EXCEPTION();
   return ref;
 }
@@ -74,15 +80,12 @@ inline void GlobalReferenceAllocator::deleteReference(jobject reference) const n
       ++internal::g_reference_stats.globals_deleted;
     #endif
     assert(verifyReference(reference));
-    internal::getEnv()->DeleteGlobalRef(reference);
+    Environment::current()->DeleteGlobalRef(reference);
   }
 }
 
 inline bool GlobalReferenceAllocator::verifyReference(jobject reference) const noexcept {
-  if (!reference || !internal::doesGetObjectRefTypeWork()) {
+  return isObjectRefType(reference, JNIGlobalRefType);
-    return true;
-  }
-  return internal::getEnv()->GetObjectRefType(reference) == JNIGlobalRefType;
 }
 
 
@@ -90,7 +93,10 @@ inline bool GlobalReferenceAllocator::verifyReference(jobject reference) const n
 
 inline jobject WeakGlobalReferenceAllocator::newReference(jobject original) const {
   internal::dbglog("Weak global new: %p", original);
-  auto ref = internal::getEnv()->NewWeakGlobalRef(original);
+  #ifdef FBJNI_DEBUG_REFS
+    ++internal::g_reference_stats.weaks_created;
+  #endif
+  auto ref = Environment::current()->NewWeakGlobalRef(original);
   FACEBOOK_JNI_THROW_PENDING_EXCEPTION();
   return ref;
 }
@@ -103,15 +109,12 @@ inline void WeakGlobalReferenceAllocator::deleteReference(jobject reference) con
       ++internal::g_reference_stats.weaks_deleted;
     #endif
     assert(verifyReference(reference));
-    internal::getEnv()->DeleteWeakGlobalRef(reference);
+    Environment::current()->DeleteWeakGlobalRef(reference);
   }
 }
 
 inline bool WeakGlobalReferenceAllocator::verifyReference(jobject reference) const noexcept {
-  if (!reference || !internal::doesGetObjectRefTypeWork()) {
+  return isObjectRefType(reference, JNIWeakGlobalRefType);
-    return true;
-  }
-  return internal::getEnv()->GetObjectRefType(reference) == JNIWeakGlobalRefType;
 }
 
 }}

lib/fb/src/main/cpp/include/fbjni/detail/ReferenceAllocators.h

@@ -13,14 +13,12 @@
 
 #pragma once
 
-#include <fb/visibility.h>
-
 #include "Common.h"
 
 namespace facebook { namespace jni {
 
 /// Allocator that handles local references
-class FBEXPORT LocalReferenceAllocator {
+class LocalReferenceAllocator {
  public:
   jobject newReference(jobject original) const;
   void deleteReference(jobject reference) const noexcept;
@@ -28,7 +26,7 @@ class FBEXPORT LocalReferenceAllocator {
 };
 
 /// Allocator that handles global references
-class FBEXPORT GlobalReferenceAllocator {
+class GlobalReferenceAllocator {
  public:
   jobject newReference(jobject original) const;
   void deleteReference(jobject reference) const noexcept;
@@ -36,23 +34,20 @@ class FBEXPORT GlobalReferenceAllocator {
 };
 
 /// Allocator that handles weak global references
-class FBEXPORT WeakGlobalReferenceAllocator {
+class WeakGlobalReferenceAllocator {
  public:
   jobject newReference(jobject original) const;
   void deleteReference(jobject reference) const noexcept;
   bool verifyReference(jobject reference) const noexcept;
 };
 
-/// @cond INTERNAL
-namespace internal {
-
 /**
- * @return true iff env->GetObjectRefType is expected to work properly.
+ * @return Helper based on GetObjectRefType.  Since this isn't defined
+ * on all versions of Java or Android, if the type can't be
+ * determined, this returns true.  If reference is nullptr, returns
+ * true.
  */
-FBEXPORT bool doesGetObjectRefTypeWork();
+bool isObjectRefType(jobject reference, jobjectRefType refType);
-
-}
-/// @endcond
 
 }}
 

lib/fb/src/main/cpp/include/fbjni/detail/References-inl.h

@@ -173,6 +173,29 @@ operator!=(const T1& a, const T2& b) {
   return !(a == b);
 }
 
+template<typename T1>
+inline enable_if_t<IsNonWeakReference<T1>(), bool>
+operator==(const T1& a, std::nullptr_t) {
+  return getPlainJniReference(a) == nullptr;
+}
+
+template<typename T1>
+inline enable_if_t<IsNonWeakReference<T1>(), bool>
+operator==(std::nullptr_t, const T1& a) {
+  return nullptr == getPlainJniReference(a);
+}
+
+template<typename T1>
+inline enable_if_t<IsNonWeakReference<T1>(), bool>
+operator!=(const T1& a, std::nullptr_t) {
+  return !(a == nullptr);
+}
+
+template<typename T1>
+inline enable_if_t<IsNonWeakReference<T1>(), bool>
+operator!=(std::nullptr_t, const T1& a) {
+  return !(nullptr == getPlainJniReference(a));
+}
 
 // base_owned_ref ///////////////////////////////////////////////////////////////////////
 
@@ -181,10 +204,11 @@ inline base_owned_ref<T, Alloc>::base_owned_ref() noexcept
   : base_owned_ref(nullptr)
 {}
 
-template <typename T, typename Alloc>
+template<typename T, typename Alloc>
-inline base_owned_ref<T, Alloc>::base_owned_ref(std::nullptr_t array) noexcept
+inline base_owned_ref<T, Alloc>::base_owned_ref(std::nullptr_t t) noexcept
-    : base_owned_ref(static_cast<javaobject>(nullptr)) {
+  : base_owned_ref(static_cast<javaobject>(nullptr))
-  (void)array;
+{
+  (void)t;
 }
 
 template<typename T, typename Alloc>
@@ -484,22 +508,25 @@ template<typename T, typename RefType>
 auto dynamic_ref_cast(const RefType& ref) ->
 enable_if_t<IsPlainJniReference<T>(), decltype(static_ref_cast<T>(ref))>
 {
-  if (! ref) {
+  if (!ref) {
     return decltype(static_ref_cast<T>(ref))();
   }
 
-  std::string target_class_name{jtype_traits<T>::base_name()};
+  static alias_ref<jclass> target_class = findClassStatic(jtype_traits<T>::base_name().c_str());
+  if (!target_class) {
+    throwNewJavaException("java/lang/ClassCastException",
+                          "Could not find class %s.",
+                          jtype_traits<T>::base_name().c_str());
 
-  // If not found, will throw an exception.
+  }
-  alias_ref<jclass> target_class = findClassStatic(target_class_name.c_str());
 
   local_ref<jclass> source_class = ref->getClass();
 
-  if ( ! source_class->isAssignableFrom(target_class)) {
+  if (!target_class->isAssignableFrom(source_class)) {
     throwNewJavaException("java/lang/ClassCastException",
                           "Tried to cast from %s to %s.",
                           source_class->toString().c_str(),
-                          target_class_name.c_str());
+                          jtype_traits<T>::base_name().c_str());
   }
 
   return static_ref_cast<T>(ref);

lib/fb/src/main/cpp/include/fbjni/detail/References.h

@@ -4,6 +4,7 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
+
 /** @file References.h
  *
  * Functionality similar to smart pointers, but for references into the VM. Four main reference
@@ -73,8 +74,6 @@
 
 #include <jni.h>
 
-#include <fb/visibility.h>
-
 #include "ReferenceAllocators.h"
 #include "TypeTraits.h"
 #include "References-forward.h"
@@ -250,6 +249,26 @@ template<typename T1, typename T2>
 enable_if_t<IsNonWeakReference<T1>() && IsNonWeakReference<T2>(), bool>
 operator!=(const T1& a, const T2& b);
 
+/**
+ * Compare references against nullptr
+ */
+template<typename T1>
+enable_if_t<IsNonWeakReference<T1>(), bool>
+operator==(const T1& a, std::nullptr_t);
+
+template<typename T1>
+enable_if_t<IsNonWeakReference<T1>(), bool>
+operator==(std::nullptr_t, const T1& a);
+
+template<typename T1>
+enable_if_t<IsNonWeakReference<T1>(), bool>
+operator!=(const T1& a, std::nullptr_t);
+
+template<typename T1>
+enable_if_t<IsNonWeakReference<T1>(), bool>
+operator!=(std::nullptr_t, const T1& a);
+
+
 template<typename T, typename Alloc>
 class base_owned_ref {
  public:
@@ -336,7 +355,7 @@ class weak_ref : public base_owned_ref<T, WeakGlobalReferenceAllocator> {
     : base_owned_ref<T, Allocator>{} {}
 
   /// Create a null reference
-  explicit weak_ref(std::nullptr_t) noexcept
+  /* implicit */ weak_ref(std::nullptr_t) noexcept
     : base_owned_ref<T, Allocator>{nullptr} {}
 
   /// Copy constructor (note creates a new reference)
@@ -405,7 +424,7 @@ class basic_strong_ref : public base_owned_ref<T, Alloc> {
     : base_owned_ref<T, Alloc>{} {}
 
   /// Create a null reference
-  explicit basic_strong_ref(std::nullptr_t) noexcept
+  /* implicit */ basic_strong_ref(std::nullptr_t) noexcept
     : base_owned_ref<T, Alloc>{nullptr} {}
 
   /// Copy constructor (note creates a new reference)
@@ -492,7 +511,7 @@ class alias_ref {
   alias_ref() noexcept;
 
   /// Create a null reference
-  alias_ref(std::nullptr_t) noexcept;
+  /* implicit */ alias_ref(std::nullptr_t) noexcept;
 
   /// Copy constructor
   alias_ref(const alias_ref& other) noexcept;
@@ -553,7 +572,7 @@ class alias_ref {
  * This is useful when you have a call which is initiated from C++-land, and therefore
  * doesn't automatically get a local JNI frame managed for you by the JNI framework.
  */
-class FBEXPORT JniLocalScope {
+class JniLocalScope {
 public:
   JniLocalScope(JNIEnv* p_env, jint capacity);
   ~JniLocalScope();

lib/fb/src/main/cpp/include/fbjni/detail/Registration-inl.h

@@ -0,0 +1,166 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#pragma once
+
+#include "Exceptions.h"
+#include "Hybrid.h"
+
+namespace facebook {
+namespace jni {
+
+namespace detail {
+
+#ifdef __i386__
+// X86 ABI forces 16 byte stack allignment on calls. Unfortunately
+// sometimes Dalvik chooses not to obey the ABI:
+// - https://code.google.com/p/android/issues/detail?id=61012
+// - https://android.googlesource.com/platform/ndk/+/81696d2%5E!/
+// Therefore, we tell the compiler to re-align the stack on entry
+// to our JNI functions.
+#define JNI_ENTRY_POINT __attribute__((force_align_arg_pointer))
+#else
+#define JNI_ENTRY_POINT
+#endif
+
+template <typename R>
+struct CreateDefault {
+  static R create() {
+    return R{};
+  }
+};
+
+template <>
+struct CreateDefault<void> {
+  static void create() {}
+};
+
+template <typename R>
+using Converter = Convert<typename std::decay<R>::type>;
+
+template <typename F, F func, typename R, typename... Args>
+struct WrapForVoidReturn {
+  static typename Converter<R>::jniType call(Args&&... args) {
+    return Converter<R>::toJniRet(func(std::forward<Args>(args)...));
+  }
+};
+
+template <typename F, F func, typename... Args>
+struct WrapForVoidReturn<F, func, void, Args...> {
+  static void call(Args&&... args) {
+    func(std::forward<Args>(args)...);
+  }
+};
+
+// registration wrapper for legacy JNI-style functions
+template<typename F, F func, typename C, typename R, typename... Args>
+struct BareJniWrapper {
+  JNI_ENTRY_POINT static R call(JNIEnv* env, jobject obj, Args... args) {
+    detail::JniEnvCacher jec(env);
+    try {
+      return (*func)(env, static_cast<JniType<C>>(obj), args...);
+    } catch (...) {
+      translatePendingCppExceptionToJavaException();
+      return CreateDefault<R>::create();
+    }
+  }
+};
+
+// registration wrappers for functions, with autoconversion of arguments.
+template<typename F, F func, typename C, typename R, typename... Args>
+struct FunctionWrapper {
+  using jniRet = typename Converter<R>::jniType;
+  JNI_ENTRY_POINT static jniRet call(JNIEnv* env, jobject obj, typename Converter<Args>::jniType... args) {
+    detail::JniEnvCacher jec(env);
+    try {
+      return WrapForVoidReturn<F, func, R, JniType<C>, Args...>::call(
+          static_cast<JniType<C>>(obj), Converter<Args>::fromJni(args)...);
+    } catch (...) {
+      translatePendingCppExceptionToJavaException();
+      return CreateDefault<jniRet>::create();
+    }
+  }
+};
+
+// registration wrappers for non-static methods, with autoconvertion of arguments.
+template<typename M, M method, typename C, typename R, typename... Args>
+struct MethodWrapper {
+  using jhybrid = typename C::jhybridobject;
+  static R dispatch(alias_ref<jhybrid> ref, Args&&... args) {
+    try {
+      // This is usually a noop, but if the hybrid object is a
+      // base class of other classes which register JNI methods,
+      // this will get the right type for the registered method.
+      auto cobj = static_cast<C*>(ref->cthis());
+      return (cobj->*method)(std::forward<Args>(args)...);
+    } catch (const std::exception& ex) {
+      C::mapException(ex);
+      throw;
+    }
+  }
+
+  JNI_ENTRY_POINT static typename Converter<R>::jniType call(
+      JNIEnv* env, jobject obj, typename Converter<Args>::jniType... args) {
+    return FunctionWrapper<R(*)(alias_ref<jhybrid>, Args&&...), dispatch, jhybrid, R, Args...>::call(env, obj, args...);
+  }
+};
+
+template<typename F, F func, typename C, typename R, typename... Args>
+inline NativeMethodWrapper* exceptionWrapJNIMethod(R (*)(JNIEnv*, C, Args... args)) {
+  // This intentionally erases the real type; JNI will do it anyway
+  return reinterpret_cast<NativeMethodWrapper*>(&(BareJniWrapper<F, func, C, R, Args...>::call));
+}
+
+template<typename F, F func, typename C, typename R, typename... Args>
+inline NativeMethodWrapper* exceptionWrapJNIMethod(R (*)(alias_ref<C>, Args... args)) {
+  // This intentionally erases the real type; JNI will do it anyway
+  return reinterpret_cast<NativeMethodWrapper*>(&(FunctionWrapper<F, func, C, R, Args...>::call));
+}
+
+template<typename M, M method, typename C, typename R, typename... Args>
+inline NativeMethodWrapper* exceptionWrapJNIMethod(R (C::*method0)(Args... args)) {
+  (void)method0;
+  // This intentionally erases the real type; JNI will do it anyway
+  return reinterpret_cast<NativeMethodWrapper*>(&(MethodWrapper<M, method, C, R, Args...>::call));
+}
+
+template<typename R, typename C, typename... Args>
+inline std::string makeDescriptor(R (*)(JNIEnv*, C, Args... args)) {
+  return jmethod_traits<R(Args...)>::descriptor();
+}
+
+template<typename R, typename C, typename... Args>
+inline std::string makeDescriptor(R (*)(alias_ref<C>, Args... args)) {
+  return jmethod_traits_from_cxx<R(Args...)>::descriptor();
+}
+
+template<typename R, typename C, typename... Args>
+inline std::string makeDescriptor(R (C::*)(Args... args)) {
+  return jmethod_traits_from_cxx<R(Args...)>::descriptor();
+}
+
+template<typename R, typename ...Args>
+template<R(*func)(Args...)>
+JNI_ENTRY_POINT R CriticalMethod<R(*)(Args...)>::call(alias_ref<jclass>, Args... args) noexcept {
+  static_assert(
+    IsJniPrimitive<R>() || std::is_void<R>(),
+    "Critical Native Methods may only return primitive JNI types, or void.");
+  static_assert(
+    AreJniPrimitives<Args...>(),
+    "Critical Native Methods may only use primitive JNI types as parameters");
+
+  return func(std::forward<Args>(args)...);
+}
+
+template<typename R, typename ...Args>
+template<R(*func)(Args...)>
+inline std::string CriticalMethod<R(*)(Args...)>::desc() {
+  return makeDescriptor(call<func>);
+}
+
+}
+
+}}

lib/fb/src/main/cpp/include/fbjni/detail/Registration.h

@@ -17,28 +17,14 @@ namespace detail {
 // This uses the real JNI function as a non-type template parameter to
 // cause a (static member) function to exist with the same signature,
 // but with try/catch exception translation.
-template<typename F, F func, typename C, typename... Args>
-NativeMethodWrapper* exceptionWrapJNIMethod(void (*func0)(JNIEnv*, jobject, Args... args));
-
-// Same as above, but for non-void return types.
 template<typename F, F func, typename C, typename R, typename... Args>
 NativeMethodWrapper* exceptionWrapJNIMethod(R (*func0)(JNIEnv*, jobject, Args... args));
 
 // Automatically wrap object argument, and don't take env explicitly.
-template<typename F, F func, typename C, typename... Args>
-NativeMethodWrapper* exceptionWrapJNIMethod(void (*func0)(alias_ref<C>, Args... args));
-
-// Automatically wrap object argument, and don't take env explicitly,
-// non-void return type.
 template<typename F, F func, typename C, typename R, typename... Args>
 NativeMethodWrapper* exceptionWrapJNIMethod(R (*func0)(alias_ref<C>, Args... args));
 
-// Extract C++ instance from object, and invoke given method on it.
-template<typename M, M method, typename C, typename... Args>
-NativeMethodWrapper* exceptionWrapJNIMethod(void (C::*method0)(Args... args));
-
 // Extract C++ instance from object, and invoke given method on it,
-// non-void return type
 template<typename M, M method, typename C, typename R, typename... Args>
 NativeMethodWrapper* exceptionWrapJNIMethod(R (C::*method0)(Args... args));
 
@@ -57,15 +43,15 @@ std::string makeDescriptor(R (*func)(alias_ref<C>, Args... args));
 template<typename R, typename C, typename... Args>
 std::string makeDescriptor(R (C::*method0)(Args... args));
 
-template <typename F>
+template<typename F>
 struct CriticalMethod;
 
-template <typename R, typename... Args>
+template<typename R, typename ...Args>
-struct CriticalMethod<R (*)(Args...)> {
+struct CriticalMethod<R(*)(Args...)> {
-  template <R (*func)(Args...)>
+  template<R(*func)(Args...)>
   static R call(alias_ref<jclass>, Args... args) noexcept;
 
-  template <R (*func)(Args...)>
+  template<R(*func)(Args...)>
   inline static std::string desc();
 };
 
@@ -91,6 +77,7 @@ struct CriticalMethod<R (*)(Args...)> {
 #define makeNativeMethodN(a, b, c, count, ...) makeNativeMethod ## count
 #define makeNativeMethod(...) makeNativeMethodN(__VA_ARGS__, 3, 2)(__VA_ARGS__)
 
+
 // FAST CALLS / CRITICAL CALLS
 // Android up to and including v7 supports "fast calls" by prefixing the method
 // signature with an exclamation mark.

lib/fb/src/main/cpp/include/fbjni/detail/TypeTraits.h

@@ -86,6 +86,7 @@ constexpr bool AreJniPrimitives() {
   return are_jni_primitives<Ts...>::value;
 }
 
+
 /// Metafunction to determine whether a type is a JNI array of primitives or not
 template <typename T>
 struct is_jni_primitive_array :

lib/fb/src/main/cpp/include/fbjni/detail/utf8.h

@@ -10,8 +10,6 @@
 
 #include <jni.h>
 
-#include <fb/visibility.h>
-
 namespace facebook {
 namespace jni {
 
@@ -42,28 +40,18 @@ std::string utf16toUTF8(const uint16_t* utf16Bytes, size_t len) noexcept;
 //  - http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/functions.html
 //  - https://docs.oracle.com/javase/6/docs/api/java/io/DataInput.html#modified-utf-8
 
-class FBEXPORT LocalString {
+// JString to UTF16 extractor using RAII idiom. Note that the
-public:
+// ctor/dtor use GetStringCritical/ReleaseStringCritical, so this
-  // Assumes UTF8 encoding and make a required convertion to modified UTF-8 when the string
+// class is subject to the restrictions imposed by those functions.
-  // contains unicode supplementary characters.
-  explicit LocalString(const std::string& str);
-  explicit LocalString(const char* str);
-  jstring string() const {
-    return m_string;
-  }
-  ~LocalString();
-private:
-  jstring m_string;
-};
-
-// JString to UTF16 extractor using RAII idiom
 class JStringUtf16Extractor {
 public:
   JStringUtf16Extractor(JNIEnv* env, jstring javaString)
   : env_(env)
   , javaString_(javaString)
+  , length_(0)
   , utf16String_(nullptr) {
     if (env_ && javaString_) {
+      length_ = env_->GetStringLength(javaString_);
       utf16String_ = env_->GetStringCritical(javaString_, nullptr);
     }
   }
@@ -74,18 +62,20 @@ public:
     }
   }
 
-  operator const jchar* () const {
+  const jsize length() const {
+    return length_;
+  }
+
+  const jchar* chars() const {
     return utf16String_;
   }
 
 private:
   JNIEnv* env_;
   jstring javaString_;
+  jsize length_;
   const jchar* utf16String_;
 };
 
-// The string from JNI is converted to standard UTF-8 if the string contains supplementary
+}
-// characters.
+}
-FBEXPORT std::string fromJString(JNIEnv* env, jstring str);
-
-} }

lib/fb/src/main/cpp/include/fbjni/fbjni.h

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#pragma once
+
+#include <jni.h>
+
+#include <fbjni/detail/Environment.h>
+#include <fbjni/detail/Log.h>
+#include <fbjni/detail/Common.h>
+#include <fbjni/detail/Exceptions.h>
+#include <fbjni/detail/ReferenceAllocators.h>
+#include <fbjni/detail/References.h>
+#include <fbjni/detail/Meta.h>
+#include <fbjni/detail/CoreClasses.h>
+#include <fbjni/detail/Iterator.h>
+#include <fbjni/detail/Hybrid.h>
+#include <fbjni/detail/Registration.h>
+#include <fbjni/detail/JWeakReference.h>

lib/fb/src/main/cpp/include/jni/Countable.h

@@ -1,33 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-#include <jni.h>
-
-#include <fb/Countable.h>
-#include <fb/RefPtr.h>
-#include <fb/visibility.h>
-
-namespace facebook {
-namespace jni {
-
-FBEXPORT const RefPtr<Countable>& countableFromJava(JNIEnv* env, jobject obj);
-
-template <typename T> RefPtr<T> extractRefPtr(JNIEnv* env, jobject obj) {
-  return static_cast<RefPtr<T>>(countableFromJava(env, obj));
-}
-
-template <typename T> RefPtr<T> extractPossiblyNullRefPtr(JNIEnv* env, jobject obj) {
-  return obj ? extractRefPtr<T>(env, obj) : nullptr;
-}
-
-FBEXPORT void setCountableForJava(JNIEnv* env, jobject obj, RefPtr<Countable>&& countable);
-
-void CountableOnLoad(JNIEnv* env);
-
-} }
-

lib/fb/src/main/cpp/include/jni/GlobalReference.h

@@ -1,88 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-#include <memory>
-#include <type_traits>
-
-#include <jni.h>
-
-#include <fb/Environment.h>
-
-namespace facebook { namespace jni {
-
-template<typename T>
-class GlobalReference {
-  static_assert(std::is_convertible<T, jobject>::value,
-                "GlobalReference<T> instantiated with type that is not "
-                "convertible to jobject");
-
- public:
-  explicit GlobalReference(T globalReference) :
-    reference_(globalReference? Environment::current()->NewGlobalRef(globalReference) : nullptr) {
-  }
-
-  ~GlobalReference() {
-    reset();
-  }
-
-  GlobalReference() :
-    reference_(nullptr) {
-  }
-
-  // enable move constructor and assignment
-  GlobalReference(GlobalReference&& rhs) :
-    reference_(std::move(rhs.reference_)) {
-    rhs.reference_ = nullptr;
-  }
-
-  GlobalReference& operator=(GlobalReference&& rhs) {
-    if (this != &rhs) {
-      reset();
-      reference_ = std::move(rhs.reference_);
-      rhs.reference_ = nullptr;
-    }
-    return *this;
-  }
-
-  GlobalReference(const GlobalReference<T>& rhs) :
-    reference_{} {
-    reset(rhs.get());
-  }
-
-  GlobalReference& operator=(const GlobalReference<T>& rhs) {
-    if (this == &rhs) {
-      return *this;
-    }
-    reset(rhs.get());
-    return *this;
-  }
-
-  explicit operator bool() const {
-    return (reference_ != nullptr);
-  }
-
-  T get() const {
-    return reinterpret_cast<T>(reference_);
-  }
-
-  void reset(T globalReference = nullptr) {
-    if (reference_) {
-      Environment::current()->DeleteGlobalRef(reference_);
-    }
-    if (globalReference) {
-      reference_ = Environment::current()->NewGlobalRef(globalReference);
-    } else {
-      reference_ = nullptr;
-    }
-  }
-
- private:
-  jobject reference_;
-};
-
-}}

lib/fb/src/main/cpp/include/jni/LocalReference.h

@@ -1,34 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-#include <memory>
-#include <type_traits>
-
-#include <jni.h>
-
-#include <fb/Environment.h>
-
-namespace facebook {
-namespace jni {
-
-template<class T>
-struct LocalReferenceDeleter {
-  static_assert(std::is_convertible<T, jobject>::value,
-    "LocalReferenceDeleter<T> instantiated with type that is not convertible to jobject");
-  void operator()(T localReference) {
-    if (localReference != nullptr) {
-      Environment::current()->DeleteLocalRef(localReference);
-    }
-  } 
- };
-
-template<class T>
-using LocalReference =
-  std::unique_ptr<typename std::remove_pointer<T>::type, LocalReferenceDeleter<T>>;
-
-} }

lib/fb/src/main/cpp/include/jni/Registration.h

@@ -1,24 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-#include <jni.h>
-#include <initializer_list>
-#include <fb/assert.h>
-
-namespace facebook {
-namespace jni {
-
-static inline void registerNatives(JNIEnv* env, jclass cls, std::initializer_list<JNINativeMethod> methods) {
-  auto result = env->RegisterNatives(cls, methods.begin(), methods.size());
-  FBASSERT(result == 0);
-}
-
-static inline void registerNatives(JNIEnv* env, const char* cls, std::initializer_list<JNINativeMethod> list) {
-  registerNatives(env, env->FindClass(cls), list);
-}
-
-} }

lib/fb/src/main/cpp/include/jni/WeakReference.h

@@ -1,52 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-#include <string>
-#include <jni.h>
-#include <fb/noncopyable.h>
-#include <fb/Countable.h>
-#include <fb/visibility.h>
-
-
-namespace facebook {
-namespace jni {
-
-class FBEXPORT WeakReference : public Countable {
-public:
-  typedef RefPtr<WeakReference> Ptr;
-  WeakReference(jobject strongRef);
-  ~WeakReference();
-  jweak weakRef() {
-    return m_weakReference;
-  }
-
-private:
-  jweak m_weakReference;
-};
-
-// This class is intended to take a weak reference and turn it into a strong
-// local reference. Consequently, it should only be allocated on the stack.
-class FBEXPORT ResolvedWeakReference : public noncopyable {
-public:
-  ResolvedWeakReference(jobject weakRef);
-  ResolvedWeakReference(const RefPtr<WeakReference>& weakRef);
-  ~ResolvedWeakReference();
-
-  operator jobject () {
-    return m_strongReference;
-  }
-
-  explicit operator bool () {
-    return m_strongReference != nullptr;
-  }
-
-private:
-  jobject m_strongReference;
-};
-
-} }
-

lib/fb/src/main/cpp/include/jni/jni_helpers.h

@@ -1,136 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#pragma once
-
-#include <jni.h>
-
-#include <fb/visibility.h>
-
-namespace facebook {
-
-/**
- * Instructs the JNI environment to throw an exception.
- *
- * @param pEnv JNI environment
- * @param szClassName class name to throw
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-FBEXPORT jint throwException(JNIEnv* pEnv, const char* szClassName, const char* szFmt, va_list va_args);
-
-/**
- * Instructs the JNI environment to throw a NoClassDefFoundError.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-FBEXPORT jint throwNoClassDefError(JNIEnv* pEnv, const char* szFmt, ...);
-
-/**
- * Instructs the JNI environment to throw a RuntimeException.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-FBEXPORT jint throwRuntimeException(JNIEnv* pEnv, const char* szFmt, ...);
-
-/**
- * Instructs the JNI environment to throw a IllegalArgumentException.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-FBEXPORT jint throwIllegalArgumentException(JNIEnv* pEnv, const char* szFmt, ...);
-
-/**
- * Instructs the JNI environment to throw a IllegalStateException.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-FBEXPORT jint throwIllegalStateException(JNIEnv* pEnv, const char* szFmt, ...);
-
-/**
- * Instructs the JNI environment to throw an IOException.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-FBEXPORT jint throwIOException(JNIEnv* pEnv, const char* szFmt, ...);
-
-/**
- * Instructs the JNI environment to throw an AssertionError.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-FBEXPORT jint throwAssertionError(JNIEnv* pEnv, const char* szFmt, ...);
-
-/**
- * Instructs the JNI environment to throw an OutOfMemoryError.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-FBEXPORT jint throwOutOfMemoryError(JNIEnv* pEnv, const char* szFmt, ...);
-
-/**
- * Finds the specified class. If it's not found, instructs the JNI environment to throw an
- * exception.
- *
- * @param pEnv JNI environment
- * @param szClassName the classname to find in JNI format (e.g. "java/lang/String")
- * @return the class or NULL if not found (in which case a pending exception will be queued). This
- *     returns a global reference (JNIEnv::NewGlobalRef).
- */
-FBEXPORT jclass findClassOrThrow(JNIEnv *pEnv, const char* szClassName);
-
-/**
- * Finds the specified field of the specified class. If it's not found, instructs the JNI
- * environment to throw an exception.
- *
- * @param pEnv JNI environment
- * @param clazz the class to lookup the field in
- * @param szFieldName the name of the field to find
- * @param szSig the signature of the field
- * @return the field or NULL if not found (in which case a pending exception will be queued)
- */
-FBEXPORT jfieldID getFieldIdOrThrow(JNIEnv* pEnv, jclass clazz, const char* szFieldName, const char* szSig);
-
-/**
- * Finds the specified method of the specified class. If it's not found, instructs the JNI
- * environment to throw an exception.
- *
- * @param pEnv JNI environment
- * @param clazz the class to lookup the method in
- * @param szMethodName the name of the method to find
- * @param szSig the signature of the method
- * @return the method or NULL if not found (in which case a pending exception will be queued)
- */
-FBEXPORT jmethodID getMethodIdOrThrow(
-    JNIEnv* pEnv,
-    jclass clazz,
-    const char* szMethodName,
-    const char* szSig);
-
-} // namespace facebook
-

lib/fb/src/main/cpp/include/lyra/lyra.h

@@ -7,12 +7,9 @@
 #pragma once
 
 #include <iomanip>
-#include <iostream>
 #include <string>
 #include <vector>
 
-#include <fb/visibility.h>
-
 namespace facebook {
 namespace lyra {
 
@@ -20,17 +17,21 @@ constexpr size_t kDefaultLimit = 64;
 
 using InstructionPointer = const void*;
 
-class FBEXPORT StackTraceElement {
+class StackTraceElement {
  public:
   StackTraceElement(InstructionPointer absoluteProgramCounter,
                     InstructionPointer libraryBase,
-                    InstructionPointer functionAddress, std::string libraryName,
+                    InstructionPointer functionAddress,
+                    std::string libraryName,
                     std::string functionName)
       : absoluteProgramCounter_{absoluteProgramCounter},
         libraryBase_{libraryBase},
         functionAddress_{functionAddress},
         libraryName_{std::move(libraryName)},
-        functionName_{std::move(functionName)} {}
+        functionName_{std::move(functionName)},
+        hasBuildId_{false},
+        buildId_{}
+  {}
 
   InstructionPointer libraryBase() const noexcept { return libraryBase_; }
 
@@ -67,14 +68,28 @@ class FBEXPORT StackTraceElement {
     return absoluteabsoluteProgramCounter - absoluteSymbol;
   }
 
+  std::string buildId() const;
  private:
   const InstructionPointer absoluteProgramCounter_;
   const InstructionPointer libraryBase_;
   const InstructionPointer functionAddress_;
   const std::string libraryName_;
   const std::string functionName_;
+
+  mutable bool hasBuildId_;
+  mutable std::string buildId_;
 };
 
+/**
+ * If a library identifier function is set, it is passed a libraryName
+ * for the frame, and returns a library build id string, which will be
+ * included in the logged stack trace.  The most common use for this
+ * will be correlating stack traces with breakpad identifiers.
+ */
+typedef std::string (*LibraryIdentifierFunctionType)(const std::string&);
+
+void setLibraryIdentifierFunction(LibraryIdentifierFunctionType func);
+
 /**
  * Populate the vector with the current stack trace
  *
@@ -91,8 +106,7 @@ class FBEXPORT StackTraceElement {
  *
  * @param skip The number of frames to skip before capturing the trace
  */
-FBEXPORT void getStackTrace(std::vector<InstructionPointer>& stackTrace,
+void getStackTrace(std::vector<InstructionPointer>& stackTrace, size_t skip = 0);
-                            size_t skip = 0);
 
 /**
  * Creates a vector and populates it with the current stack trace
@@ -108,7 +122,7 @@ FBEXPORT void getStackTrace(std::vector<InstructionPointer>& stackTrace,
  *
  * @limit The maximum number of frames captured
  */
-FBEXPORT inline std::vector<InstructionPointer> getStackTrace(
+inline std::vector<InstructionPointer> getStackTrace(
     size_t skip = 0,
     size_t limit = kDefaultLimit) {
   auto stackTrace = std::vector<InstructionPointer>{};
@@ -125,7 +139,7 @@ FBEXPORT inline std::vector<InstructionPointer> getStackTrace(
  *
  * @param stackTrace The input stack trace
  */
-FBEXPORT void getStackTraceSymbols(std::vector<StackTraceElement>& symbols,
+void getStackTraceSymbols(std::vector<StackTraceElement>& symbols,
                           const std::vector<InstructionPointer>& trace);
 
 /**
@@ -133,7 +147,7 @@ FBEXPORT void getStackTraceSymbols(std::vector<StackTraceElement>& symbols,
  *
  * @param stackTrace The input stack trace
  */
-FBEXPORT inline std::vector<StackTraceElement> getStackTraceSymbols(
+inline std::vector<StackTraceElement> getStackTraceSymbols(
     const std::vector<InstructionPointer>& trace) {
   auto symbols = std::vector<StackTraceElement>{};
   getStackTraceSymbols(symbols, trace);
@@ -152,7 +166,7 @@ FBEXPORT inline std::vector<StackTraceElement> getStackTraceSymbols(
  *
  * @param limit The maximum number of frames captured
  */
-FBEXPORT inline std::vector<StackTraceElement> getStackTraceSymbols(
+inline std::vector<StackTraceElement> getStackTraceSymbols(
     size_t skip = 0,
     size_t limit = kDefaultLimit) {
   return getStackTraceSymbols(getStackTrace(skip + 1, limit));
@@ -161,12 +175,21 @@ FBEXPORT inline std::vector<StackTraceElement> getStackTraceSymbols(
 /**
  * Formatting a stack trace element
  */
-FBEXPORT std::ostream& operator<<(std::ostream& out, const StackTraceElement& elm);
+std::ostream& operator<<(std::ostream& out, const StackTraceElement& elm);
 
 /**
  * Formatting a stack trace
  */
-FBEXPORT std::ostream& operator<<(std::ostream& out,
+std::ostream& operator<<(std::ostream& out,
                          const std::vector<StackTraceElement>& trace);
+
+/**
+ * Log stack trace
+ *
+ * Makes it possible to log a trace without using a temporary stream when the
+ * underlying log API is not stream based.
+ */
+void logStackTrace(const std::vector<StackTraceElement>& trace);
+
 }
 }

lib/fb/src/main/cpp/include/lyra/lyra_exceptions.h

@@ -0,0 +1,84 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#pragma once
+
+#include <exception>
+#include <typeinfo>
+#include <vector>
+
+#include <lyra/lyra.h>
+
+namespace facebook {
+namespace lyra {
+
+namespace detail {
+  struct ExceptionTraceHolder {
+    ExceptionTraceHolder();
+    // Need some virtual function to make this a polymorphic type.
+    virtual ~ExceptionTraceHolder();
+    ExceptionTraceHolder(const ExceptionTraceHolder&) = delete;
+    ExceptionTraceHolder(ExceptionTraceHolder&&) = default;
+
+    std::vector<InstructionPointer> stackTrace_;
+  };
+
+  template <typename E, bool hasTraceHolder>
+  struct Holder : E, ExceptionTraceHolder {
+    Holder(E&& e) : E{std::forward<E>(e)}, ExceptionTraceHolder{} {}
+  };
+  template <typename E>
+  struct Holder<E, true> : E {
+    Holder(E&& e) : E{std::forward<E>(e)} {}
+  };
+}
+
+/**
+ * Retrieves the stack trace of an exception
+ */
+const std::vector<InstructionPointer>& getExceptionTrace(std::exception_ptr ptr);
+
+/**
+ * Throw an exception and store the stack trace. This works like
+ * std::throw_with_nested in that it will actually throw a type that is
+ * publicly derived from both E and detail::ExceptionTraceHolder.
+ */
+template <class E>
+[[noreturn]] void fbthrow(E&& exception) {
+  throw detail::Holder<E, std::is_base_of<detail::ExceptionTraceHolder, E>::value>{std::forward<E>(exception)};
+}
+
+/**
+ * Ensure that a terminate handler that logs traces is installed.
+ * setLibraryIdentifierFunction should be called first if the stack
+ * trace should log build ids for libraries.
+ */
+void ensureRegisteredTerminateHandler();
+
+/**
+ * Helper to convert an exception to a string
+ */
+std::string toString(std::exception_ptr exceptionPointer);
+
+/**
+ * lyra's cxa_throw will delegate to the original cxa throw. That pointer must
+ * be set before lyra::cxa_throw is called.
+ *
+ * One example use would be to statically compile against something that overrides __cxa_throw.
+ * That would look something like:
+ *
+ * [[noreturn]] void __cxa_throw(void* obj, const std::type_info* type, void (*destructor) (void*)) {
+ *   static auto initializer = lyra::original_cxa_throw = lookupOriginalCxaThrow();
+ *   lyra::cxa_throw(obj, type, destructor);
+ * }
+ */
+[[gnu::noreturn]] extern void (*original_cxa_throw)(void*, const std::type_info*, void (*) (void*));
+[[noreturn]] void cxa_throw(void* obj, const std::type_info* type, void (*destructor) (void *));
+
+void enableCxaThrowHookBacktraces(bool enable);
+
+}
+}

lib/fb/src/main/cpp/jni/ByteBuffer.cpp

@@ -4,21 +4,51 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
-#include <fb/fbjni/ByteBuffer.h>
+#include <fbjni/ByteBuffer.h>
 
 #include <stdexcept>
 
-#include <fb/fbjni/References.h>
-
 namespace facebook {
 namespace jni {
 
-namespace {
+void JBuffer::rewind() const {
-local_ref<JByteBuffer> createEmpty() {
+  static auto meth = javaClassStatic()->getMethod<alias_ref<JBuffer>()>("rewind");
-  static auto cls = JByteBuffer::javaClassStatic();
+  meth(self());
-  static auto meth = cls->getStaticMethod<JByteBuffer::javaobject(int)>("allocateDirect");
-  return meth(cls, 0);
 }
+
+void* JBuffer::getDirectAddress() const {
+  if (!self()) {
+    throwNewJavaException("java/lang/NullPointerException", "java.lang.NullPointerException");
+  }
+  void* addr = Environment::current()->GetDirectBufferAddress(self());
+  FACEBOOK_JNI_THROW_PENDING_EXCEPTION();
+  if (!addr) {
+    throw std::runtime_error(
+        isDirect() ?
+          "Attempt to get direct bytes of non-direct buffer." :
+          "Error getting direct bytes of buffer.");
+  }
+  return addr;
+}
+
+size_t JBuffer::getDirectCapacity() const {
+  if (!self()) {
+    throwNewJavaException("java/lang/NullPointerException", "java.lang.NullPointerException");
+  }
+  int size = Environment::current()->GetDirectBufferCapacity(self());
+  FACEBOOK_JNI_THROW_PENDING_EXCEPTION();
+  if (size < 0) {
+    throw std::runtime_error(
+        isDirect() ?
+          "Attempt to get direct size of non-direct buffer." :
+          "Error getting direct size of buffer.");
+  }
+  return static_cast<size_t>(size);
+}
+
+bool JBuffer::isDirect() const {
+  static auto meth = javaClassStatic()->getMethod<jboolean()>("isDirect");
+  return meth(self());
 }
 
 local_ref<JByteBuffer> JByteBuffer::wrapBytes(uint8_t* data, size_t size) {
@@ -26,7 +56,7 @@ local_ref<JByteBuffer> JByteBuffer::wrapBytes(uint8_t* data, size_t size) {
   // dalvik returns an invalid result and Android's art aborts if size == 0.
   // Workaround this by using a slow path through Java in that case.
   if (!size) {
-    return createEmpty();
+    return allocateDirect(0);
   }
   auto res = adopt_local(static_cast<javaobject>(Environment::current()->NewDirectByteBuffer(data, size)));
   FACEBOOK_JNI_THROW_PENDING_EXCEPTION();
@@ -36,39 +66,10 @@ local_ref<JByteBuffer> JByteBuffer::wrapBytes(uint8_t* data, size_t size) {
   return res;
 }
 
-uint8_t* JByteBuffer::getDirectBytes() const {
+local_ref<JByteBuffer> JByteBuffer::allocateDirect(jint size) {
-  if (!self()) {
+  static auto cls = JByteBuffer::javaClassStatic();
-    throwNewJavaException("java/lang/NullPointerException", "java.lang.NullPointerException");
+  static auto meth = cls->getStaticMethod<JByteBuffer::javaobject(int)>("allocateDirect");
-  }
+  return meth(cls, size);
-  void* bytes = Environment::current()->GetDirectBufferAddress(self());
-  FACEBOOK_JNI_THROW_PENDING_EXCEPTION();
-  if (!bytes) {
-    throw std::runtime_error(
-        isDirect() ?
-          "Attempt to get direct bytes of non-direct byte buffer." :
-          "Error getting direct bytes of byte buffer.");
-  }
-  return static_cast<uint8_t*>(bytes);
-}
-
-size_t JByteBuffer::getDirectSize() const {
-  if (!self()) {
-    throwNewJavaException("java/lang/NullPointerException", "java.lang.NullPointerException");
-  }
-  int size = Environment::current()->GetDirectBufferCapacity(self());
-  FACEBOOK_JNI_THROW_PENDING_EXCEPTION();
-  if (size < 0) {
-    throw std::runtime_error(
-        isDirect() ?
-          "Attempt to get direct size of non-direct byte buffer." :
-          "Error getting direct size of byte buffer.");
-  }
-  return static_cast<size_t>(size);
-}
-
-bool JByteBuffer::isDirect() const {
-  static auto meth = javaClassStatic()->getMethod<jboolean()>("isDirect");
-  return meth(self());
 }
 
 }}

lib/fb/src/main/cpp/jni/Countable.cpp

@@ -1,66 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include <cstdint>
-#include <jni/Countable.h>
-#include <fb/Environment.h>
-#include <jni/Registration.h>
-
-namespace facebook {
-namespace jni {
-
-static jfieldID gCountableNativePtr;
-
-static RefPtr<Countable>* rawCountableFromJava(JNIEnv* env, jobject obj) {
-  FBASSERT(obj);
-  return reinterpret_cast<RefPtr<Countable>*>(env->GetLongField(obj, gCountableNativePtr));
-}
-
-const RefPtr<Countable>& countableFromJava(JNIEnv* env, jobject obj) {
-  FBASSERT(obj);
-  return *rawCountableFromJava(env, obj);
-}
-
-void setCountableForJava(JNIEnv* env, jobject obj, RefPtr<Countable>&& countable) {
-  int oldValue = env->GetLongField(obj, gCountableNativePtr);
-  FBASSERTMSGF(oldValue == 0, "Cannot reinitialize object; expected nullptr, got %x", oldValue);
-
-  FBASSERT(countable);
-  uintptr_t fieldValue = (uintptr_t) new RefPtr<Countable>(std::move(countable));
-  env->SetLongField(obj, gCountableNativePtr, fieldValue);
-}
-
-/**
- * NB: THREAD SAFETY (this comment also exists at Countable.java)
- *
- * This method deletes the corresponding native object on whatever thread the method is called
- * on. In the common case when this is called by Countable#finalize(), this will be called on the
- * system finalizer thread. If you manually call dispose on the Java object, the native object 
- * will be deleted synchronously on that thread.
- */
-void dispose(JNIEnv* env, jobject obj) {
-  // Grab the pointer
-  RefPtr<Countable>* countable = rawCountableFromJava(env, obj);
-  if (!countable) {
-    // That was easy.
-    return;
-  }
-
-  // Clear out the old value to avoid double-frees
-  env->SetLongField(obj, gCountableNativePtr, 0);
-
-  delete countable;
-}
-
-void CountableOnLoad(JNIEnv* env) {
-  jclass countable = env->FindClass("com/facebook/jni/Countable");
-  gCountableNativePtr = env->GetFieldID(countable, "mInstance", "J");
-  registerNatives(env, countable, {
-    { "dispose", "()V", (void*) dispose },
-  });
-}
-
-} }

lib/fb/src/main/cpp/jni/Environment.cpp

@@ -1,129 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include <pthread.h>
-#include <fb/log.h>
-#include <fb/StaticInitialized.h>
-#include <fb/ThreadLocal.h>
-#include <fb/Environment.h>
-#include <fb/fbjni/CoreClasses.h>
-#include <fb/fbjni/NativeRunnable.h>
-
-#include <functional>
-
-namespace facebook {
-namespace jni {
-
-namespace {
-StaticInitialized<ThreadLocal<JNIEnv>> g_env;
-JavaVM* g_vm = nullptr;
-
-struct JThreadScopeSupport : JavaClass<JThreadScopeSupport> {
-  static auto constexpr kJavaDescriptor = "Lcom/facebook/jni/ThreadScopeSupport;";
-
-  // These reinterpret_casts are a totally dangerous pattern. Don't use them. Use HybridData instead.
-  static void runStdFunction(std::function<void()>&& func) {
-    static auto method = javaClassStatic()->getStaticMethod<void(jlong)>("runStdFunction");
-    method(javaClassStatic(), reinterpret_cast<jlong>(&func));
-  }
-
-  static void runStdFunctionImpl(alias_ref<JClass>, jlong ptr) {
-    (*reinterpret_cast<std::function<void()>*>(ptr))();
-  }
-
-  static void OnLoad() {
-    // We need the javaClassStatic so that the class lookup is cached and that
-    // runStdFunction can be called from a ThreadScope-attached thread.
-    javaClassStatic()->registerNatives({
-        makeNativeMethod("runStdFunctionImpl", runStdFunctionImpl),
-      });
-  }
-};
-}
-
-/* static */
-JNIEnv* Environment::current() {
-  JNIEnv* env = g_env->get();
-  if ((env == nullptr) && (g_vm != nullptr)) {
-    if (g_vm->GetEnv((void**) &env, JNI_VERSION_1_6) != JNI_OK) {
-      FBLOGE("Error retrieving JNI Environment, thread is probably not attached to JVM");
-      // TODO(cjhopman): This should throw an exception.
-      env = nullptr;
-    } else {
-      g_env->reset(env);
-    }
-  }
-  return env;
-}
-
-/* static */
-void Environment::detachCurrentThread() {
-  auto env = g_env->get();
-  if (env) {
-    FBASSERT(g_vm);
-    g_vm->DetachCurrentThread();
-    g_env->reset();
-  }
-}
-
-struct EnvironmentInitializer {
-  EnvironmentInitializer(JavaVM* vm) {
-      FBASSERT(!g_vm);
-      FBASSERT(vm);
-      g_vm = vm;
-      g_env.initialize([] (void*) {});
-  }
-};
-
-/* static */
-void Environment::initialize(JavaVM* vm) {
-  static EnvironmentInitializer init(vm);
-}
-
-/* static */
-JNIEnv* Environment::ensureCurrentThreadIsAttached() {
-  auto env = g_env->get();
-  if (!env) {
-    FBASSERT(g_vm);
-    g_vm->AttachCurrentThread(&env, nullptr);
-    g_env->reset(env);
-  }
-  return env;
-}
-
-ThreadScope::ThreadScope()
-    : attachedWithThisScope_(false) {
-  JNIEnv* env = nullptr;
-  if (g_vm->GetEnv((void**) &env, JNI_VERSION_1_6) != JNI_EDETACHED) {
-    return;
-  }
-  env = facebook::jni::Environment::ensureCurrentThreadIsAttached();
-  FBASSERT(env);
-  attachedWithThisScope_ = true;
-}
-
-ThreadScope::~ThreadScope() {
-  if (attachedWithThisScope_) {
-    Environment::detachCurrentThread();
-  }
-}
-
-/* static */
-void ThreadScope::OnLoad() {
-  // These classes are required for ScopeWithClassLoader. Ensure they are looked up when loading.
-  JThreadScopeSupport::OnLoad();
-}
-
-/* static */
-void ThreadScope::WithClassLoader(std::function<void()>&& runnable) {
-  // TODO(cjhopman): If the classloader is already available in this scope, we
-  // shouldn't have to jump through java.
-  ThreadScope ts;
-  JThreadScopeSupport::runStdFunction(std::move(runnable));
-}
-
-} }
-

lib/fb/src/main/cpp/jni/Exceptions.cpp

@@ -1,282 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include <fb/fbjni/CoreClasses.h>
-
-#include <fb/assert.h>
-#include <fb/log.h>
-
-#include <alloca.h>
-#include <cstdlib>
-#include <ios>
-#include <stdexcept>
-#include <stdio.h>
-#include <string>
-#include <system_error>
-
-#include <jni.h>
-
-
-namespace facebook {
-namespace jni {
-
-namespace {
-class JRuntimeException : public JavaClass<JRuntimeException, JThrowable> {
- public:
-  static auto constexpr kJavaDescriptor = "Ljava/lang/RuntimeException;";
-
-  static local_ref<JRuntimeException> create(const char* str) {
-    return newInstance(make_jstring(str));
-  }
-
-  static local_ref<JRuntimeException> create() {
-    return newInstance();
-  }
-};
-
-class JIOException : public JavaClass<JIOException, JThrowable> {
- public:
-  static auto constexpr kJavaDescriptor = "Ljava/io/IOException;";
-
-  static local_ref<JIOException> create(const char* str) {
-    return newInstance(make_jstring(str));
-  }
-};
-
-class JOutOfMemoryError : public JavaClass<JOutOfMemoryError, JThrowable> {
- public:
-  static auto constexpr kJavaDescriptor = "Ljava/lang/OutOfMemoryError;";
-
-  static local_ref<JOutOfMemoryError> create(const char* str) {
-    return newInstance(make_jstring(str));
-  }
-};
-
-class JArrayIndexOutOfBoundsException : public JavaClass<JArrayIndexOutOfBoundsException, JThrowable> {
- public:
-  static auto constexpr kJavaDescriptor = "Ljava/lang/ArrayIndexOutOfBoundsException;";
-
-  static local_ref<JArrayIndexOutOfBoundsException> create(const char* str) {
-    return newInstance(make_jstring(str));
-  }
-};
-
-class JUnknownCppException : public JavaClass<JUnknownCppException, JThrowable> {
- public:
-  static auto constexpr kJavaDescriptor = "Lcom/facebook/jni/UnknownCppException;";
-
-  static local_ref<JUnknownCppException> create() {
-    return newInstance();
-  }
-
-  static local_ref<JUnknownCppException> create(const char* str) {
-    return newInstance(make_jstring(str));
-  }
-};
-
-class JCppSystemErrorException : public JavaClass<JCppSystemErrorException, JThrowable> {
- public:
-  static auto constexpr kJavaDescriptor = "Lcom/facebook/jni/CppSystemErrorException;";
-
-  static local_ref<JCppSystemErrorException> create(const std::system_error& e) {
-    return newInstance(make_jstring(e.what()), e.code().value());
-  }
-};
-
-// Exception throwing & translating functions //////////////////////////////////////////////////////
-
-// Functions that throw Java exceptions
-
-void setJavaExceptionAndAbortOnFailure(alias_ref<JThrowable> throwable) {
-  auto env = Environment::current();
-  if (throwable) {
-    env->Throw(throwable.get());
-  }
-  if (env->ExceptionCheck() != JNI_TRUE) {
-    std::abort();
-  }
-}
-
-}
-
-// Functions that throw C++ exceptions
-
-// TODO(T6618159) Take a stack dump here to save context if it results in a crash when propagated
-void throwPendingJniExceptionAsCppException() {
-  JNIEnv* env = Environment::current();
-  if (env->ExceptionCheck() == JNI_FALSE) {
-    return;
-  }
-
-  auto throwable = adopt_local(env->ExceptionOccurred());
-  if (!throwable) {
-    throw std::runtime_error("Unable to get pending JNI exception.");
-  }
-  env->ExceptionClear();
-
-  throw JniException(throwable);
-}
-
-void throwCppExceptionIf(bool condition) {
-  if (!condition) {
-    return;
-  }
-
-  auto env = Environment::current();
-  if (env->ExceptionCheck() == JNI_TRUE) {
-    throwPendingJniExceptionAsCppException();
-    return;
-  }
-
-  throw JniException();
-}
-
-void throwNewJavaException(jthrowable throwable) {
-  throw JniException(wrap_alias(throwable));
-}
-
-void throwNewJavaException(const char* throwableName, const char* msg) {
-  // If anything of the fbjni calls fail, an exception of a suitable
-  // form will be thrown, which is what we want.
-  auto throwableClass = findClassLocal(throwableName);
-  auto throwable = throwableClass->newObject(
-    throwableClass->getConstructor<jthrowable(jstring)>(),
-    make_jstring(msg).release());
-  throwNewJavaException(throwable.get());
-}
-
-// Translate C++ to Java Exception
-
-namespace {
-
-// The implementation std::rethrow_if_nested uses a dynamic_cast to determine
-// if the exception is a nested_exception. If the exception is from a library
-// built with -fno-rtti, then that will crash. This avoids that.
-void rethrow_if_nested() {
-  try {
-    throw;
-  } catch (const std::nested_exception& e) {
-    e.rethrow_nested();
-  } catch (...) {
-  }
-}
-
-// For each exception in the chain of the currently handled exception, func
-// will be called with that exception as the currently handled exception (in
-// reverse order, i.e. innermost first).
-void denest(std::function<void()> func) {
-  try {
-    throw;
-  } catch (const std::exception& e) {
-    try {
-      rethrow_if_nested();
-    } catch (...) {
-      denest(func);
-    }
-    func();
-  } catch (...) {
-    func();
-  }
-}
-}
-
-void translatePendingCppExceptionToJavaException() noexcept {
-  local_ref<JThrowable> previous;
-  auto func = [&previous] () {
-    local_ref<JThrowable> current;
-    try {
-      throw;
-    } catch(const JniException& ex) {
-      current = ex.getThrowable();
-    } catch(const std::ios_base::failure& ex) {
-      current = JIOException::create(ex.what());
-    } catch(const std::bad_alloc& ex) {
-      current = JOutOfMemoryError::create(ex.what());
-    } catch(const std::out_of_range& ex) {
-      current = JArrayIndexOutOfBoundsException::create(ex.what());
-    } catch(const std::system_error& ex) {
-      current = JCppSystemErrorException::create(ex);
-    } catch(const std::runtime_error& ex) {
-      current = JRuntimeException::create(ex.what());
-    } catch(const std::exception& ex) {
-      current = JCppException::create(ex.what());
-    } catch(const char* msg) {
-      current = JUnknownCppException::create(msg);
-    } catch(...) {
-      current = JUnknownCppException::create();
-    }
-    if (previous) {
-      current->initCause(previous);
-    }
-    previous = current;
-  };
-
-  try {
-    denest(func);
-    setJavaExceptionAndAbortOnFailure(previous);
-  } catch (std::exception& e) {
-    FBLOGE("unexpected exception in translatePendingCppExceptionToJavaException: %s", e.what());
-    // std::terminate will print the message of the pending exception e
-    std::terminate();
-  } catch (...) {
-    FBLOGE("unexpected exception in translatePendingCppExceptionToJavaException");
-    std::terminate();
-  }
-}
-
-// JniException ////////////////////////////////////////////////////////////////////////////////////
-
-const std::string JniException::kExceptionMessageFailure_ = "Unable to get exception message.";
-
-JniException::JniException() : JniException(JRuntimeException::create()) { }
-
-JniException::JniException(alias_ref<jthrowable> throwable) : isMessageExtracted_(false) {
-  throwable_ = make_global(throwable);
-}
-
-JniException::JniException(JniException &&rhs)
-    : throwable_(std::move(rhs.throwable_)),
-      what_(std::move(rhs.what_)),
-      isMessageExtracted_(rhs.isMessageExtracted_) {
-}
-
-JniException::JniException(const JniException &rhs)
-    : what_(rhs.what_), isMessageExtracted_(rhs.isMessageExtracted_) {
-  throwable_ = make_global(rhs.throwable_);
-}
-
-JniException::~JniException() {
-  ThreadScope ts;
-  throwable_.reset();
-}
-
-local_ref<JThrowable> JniException::getThrowable() const noexcept {
-  return make_local(throwable_);
-}
-
-// TODO 6900503: consider making this thread-safe.
-void JniException::populateWhat() const noexcept {
-  ThreadScope ts;
-  try {
-    what_ = throwable_->toString();
-    isMessageExtracted_ = true;
-  } catch(...) {
-    what_ = kExceptionMessageFailure_;
-  }
-}
-
-const char* JniException::what() const noexcept {
-  if (!isMessageExtracted_) {
-    populateWhat();
-  }
-  return what_.c_str();
-}
-
-void JniException::setJavaException() const noexcept {
-  setJavaExceptionAndAbortOnFailure(throwable_);
-}
-
-}}

lib/fb/src/main/cpp/jni/Hybrid.cpp

@@ -1,62 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include "fb/fbjni.h"
-
-
-namespace facebook {
-namespace jni {
-
-namespace detail {
-
-void HybridData::setNativePointer(std::unique_ptr<BaseHybridClass> new_value) {
-  static auto pointerField = getClass()->getField<jlong>("mNativePointer");
-  auto* old_value = reinterpret_cast<BaseHybridClass*>(getFieldValue(pointerField));
-  if (new_value) {
-    // Modify should only ever be called once with a non-null
-    // new_value.  If this happens again it's a programmer error, so
-    // blow up.
-    FBASSERTMSGF(old_value == 0, "Attempt to set C++ native pointer twice");
-  } else if (old_value == 0) {
-    return;
-  }
-  // delete on a null pointer is defined to be a noop.
-  delete old_value;
-  // This releases ownership from the unique_ptr, and passes the pointer, and
-  // ownership of it, to HybridData which is managed by the java GC.  The
-  // finalizer on hybridData calls resetNative which will delete the object, if
-  // resetNative has not already been called.
-  setFieldValue(pointerField, reinterpret_cast<jlong>(new_value.release()));
-}
-
-BaseHybridClass* HybridData::getNativePointer() {
-  static auto pointerField = getClass()->getField<jlong>("mNativePointer");
-  auto* value = reinterpret_cast<BaseHybridClass*>(getFieldValue(pointerField));
-  if (!value) {
-    throwNewJavaException("java/lang/NullPointerException", "java.lang.NullPointerException");
-  }
-  return value;
-}
-
-local_ref<HybridData> HybridData::create() {
-  return newInstance();
-}
-
-}
-
-namespace {
-void resetNative(alias_ref<detail::HybridData> jthis) {
-  jthis->setNativePointer(nullptr);
-}
-}
-
-void HybridDataOnLoad() {
-  registerNatives("com/facebook/jni/HybridData", {
-      makeNativeMethod("resetNative", resetNative),
-  });
-}
-
-}}

lib/fb/src/main/cpp/jni/OnLoad.cpp

@@ -4,16 +4,15 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
-#include <jni/Countable.h>
+#include <fbjni/fbjni.h>
-#include <fb/Environment.h>
+#include <fbjni/NativeRunnable.h>
-#include <fb/fbjni.h>
-#include <fb/fbjni/NativeRunnable.h>
 
 using namespace facebook::jni;
 
-void initialize_fbjni() {
+JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
-  CountableOnLoad(Environment::current());
+  return facebook::jni::initialize(vm, [] {
     HybridDataOnLoad();
     JNativeRunnable::OnLoad();
     ThreadScope::OnLoad();
+  });
 }

lib/fb/src/main/cpp/jni/ReadableByteChannel.cpp

@@ -0,0 +1,21 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <fbjni/ReadableByteChannel.h>
+
+namespace facebook {
+namespace jni {
+
+int JReadableByteChannel::read(alias_ref<JByteBuffer> dest) const {
+  if (!self()) {
+    throwNewJavaException("java/lang/NullPointerException", "java.lang.NullPointerException");
+  }
+  static auto method = javaClassStatic()->getMethod<jint(alias_ref<JByteBuffer>)>("read");
+  return method(self(), dest);
+}
+
+}}
+

lib/fb/src/main/cpp/jni/References.cpp

@@ -1,38 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include <fb/fbjni/References.h>
-
-namespace facebook {
-namespace jni {
-
-JniLocalScope::JniLocalScope(JNIEnv* env, jint capacity)
-    : env_(env) {
-  hasFrame_ = false;
-  auto pushResult = env->PushLocalFrame(capacity);
-  FACEBOOK_JNI_THROW_EXCEPTION_IF(pushResult < 0);
-  hasFrame_ = true;
-}
-
-JniLocalScope::~JniLocalScope() {
-  if (hasFrame_) {
-    env_->PopLocalFrame(nullptr);
-  }
-}
-
-namespace internal {
-
-// Default implementation always returns true.
-// Platform-specific sources can override this.
-bool doesGetObjectRefTypeWork() __attribute__ ((weak));
-bool doesGetObjectRefTypeWork() {
-  return true;
-}
-
-}
-
-}
-}

lib/fb/src/main/cpp/jni/WeakReference.cpp

@@ -1,40 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include <fb/Environment.h>
-#include <jni/WeakReference.h>
-
-namespace facebook {
-namespace jni {
-
-WeakReference::WeakReference(jobject strongRef) :
-  m_weakReference(Environment::current()->NewWeakGlobalRef(strongRef))
-{
-}
-
-WeakReference::~WeakReference() {
-  auto env = Environment::current();
-  FBASSERTMSGF(env, "Attempt to delete jni::WeakReference from non-JNI thread");
-  env->DeleteWeakGlobalRef(m_weakReference);
-}
-
-ResolvedWeakReference::ResolvedWeakReference(jobject weakRef) :
-  m_strongReference(Environment::current()->NewLocalRef(weakRef))
-{
-}
-
-ResolvedWeakReference::ResolvedWeakReference(const RefPtr<WeakReference>& weakRef) :
-  m_strongReference(Environment::current()->NewLocalRef(weakRef->weakRef()))
-{
-}
-
-ResolvedWeakReference::~ResolvedWeakReference() {
-  if (m_strongReference)
-    Environment::current()->DeleteLocalRef(m_strongReference);
-}
-
-} }
-

lib/fb/src/main/cpp/jni/detail/Environment.cpp

@@ -0,0 +1,291 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <fbjni/fbjni.h>
+
+#include <functional>
+#include <pthread.h>
+
+namespace facebook {
+namespace jni {
+
+namespace {
+
+JavaVM* g_vm = nullptr;
+
+struct EnvironmentInitializer {
+  EnvironmentInitializer(JavaVM* vm) {
+      FBJNI_ASSERT(!g_vm);
+      FBJNI_ASSERT(vm);
+      g_vm = vm;
+  }
+};
+
+int getEnv(JNIEnv** env) {
+  FBJNI_ASSERT(g_vm);
+  // g_vm->GetEnv() might not clear the env* in failure cases.
+  *env = nullptr;
+  jint ret = g_vm->GetEnv((void**)env, JNI_VERSION_1_6);
+  // Other possibilites are that JNI_VERSION_1_6 is invalid, or some
+  // unknown return was received.
+  FBJNI_ASSERT(ret == JNI_OK || ret == JNI_EDETACHED);
+  return ret;
+}
+
+// Some jni.h define the first arg to AttachCurrentThread as void**,
+// and some as JNIEnv**.  This hack allows both to work.
+
+template <typename>
+struct AttachTraits;
+
+template <>
+struct AttachTraits<jint(JavaVM::*)(JNIEnv**, void*)> {
+  using EnvType = JNIEnv*;
+};
+
+template <>
+struct AttachTraits<jint(JavaVM::*)(void**, void*)> {
+  using EnvType = void*;
+};
+
+JNIEnv* attachCurrentThread() {
+  JavaVMAttachArgs args{JNI_VERSION_1_6, nullptr, nullptr};
+  using AttachEnvType =
+      typename AttachTraits<decltype(&JavaVM::AttachCurrentThread)>::EnvType;
+  AttachEnvType env;
+  auto result = g_vm->AttachCurrentThread(&env, &args);
+  FBJNI_ASSERT(result == JNI_OK);
+  return reinterpret_cast<JNIEnv*>(env);
+}
+
+}
+
+/* static */
+void Environment::initialize(JavaVM* vm) {
+  static EnvironmentInitializer init(vm);
+}
+
+namespace {
+
+pthread_key_t makeKey() {
+  pthread_key_t key;
+  int ret = pthread_key_create(&key, nullptr);
+  if (ret != 0) {
+    FBJNI_LOGF("pthread_key_create failed: %d", ret);
+  }
+  return key;
+}
+
+pthread_key_t getTLKey() {
+  static pthread_key_t key = makeKey();
+  return key;
+}
+
+inline detail::TLData* getTLData(pthread_key_t key) {
+  return reinterpret_cast<detail::TLData*>(pthread_getspecific(key));
+}
+
+inline void setTLData(pthread_key_t key, detail::TLData* data) {
+  int ret = pthread_setspecific(key, data);
+  if (ret != 0) {
+    (void) ret;
+    FBJNI_LOGF("pthread_setspecific failed: %d", ret);
+  }
+}
+
+// This returns non-nullptr iff the env was cached from java.  So it
+// can return nullptr for a thread which has been registered.
+inline JNIEnv* cachedOrNull() {
+  detail::TLData* pdata = getTLData(getTLKey());
+  return (pdata ? pdata->env : nullptr);
+}
+
+}
+
+namespace detail {
+
+// This will return a cached env if there is one, or get one from JNI
+// if the thread has already been attached some other way.  If it
+// returns nullptr, then the thread has never been registered, or the
+// VM has never been set up for fbjni.
+
+JNIEnv* currentOrNull() {
+  if (!g_vm) {
+    return nullptr;
+  }
+
+  detail::TLData* pdata = getTLData(getTLKey());
+  if (pdata && pdata->env) {
+    return pdata->env;
+  }
+
+  JNIEnv* env;
+  if (getEnv(&env) != JNI_OK) {
+    // If there's a ThreadScope on the stack, we should have gotten a
+    // JNIEnv and not ended up here.
+    FBJNI_ASSERT(!pdata || !pdata->attached);
+  }
+  return env;
+}
+
+// To understand JniEnvCacher and ThreadScope, it is helpful to
+// realize that if a flagged JniEnvCacher is on the stack, then a
+// flagged ThreadScope cannot be after it.  If a flagged ThreadCacher
+// is on the stack, then a JniEnvCacher *can* be after it.  So,
+// ThreadScope's setup and teardown can both assume they are the
+// first/last interesting objects, but this is not true of
+// JniEnvCacher.
+
+JniEnvCacher::JniEnvCacher(JNIEnv* env)
+  : thisCached_(false)
+{
+  FBJNI_ASSERT(env);
+
+  pthread_key_t key = getTLKey();
+  detail::TLData* pdata = getTLData(key);
+  if (pdata && pdata->env) {
+    return;
+  }
+
+  if (!pdata) {
+    pdata = &data_;
+    setTLData(key, pdata);
+    pdata->attached = false;
+  } else {
+    FBJNI_ASSERT(!pdata->env);
+  }
+
+  pdata->env = env;
+
+  thisCached_ = true;
+}
+
+JniEnvCacher::~JniEnvCacher() {
+  if (!thisCached_) {
+    return;
+  }
+
+  pthread_key_t key = getTLKey();
+  TLData* pdata = getTLData(key);
+  FBJNI_ASSERT(pdata);
+  FBJNI_ASSERT(pdata->env != nullptr);
+  pdata->env = nullptr;
+  if (!pdata->attached) {
+    setTLData(key, nullptr);
+  }
+}
+
+}
+
+ThreadScope::ThreadScope()
+  : thisAttached_(false)
+{
+  if (g_vm == nullptr) {
+    throw std::runtime_error("fbjni is uninitialized; no thread can be attached.");
+  }
+
+  JNIEnv* env;
+
+  // Check if the thread is attached somehow.
+  auto result = getEnv(&env);
+  if (result == JNI_OK) {
+    return;
+  }
+
+  // At this point, it appears there's no thread attached and no env is
+  // cached, or we would have returned already.  So there better not
+  // be TLData.
+
+  pthread_key_t key = getTLKey();
+  detail::TLData* pdata = getTLData(key);
+  FBJNI_ASSERT(pdata == nullptr);
+  setTLData(key, &data_);
+
+  attachCurrentThread();
+
+  data_.env = nullptr;
+  data_.attached = true;
+
+  thisAttached_ = true;
+}
+
+ThreadScope::~ThreadScope() {
+  if (!thisAttached_) {
+    return;
+  }
+
+  pthread_key_t key = getTLKey();
+  detail::TLData* pdata = getTLData(key);
+  FBJNI_ASSERT(pdata);
+  FBJNI_ASSERT(pdata->env == nullptr);
+  FBJNI_ASSERT(pdata->attached);
+  FBJNI_ASSERT(g_vm);
+  g_vm->DetachCurrentThread();
+  setTLData(key, nullptr);
+}
+
+/* static */
+JNIEnv* Environment::current() {
+  FBJNI_ASSERT(g_vm);
+  JNIEnv* env = detail::currentOrNull();
+  if (env == nullptr) {
+    throw std::runtime_error("Unable to retrieve jni environment. Is the thread attached?");
+  }
+  return env;
+}
+
+/* static */
+JNIEnv* Environment::ensureCurrentThreadIsAttached() {
+  FBJNI_ASSERT(g_vm);
+  JNIEnv* env = detail::currentOrNull();
+  if (env == nullptr) {
+    env = attachCurrentThread();
+    FBJNI_ASSERT(env);
+  }
+  return env;
+}
+
+namespace {
+struct JThreadScopeSupport : JavaClass<JThreadScopeSupport> {
+  static auto constexpr kJavaDescriptor = "Lcom/facebook/jni/ThreadScopeSupport;";
+
+  // These reinterpret_casts are a totally dangerous pattern. Don't use them. Use HybridData instead.
+  static void runStdFunction(std::function<void()>&& func) {
+    static const auto method = javaClassStatic()->getStaticMethod<void(jlong)>("runStdFunction");
+    method(javaClassStatic(), reinterpret_cast<jlong>(&func));
+  }
+
+  static void runStdFunctionImpl(alias_ref<JClass>, jlong ptr) {
+    (*reinterpret_cast<std::function<void()>*>(ptr))();
+  }
+
+  static void OnLoad() {
+    // We need the javaClassStatic so that the class lookup is cached and that
+    // runStdFunction can be called from a ThreadScope-attached thread.
+    javaClassStatic()->registerNatives({
+        makeNativeMethod("runStdFunctionImpl", runStdFunctionImpl),
+      });
+  }
+};
+}
+
+/* static */
+void ThreadScope::OnLoad() {
+  // These classes are required for ScopeWithClassLoader. Ensure they are looked up when loading.
+  JThreadScopeSupport::OnLoad();
+}
+
+/* static */
+void ThreadScope::WithClassLoader(std::function<void()>&& runnable) {
+  if (cachedOrNull() == nullptr) {
+    ThreadScope ts;
+    JThreadScopeSupport::runStdFunction(std::move(runnable));
+  } else {
+    runnable();
+  }
+}
+
+} }

lib/fb/src/main/cpp/jni/detail/Exceptions.cpp

@@ -0,0 +1,390 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <fbjni/detail/CoreClasses.h>
+#include <fbjni/detail/Log.h>
+
+#ifndef FBJNI_NO_EXCEPTION_PTR
+#include <lyra/lyra.h>
+#include <lyra/lyra_exceptions.h>
+#endif
+
+#include <alloca.h>
+#include <cstdlib>
+#include <ios>
+#include <stdexcept>
+#include <stdio.h>
+#include <string>
+#include <system_error>
+
+#include <jni.h>
+
+namespace facebook {
+namespace jni {
+
+namespace {
+class JRuntimeException : public JavaClass<JRuntimeException, JThrowable> {
+ public:
+  static auto constexpr kJavaDescriptor = "Ljava/lang/RuntimeException;";
+
+  static local_ref<JRuntimeException> create(const char* str) {
+    return newInstance(make_jstring(str));
+  }
+
+  static local_ref<JRuntimeException> create() {
+    return newInstance();
+  }
+};
+
+class JIOException : public JavaClass<JIOException, JThrowable> {
+ public:
+  static auto constexpr kJavaDescriptor = "Ljava/io/IOException;";
+
+  static local_ref<JIOException> create(const char* str) {
+    return newInstance(make_jstring(str));
+  }
+};
+
+class JOutOfMemoryError : public JavaClass<JOutOfMemoryError, JThrowable> {
+ public:
+  static auto constexpr kJavaDescriptor = "Ljava/lang/OutOfMemoryError;";
+
+  static local_ref<JOutOfMemoryError> create(const char* str) {
+    return newInstance(make_jstring(str));
+  }
+};
+
+class JArrayIndexOutOfBoundsException : public JavaClass<JArrayIndexOutOfBoundsException, JThrowable> {
+ public:
+  static auto constexpr kJavaDescriptor = "Ljava/lang/ArrayIndexOutOfBoundsException;";
+
+  static local_ref<JArrayIndexOutOfBoundsException> create(const char* str) {
+    return newInstance(make_jstring(str));
+  }
+};
+
+class JUnknownCppException : public JavaClass<JUnknownCppException, JThrowable> {
+ public:
+  static auto constexpr kJavaDescriptor = "Lcom/facebook/jni/UnknownCppException;";
+
+  static local_ref<JUnknownCppException> create() {
+    return newInstance();
+  }
+
+  static local_ref<JUnknownCppException> create(const char* str) {
+    return newInstance(make_jstring(str));
+  }
+};
+
+class JCppSystemErrorException : public JavaClass<JCppSystemErrorException, JThrowable> {
+ public:
+  static auto constexpr kJavaDescriptor = "Lcom/facebook/jni/CppSystemErrorException;";
+
+  static local_ref<JCppSystemErrorException> create(const std::system_error& e) {
+    return newInstance(make_jstring(e.what()), e.code().value());
+  }
+};
+
+// Exception throwing & translating functions //////////////////////////////////////////////////////
+
+// Functions that throw Java exceptions
+
+void setJavaExceptionAndAbortOnFailure(alias_ref<JThrowable> throwable) {
+  auto env = Environment::current();
+  if (throwable) {
+    env->Throw(throwable.get());
+  }
+  if (env->ExceptionCheck() != JNI_TRUE) {
+    FBJNI_LOGF("Failed to set Java exception");
+  }
+}
+
+}
+
+// Functions that throw C++ exceptions
+
+// TODO(T6618159) Inject the c++ stack into the exception's stack trace. One
+// issue: when a java exception is created, it captures the full java stack
+// across jni boundaries. lyra will only capture the c++ stack to the jni
+// boundary. So, as we pass the java exception up to c++, we need to capture
+// the c++ stack and then insert it into the correct place in the java stack
+// trace. Then, as the exception propagates across the boundaries, we will
+// slowly fill in the c++ parts of the trace.
+void throwPendingJniExceptionAsCppException() {
+  JNIEnv* env = Environment::current();
+  if (env->ExceptionCheck() == JNI_FALSE) {
+    return;
+  }
+
+  auto throwable = env->ExceptionOccurred();
+  if (!throwable) {
+    throw std::runtime_error("Unable to get pending JNI exception.");
+  }
+  env->ExceptionClear();
+
+  throw JniException(adopt_local(throwable));
+}
+
+void throwCppExceptionIf(bool condition) {
+  if (!condition) {
+    return;
+  }
+
+  auto env = Environment::current();
+  if (env->ExceptionCheck() == JNI_TRUE) {
+    throwPendingJniExceptionAsCppException();
+    return;
+  }
+
+  throw JniException();
+}
+
+void throwNewJavaException(jthrowable throwable) {
+  throw JniException(wrap_alias(throwable));
+}
+
+void throwNewJavaException(const char* throwableName, const char* msg) {
+  // If anything of the fbjni calls fail, an exception of a suitable
+  // form will be thrown, which is what we want.
+  auto throwableClass = findClassLocal(throwableName);
+  auto throwable = throwableClass->newObject(
+    throwableClass->getConstructor<jthrowable(jstring)>(),
+    make_jstring(msg).release());
+  throwNewJavaException(throwable.get());
+}
+
+// jthrowable //////////////////////////////////////////////////////////////////////////////////////
+
+local_ref<JThrowable> JThrowable::initCause(alias_ref<JThrowable> cause) {
+  static auto meth = javaClassStatic()->getMethod<javaobject(alias_ref<javaobject>)>("initCause");
+  return meth(self(), cause);
+}
+
+auto JThrowable::getStackTrace() -> local_ref<JStackTrace> {
+  static auto meth = javaClassStatic()->getMethod<JStackTrace::javaobject()>("getStackTrace");
+  return meth(self());
+}
+
+void JThrowable::setStackTrace(alias_ref<JStackTrace> stack) {
+  static auto meth = javaClassStatic()->getMethod<void(alias_ref<JStackTrace>)>("setStackTrace");
+  return meth(self(), stack);
+}
+
+auto JStackTraceElement::create(
+    const std::string& declaringClass, const std::string& methodName, const std::string& file, int line)
+    -> local_ref<javaobject> {
+  return newInstance(declaringClass, methodName, file, line);
+}
+
+std::string JStackTraceElement::getClassName() const {
+  static auto meth = javaClassStatic()->getMethod<local_ref<JString>()>("getClassName");
+  return meth(self())->toStdString();
+}
+
+std::string JStackTraceElement::getMethodName() const {
+  static auto meth = javaClassStatic()->getMethod<local_ref<JString>()>("getMethodName");
+  return meth(self())->toStdString();
+}
+
+std::string JStackTraceElement::getFileName() const {
+  static auto meth = javaClassStatic()->getMethod<local_ref<JString>()>("getFileName");
+  return meth(self())->toStdString();
+}
+
+int JStackTraceElement::getLineNumber() const {
+  static auto meth = javaClassStatic()->getMethod<jint()>("getLineNumber");
+  return meth(self());
+}
+
+// Translate C++ to Java Exception
+
+namespace {
+
+// For each exception in the chain of the exception_ptr argument, func
+// will be called with that exception (in reverse order, i.e. innermost first).
+#ifndef FBJNI_NO_EXCEPTION_PTR
+void denest(const std::function<void(std::exception_ptr)>& func, std::exception_ptr ptr) {
+  FBJNI_ASSERT(ptr);
+  try {
+    std::rethrow_exception(ptr);
+  } catch (const std::nested_exception& e) {
+    denest(func, e.nested_ptr());
+  } catch (...) {
+    // ignored.
+  }
+  func(ptr);
+  }
+#endif
+
+} // namespace
+
+#ifndef FBJNI_NO_EXCEPTION_PTR
+local_ref<JStackTraceElement> createJStackTraceElement(const lyra::StackTraceElement& cpp) {
+  return JStackTraceElement::create(
+      "|lyra|{" + cpp.libraryName() + "}", cpp.functionName(), cpp.buildId(), cpp.libraryOffset());
+}
+
+void addCppStacktraceToJavaException(alias_ref<JThrowable> java, std::exception_ptr cpp) {
+  auto cppStack = lyra::getStackTraceSymbols(
+                    (cpp == nullptr) ?
+                      lyra::getStackTrace()
+                      : lyra::getExceptionTrace(cpp));
+
+  auto javaStack = java->getStackTrace();
+  auto newStack = JThrowable::JStackTrace::newArray(javaStack->size() + cppStack.size());
+  size_t i = 0;
+  for (size_t j = 0; j < cppStack.size(); j++, i++) {
+    (*newStack)[i] = createJStackTraceElement(cppStack[j]);
+  }
+  for (size_t j = 0; j < javaStack->size(); j++, i++) {
+    (*newStack)[i] = (*javaStack)[j];
+  }
+  java->setStackTrace(newStack);
+}
+
+local_ref<JThrowable> convertCppExceptionToJavaException(std::exception_ptr ptr) {
+  FBJNI_ASSERT(ptr);
+  local_ref<JThrowable> current;
+  bool addCppStack = true;
+  try {
+    std::rethrow_exception(ptr);
+    addCppStack = false;
+  } catch (const JniException& ex) {
+    current = ex.getThrowable();
+  } catch (const std::ios_base::failure& ex) {
+    current = JIOException::create(ex.what());
+  } catch (const std::bad_alloc& ex) {
+    current = JOutOfMemoryError::create(ex.what());
+  } catch (const std::out_of_range& ex) {
+    current = JArrayIndexOutOfBoundsException::create(ex.what());
+  } catch (const std::system_error& ex) {
+    current = JCppSystemErrorException::create(ex);
+  } catch (const std::runtime_error& ex) {
+    current = JRuntimeException::create(ex.what());
+  } catch (const std::exception& ex) {
+    current = JCppException::create(ex.what());
+  } catch (const char* msg) {
+    current = JUnknownCppException::create(msg);
+  } catch (...) {
+    current = JUnknownCppException::create();
+  }
+
+  if (addCppStack) {
+    addCppStacktraceToJavaException(current, ptr);
+  }
+  return current;
+  }
+#endif
+
+local_ref<JThrowable> getJavaExceptionForCppBackTrace() {
+  return getJavaExceptionForCppBackTrace(nullptr);
+}
+
+local_ref<JThrowable> getJavaExceptionForCppBackTrace(const char* msg) {
+  local_ref<JThrowable> current =
+      msg ? JUnknownCppException::create(msg) : JUnknownCppException::create();
+#ifndef FBJNI_NO_EXCEPTION_PTR
+  addCppStacktraceToJavaException(current, nullptr);
+#endif
+  return current;
+}
+
+
+#ifndef FBJNI_NO_EXCEPTION_PTR
+local_ref<JThrowable> getJavaExceptionForCppException(std::exception_ptr ptr) {
+  FBJNI_ASSERT(ptr);
+  local_ref<JThrowable> previous;
+  auto func = [&previous] (std::exception_ptr ptr) {
+    auto current = convertCppExceptionToJavaException(ptr);
+    if (previous) {
+      current->initCause(previous);
+    }
+    previous = current;
+  };
+  denest(func, ptr);
+  return previous;
+}
+#endif
+
+void translatePendingCppExceptionToJavaException() {
+  try {
+#ifndef FBJNI_NO_EXCEPTION_PTR
+    auto exc = getJavaExceptionForCppException(std::current_exception());
+#else
+    auto exc = JUnknownCppException::create();
+#endif
+    setJavaExceptionAndAbortOnFailure(exc);
+  } catch (...) {
+#ifndef FBJNI_NO_EXCEPTION_PTR
+    FBJNI_LOGE(
+        "Unexpected error in translatePendingCppExceptionToJavaException(): %s",
+        lyra::toString(std::current_exception()).c_str());
+#else
+    FBJNI_LOGE(
+      "Unexpected error in translatePendingCppExceptionToJavaException()");
+#endif
+    std::terminate();
+  }
+}
+
+// JniException ////////////////////////////////////////////////////////////////////////////////////
+
+const std::string JniException::kExceptionMessageFailure_ = "Unable to get exception message.";
+
+JniException::JniException() : JniException(JRuntimeException::create()) { }
+
+JniException::JniException(alias_ref<jthrowable> throwable) : isMessageExtracted_(false) {
+  throwable_ = make_global(throwable);
+}
+
+JniException::JniException(JniException &&rhs)
+    : throwable_(std::move(rhs.throwable_)),
+      what_(std::move(rhs.what_)),
+      isMessageExtracted_(rhs.isMessageExtracted_) {
+}
+
+JniException::JniException(const JniException &rhs)
+    : what_(rhs.what_), isMessageExtracted_(rhs.isMessageExtracted_) {
+  throwable_ = make_global(rhs.throwable_);
+}
+
+JniException::~JniException() {
+  try {
+    ThreadScope ts;
+    throwable_.reset();
+  } catch (...) {
+    FBJNI_LOGE("Exception in ~JniException()");
+    std::terminate();
+  }
+}
+
+local_ref<JThrowable> JniException::getThrowable() const noexcept {
+  return make_local(throwable_);
+}
+
+// TODO 6900503: consider making this thread-safe.
+void JniException::populateWhat() const noexcept {
+  try {
+    ThreadScope ts;
+    what_ = throwable_->toString();
+    isMessageExtracted_ = true;
+  } catch(...) {
+    what_ = kExceptionMessageFailure_;
+  }
+}
+
+const char* JniException::what() const noexcept {
+  if (!isMessageExtracted_) {
+    populateWhat();
+  }
+  return what_.c_str();
+}
+
+void JniException::setJavaException() const noexcept {
+  setJavaExceptionAndAbortOnFailure(throwable_);
+}
+
+}}

lib/fb/src/main/cpp/jni/detail/Hybrid.cpp

@@ -0,0 +1,32 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <fbjni/fbjni.h>
+
+namespace facebook {
+namespace jni {
+
+namespace detail {
+
+local_ref<HybridData> HybridData::create() {
+  return newInstance();
+}
+
+}
+
+namespace {
+void deleteNative(alias_ref<jclass>, jlong ptr) {
+  delete reinterpret_cast<detail::BaseHybridClass*>(ptr);
+}
+}
+
+void HybridDataOnLoad() {
+  registerNatives("com/facebook/jni/HybridData$Destructor", {
+      makeNativeMethod("deleteNative", deleteNative),
+  });
+}
+
+}}

lib/fb/src/main/cpp/jni/detail/References.cpp

@@ -0,0 +1,79 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <fbjni/detail/References.h>
+
+namespace facebook {
+namespace jni {
+
+JniLocalScope::JniLocalScope(JNIEnv* env, jint capacity) : env_(env) {
+  hasFrame_ = false;
+  auto pushResult = env->PushLocalFrame(capacity);
+  FACEBOOK_JNI_THROW_EXCEPTION_IF(pushResult < 0);
+  hasFrame_ = true;
+}
+
+JniLocalScope::~JniLocalScope() {
+  if (hasFrame_) {
+    env_->PopLocalFrame(nullptr);
+  }
+}
+
+namespace {
+
+#ifdef __ANDROID__
+
+int32_t getAndroidApiLevel() {
+  // This is called from the static local initializer in
+  // isObjectRefType(), and creating fbjni references can call
+  // isObjectRefType().  So, to avoid recursively entering the block
+  // where the static is initialized (which is undefined behavior), we
+  // avoid using standard fbjni references here.
+
+  JNIEnv* env = Environment::current();
+  jclass cls = detail::findClass(env, "android/os/Build$VERSION");
+  jfieldID field = env->GetStaticFieldID(
+      cls, "SDK_INT", jtype_traits<jint>::descriptor().c_str());
+  if (!field) {
+    env->DeleteLocalRef(cls);
+  }
+  FACEBOOK_JNI_THROW_EXCEPTION_IF(!field);
+  int32_t ret = env->GetStaticIntField(cls, field);
+  env->DeleteLocalRef(cls);
+  return ret;
+}
+
+bool doesGetObjectRefTypeWork() {
+  auto level = getAndroidApiLevel();
+  return level >= 14;
+}
+
+#else
+
+bool doesGetObjectRefTypeWork() {
+  auto jni_version = Environment::current()->GetVersion();
+  return jni_version >= JNI_VERSION_1_6;
+}
+
+#endif
+
+} // namespace
+
+bool isObjectRefType(jobject reference, jobjectRefType refType) {
+  // null-check first so that we short-circuit during (safe) global
+  // constructors, where we won't have an Environment::current() yet
+  if (!reference) {
+    return true;
+  }
+
+  static bool getObjectRefTypeWorks = doesGetObjectRefTypeWork();
+
+  return !getObjectRefTypeWorks ||
+      Environment::current()->GetObjectRefType(reference) == refType;
+}
+
+} // namespace jni
+} // namespace facebook

lib/fb/src/main/cpp/jni/detail/utf8.cpp

@@ -4,11 +4,9 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
-#include <jni/LocalString.h>
+#include <fbjni/detail/utf8.h>
-#include <fb/Environment.h>
-#include <fb/assert.h>
 
-#include <vector>
+#include <fbjni/detail/Log.h>
 
 namespace facebook {
 namespace jni {
@@ -22,7 +20,9 @@ const uint16_t kUtf16HighSubHighBoundary  = 0xDC00;
 const uint16_t kUtf16LowSubHighBoundary   = 0xE000;
 
 inline void encode3ByteUTF8(char32_t code, uint8_t* out) {
-  FBASSERTMSGF((code & 0xffff0000) == 0, "3 byte utf-8 encodings only valid for up to 16 bits");
+  if ((code & 0xffff0000) != 0) {
+    FBJNI_LOGF("3 byte utf-8 encodings only valid for up to 16 bits");
+  }
 
   out[0] = 0xE0 | (code >> 12);
   out[1] = 0x80 | ((code >> 6) & 0x3F);
@@ -36,7 +36,9 @@ inline char32_t decode3ByteUTF8(const uint8_t* in) {
 }
 
 inline void encode4ByteUTF8(char32_t code, std::string& out, size_t offset) {
-  FBASSERTMSGF((code & 0xfff80000) == 0, "4 byte utf-8 encodings only valid for up to 21 bits");
+  if ((code & 0xfff80000) != 0) {
+    FBJNI_LOGF("4 byte utf-8 encodings only valid for up to 21 bits");
+  }
 
   out[offset] =     (char) (0xF0 | (code >> 18));
   out[offset + 1] = (char) (0x80 | ((code >> 12) & 0x3F));
@@ -100,9 +102,13 @@ void utf8ToModifiedUTF8(const uint8_t* utf8, size_t len, uint8_t* modified, size
 {
   size_t j = 0;
   for (size_t i = 0; i < len; ) {
-    FBASSERTMSGF(j < modifiedBufLen, "output buffer is too short");
+    if (j >= modifiedBufLen) {
+      FBJNI_LOGF("output buffer is too short");
+    }
     if (utf8[i] == 0) {
-      FBASSERTMSGF(j + 1 < modifiedBufLen, "output buffer is too short");
+      if (j + 1 >= modifiedBufLen) {
+        FBJNI_LOGF("output buffer is too short");
+      }
       modified[j] = 0xc0;
       modified[j + 1] = 0x80;
       i += 1;
@@ -142,14 +148,18 @@ void utf8ToModifiedUTF8(const uint8_t* utf8, size_t len, uint8_t* modified, size
     }
 
     // encode each as a 3 byte surrogate value
-    FBASSERTMSGF(j + 5 < modifiedBufLen, "output buffer is too short");
+    if (j + 5 >= modifiedBufLen) {
+      FBJNI_LOGF("output buffer is too short");
+    }
     encode3ByteUTF8(first, modified + j);
     encode3ByteUTF8(second, modified + j + 3);
     i += 4;
     j += 6;
   }
 
-  FBASSERTMSGF(j < modifiedBufLen, "output buffer is too short");
+  if (j >= modifiedBufLen) {
+    FBJNI_LOGF("output buffer is too short");
+  }
   modified[j++] = '\0';
 }
 
@@ -264,46 +274,5 @@ std::string utf16toUTF8(const uint16_t* utf16String, size_t utf16StringLen) noex
 }
 
 }
-
-LocalString::LocalString(const std::string& str)
-{
-  size_t modlen = detail::modifiedLength(str);
-  if (modlen == str.size()) {
-    // no supplementary characters, build jstring from input buffer
-    m_string = Environment::current()->NewStringUTF(str.data());
-    return;
-  }
-  auto modified = std::vector<char>(modlen + 1); // allocate extra byte for \0
-  detail::utf8ToModifiedUTF8(
-    reinterpret_cast<const uint8_t*>(str.data()), str.size(),
-    reinterpret_cast<uint8_t*>(modified.data()), modified.size());
-  m_string = Environment::current()->NewStringUTF(modified.data());
 }
-
-LocalString::LocalString(const char* str)
-{
-  size_t len;
-  size_t modlen = detail::modifiedLength(reinterpret_cast<const uint8_t*>(str), &len);
-  if (modlen == len) {
-    // no supplementary characters, build jstring from input buffer
-    m_string = Environment::current()->NewStringUTF(str);
-    return;
-  }
-  auto modified = std::vector<char>(modlen + 1); // allocate extra byte for \0
-  detail::utf8ToModifiedUTF8(
-    reinterpret_cast<const uint8_t*>(str), len,
-    reinterpret_cast<uint8_t*>(modified.data()), modified.size());
-  m_string = Environment::current()->NewStringUTF(modified.data());
 }
-
-LocalString::~LocalString() {
-  Environment::current()->DeleteLocalRef(m_string);
-}
-
-std::string fromJString(JNIEnv* env, jstring str) {
-  auto utf16String = JStringUtf16Extractor(env, str);
-  auto length = env->GetStringLength(str);
-  return detail::utf16toUTF8(utf16String, length);
-}
-
-} }

lib/fb/src/main/cpp/jni/fbjni.cpp

@@ -4,36 +4,35 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
-#include <fb/fbjni.h>
+#include <fbjni/fbjni.h>
 
 #include <mutex>
 #include <vector>
-#include <jni/LocalString.h>
+
-#include <fb/log.h>
+#include <fbjni/detail/utf8.h>
 
 namespace facebook {
 namespace jni {
 
 jint initialize(JavaVM* vm, std::function<void()>&& init_fn) noexcept {
-  static std::once_flag flag{};
   // TODO (t7832883): DTRT when we have exception pointers
   static auto error_msg = std::string{"Failed to initialize fbjni"};
-  static auto error_occured = false;
+  static bool error_occured = [vm] {
-
+      bool retVal = false;
-  std::call_once(flag, [vm] {
       try {
         Environment::initialize(vm);
       } catch (std::exception& ex) {
-      error_occured = true;
+        retVal = true;
         try {
           error_msg = std::string{"Failed to initialize fbjni: "} + ex.what();
         } catch (...) {
           // Ignore, we already have a fall back message
         }
       } catch (...) {
-      error_occured = true;
+        retVal = true;
       }
-  });
+      return retVal;
+    }();
 
   try {
     if (error_occured) {
@@ -42,7 +41,7 @@ jint initialize(JavaVM* vm, std::function<void()>&& init_fn) noexcept {
 
     init_fn();
   } catch (const std::exception& e) {
-    FBLOGE("error %s", e.what());
+    FBJNI_LOGE("error %s", e.what());
     translatePendingCppExceptionToJavaException();
   } catch (...) {
     translatePendingCppExceptionToJavaException();
@@ -52,43 +51,54 @@ jint initialize(JavaVM* vm, std::function<void()>&& init_fn) noexcept {
   return JNI_VERSION_1_6;
 }
 
-alias_ref<JClass> findClassStatic(const char* name) {
+namespace detail {
-  const auto env = internal::getEnv();
+
+jclass findClass(JNIEnv* env, const char* name) {
   if (!env) {
     throw std::runtime_error("Unable to retrieve JNIEnv*.");
   }
-  auto cls = env->FindClass(name);
+  jclass cls = env->FindClass(name);
   FACEBOOK_JNI_THROW_EXCEPTION_IF(!cls);
-  auto leaking_ref = (jclass)env->NewGlobalRef(cls);
+  return cls;
-  FACEBOOK_JNI_THROW_EXCEPTION_IF(!leaking_ref);
+}
-  return wrap_alias(leaking_ref);
+
 }
 
 local_ref<JClass> findClassLocal(const char* name) {
-  const auto env = internal::getEnv();
+  return adopt_local(detail::findClass(detail::currentOrNull(), name));
-  if (!env) {
+}
-    throw std::runtime_error("Unable to retrieve JNIEnv*.");
+
-  }
+alias_ref<JClass> findClassStatic(const char* name) {
-  auto cls = env->FindClass(name);
+  JNIEnv* env = detail::currentOrNull();
-  FACEBOOK_JNI_THROW_EXCEPTION_IF(!cls);
+  auto cls = adopt_local(detail::findClass(env, name));
-  return adopt_local(cls);
+  auto leaking_ref = (jclass)env->NewGlobalRef(cls.get());
+  FACEBOOK_JNI_THROW_EXCEPTION_IF(!leaking_ref);
+  return wrap_alias(leaking_ref);
 }
 
 
 // jstring /////////////////////////////////////////////////////////////////////////////////////////
 
 std::string JString::toStdString() const {
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   auto utf16String = JStringUtf16Extractor(env, self());
-  auto length = env->GetStringLength(self());
+  return detail::utf16toUTF8(utf16String.chars(), utf16String.length());
-  return detail::utf16toUTF8(utf16String, length);
+}
+
+std::u16string JString::toU16String() const {
+  const auto env = Environment::current();
+  auto utf16String = JStringUtf16Extractor(env, self());
+  if (!utf16String.chars() || utf16String.length() == 0) {
+    return {};
+  }
+  return std::u16string(reinterpret_cast<const char16_t*>(utf16String.chars()), utf16String.length());
 }
 
 local_ref<JString> make_jstring(const char* utf8) {
   if (!utf8) {
     return {};
   }
-  const auto env = internal::getEnv();
+  const auto env = Environment::current();
   size_t len;
   size_t modlen = detail::modifiedLength(reinterpret_cast<const uint8_t*>(utf8), &len);
   jstring result;
@@ -111,6 +121,18 @@ local_ref<JString> make_jstring(const char* utf8) {
   return adopt_local(result);
 }
 
+local_ref<JString> make_jstring(const std::u16string& utf16) {
+  if (utf16.empty()) {
+    return {};
+  }
+  const auto env = Environment::current();
+  static_assert(
+      sizeof(jchar) == sizeof(std::u16string::value_type),
+      "Expecting jchar to be the same size as std::u16string::CharT");
+  jstring result = env->NewString(reinterpret_cast<const jchar*>(utf16.c_str()), utf16.size());
+  FACEBOOK_JNI_THROW_PENDING_EXCEPTION();
+  return adopt_local(result);
+}
 
 // JniPrimitiveArrayFunctions //////////////////////////////////////////////////////////////////////
 
@@ -119,50 +141,44 @@ local_ref<JString> make_jstring(const char* utf8) {
 #define DEFINE_PRIMITIVE_METHODS(TYPE, NAME, SMALLNAME)                        \
                                                                                \
 template<>                                                                     \
-FBEXPORT                                                                       \
 TYPE* JPrimitiveArray<TYPE ## Array>::getElements(jboolean* isCopy) {          \
-  auto env = internal::getEnv();                                               \
+  auto env = Environment::current();                                           \
   TYPE* res =  env->Get ## NAME ## ArrayElements(self(), isCopy);              \
   FACEBOOK_JNI_THROW_PENDING_EXCEPTION();                                      \
   return res;                                                                  \
 }                                                                              \
                                                                                \
 template<>                                                                     \
-FBEXPORT                                                                       \
 void JPrimitiveArray<TYPE ## Array>::releaseElements(                          \
     TYPE* elements, jint mode) {                                               \
-  auto env = internal::getEnv();                                               \
+  auto env = Environment::current();                                           \
   env->Release ## NAME ## ArrayElements(self(), elements, mode);               \
   FACEBOOK_JNI_THROW_PENDING_EXCEPTION();                                      \
 }                                                                              \
                                                                                \
 template<>                                                                     \
-FBEXPORT                                                                       \
 void JPrimitiveArray<TYPE ## Array>::getRegion(                                \
     jsize start, jsize length, TYPE* buf) {                                    \
-  auto env = internal::getEnv();                                               \
+  auto env = Environment::current();                                           \
   env->Get ## NAME ## ArrayRegion(self(), start, length, buf);                 \
   FACEBOOK_JNI_THROW_PENDING_EXCEPTION();                                      \
 }                                                                              \
                                                                                \
 template<>                                                                     \
-FBEXPORT                                                                       \
 void JPrimitiveArray<TYPE ## Array>::setRegion(                                \
     jsize start, jsize length, const TYPE* elements) {                         \
-  auto env = internal::getEnv();                                               \
+  auto env = Environment::current();                                           \
   env->Set ## NAME ## ArrayRegion(self(), start, length, elements);            \
   FACEBOOK_JNI_THROW_PENDING_EXCEPTION();                                      \
 }                                                                              \
                                                                                \
-FBEXPORT                                                                       \
 local_ref<TYPE ## Array> make_ ## SMALLNAME ## _array(jsize size) {            \
-  auto array = internal::getEnv()->New ## NAME ## Array(size);                 \
+  auto array = Environment::current()->New ## NAME ## Array(size);             \
   FACEBOOK_JNI_THROW_EXCEPTION_IF(!array);                                     \
   return adopt_local(array);                                                   \
 }                                                                              \
                                                                                \
 template<>                                                                     \
-FBEXPORT                                                                       \
 local_ref<TYPE ## Array> JArray ## NAME::newArray(size_t count) {              \
   return make_ ## SMALLNAME ## _array(count);                                  \
 }                                                                              \
@@ -178,13 +194,37 @@ DEFINE_PRIMITIVE_METHODS(jfloat, Float, float)
 DEFINE_PRIMITIVE_METHODS(jdouble, Double, double)
 #pragma pop_macro("DEFINE_PRIMITIVE_METHODS")
 
+namespace detail {
+
+detail::BaseHybridClass* HybridDestructor::getNativePointer() {
+  static auto pointerField = javaClassStatic()->getField<jlong>("mNativePointer");
+  auto* value = reinterpret_cast<detail::BaseHybridClass*>(getFieldValue(pointerField));
+  if (!value) {
+    throwNewJavaException("java/lang/NullPointerException", "java.lang.NullPointerException");
+  }
+  return value;
+}
+
+void HybridDestructor::setNativePointer(
+    std::unique_ptr<detail::BaseHybridClass> new_value) {
+  static auto pointerField = javaClassStatic()->getField<jlong>("mNativePointer");
+  auto old_value = std::unique_ptr<detail::BaseHybridClass>(
+    reinterpret_cast<detail::BaseHybridClass*>(getFieldValue(pointerField)));
+  if (new_value && old_value) {
+    FBJNI_LOGF("Attempt to set C++ native pointer twice");
+  }
+  setFieldValue(pointerField, reinterpret_cast<jlong>(new_value.release()));
+}
+
+}
+
 // Internal debug /////////////////////////////////////////////////////////////////////////////////
 
 namespace internal {
 
-FBEXPORT ReferenceStats g_reference_stats;
+ReferenceStats g_reference_stats;
 
-FBEXPORT void facebook::jni::internal::ReferenceStats::reset() noexcept {
+void facebook::jni::internal::ReferenceStats::reset() noexcept {
   locals_deleted = globals_deleted = weaks_deleted = 0;
 }
 

lib/fb/src/main/cpp/jni/jni_helpers.cpp

@@ -1,194 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include <jni.h>
-#include <stddef.h>
-#include <cstdio>
-
-#include <jni/jni_helpers.h>
-
-#define MSG_SIZE 1024
-
-namespace facebook {
-
-/**
- * Instructs the JNI environment to throw an exception.
- *
- * @param pEnv JNI environment
- * @param szClassName class name to throw
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-jint throwException(JNIEnv* pEnv, const char* szClassName, const char* szFmt, va_list va_args) {
-  char szMsg[MSG_SIZE];
-  vsnprintf(szMsg, MSG_SIZE, szFmt, va_args);
-  jclass exClass = pEnv->FindClass(szClassName);
-  return pEnv->ThrowNew(exClass, szMsg);
-}
-
-/**
- * Instructs the JNI environment to throw a NoClassDefFoundError.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-jint throwNoClassDefError(JNIEnv* pEnv, const char* szFmt, ...) {
-  va_list va_args;
-  va_start(va_args, szFmt);
-  jint ret = throwException(pEnv, "java/lang/NoClassDefFoundError", szFmt, va_args);
-  va_end(va_args);
-  return ret;
-}
-
-/**
- * Instructs the JNI environment to throw a RuntimeException.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-jint throwRuntimeException(JNIEnv* pEnv, const char* szFmt, ...) {
-  va_list va_args;
-  va_start(va_args, szFmt);
-  jint ret = throwException(pEnv, "java/lang/RuntimeException", szFmt, va_args);
-  va_end(va_args);
-  return ret;
-}
-
-/**
- * Instructs the JNI environment to throw an IllegalArgumentException.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-jint throwIllegalArgumentException(JNIEnv* pEnv, const char* szFmt, ...) {
-  va_list va_args;
-  va_start(va_args, szFmt);
-  jint ret = throwException(pEnv, "java/lang/IllegalArgumentException", szFmt, va_args);
-  va_end(va_args);
-  return ret;
-}
-
-/**
- * Instructs the JNI environment to throw an IllegalStateException.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-jint throwIllegalStateException(JNIEnv* pEnv, const char* szFmt, ...) {
-  va_list va_args;
-  va_start(va_args, szFmt);
-  jint ret = throwException(pEnv, "java/lang/IllegalStateException", szFmt, va_args);
-  va_end(va_args);
-  return ret;
-}
-
-/**
- * Instructs the JNI environment to throw an OutOfMemoryError.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-jint throwOutOfMemoryError(JNIEnv* pEnv, const char* szFmt, ...) {
-  va_list va_args;
-  va_start(va_args, szFmt);
-  jint ret = throwException(pEnv, "java/lang/OutOfMemoryError", szFmt, va_args);
-  va_end(va_args);
-  return ret;
-}
-
-/**
- * Instructs the JNI environment to throw an AssertionError.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-jint throwAssertionError(JNIEnv* pEnv, const char* szFmt, ...) {
-  va_list va_args;
-  va_start(va_args, szFmt);
-  jint ret = throwException(pEnv, "java/lang/AssertionError", szFmt, va_args);
-  va_end(va_args);
-  return ret;
-}
-
-/**
- * Instructs the JNI environment to throw an IOException.
- *
- * @param pEnv JNI environment
- * @param szFmt sprintf-style format string
- * @param ... sprintf-style args
- * @return 0 on success; a negative value on failure
- */
-jint throwIOException(JNIEnv* pEnv, const char* szFmt, ...) {
-  va_list va_args;
-  va_start(va_args, szFmt);
-  jint ret = throwException(pEnv, "java/io/IOException", szFmt, va_args);
-  va_end(va_args);
-  return ret;
-}
-
-/**
- * Finds the specified class. If it's not found, instructs the JNI environment to throw an
- * exception.
- *
- * @param pEnv JNI environment
- * @param szClassName the classname to find in JNI format (e.g. "java/lang/String")
- * @return the class or NULL if not found (in which case a pending exception will be queued). This
- *     returns a global reference (JNIEnv::NewGlobalRef).
- */
-jclass findClassOrThrow(JNIEnv* pEnv, const char* szClassName) {
-  jclass clazz = pEnv->FindClass(szClassName);
-  if (!clazz) {
-    return NULL;
-  }
-  return (jclass) pEnv->NewGlobalRef(clazz);
-}
-
-/**
- * Finds the specified field of the specified class. If it's not found, instructs the JNI
- * environment to throw an exception.
- *
- * @param pEnv JNI environment
- * @param clazz the class to lookup the field in
- * @param szFieldName the name of the field to find
- * @param szSig the signature of the field
- * @return the field or NULL if not found (in which case a pending exception will be queued)
- */
-jfieldID getFieldIdOrThrow(JNIEnv* pEnv, jclass clazz, const char* szFieldName, const char* szSig) {
-  return pEnv->GetFieldID(clazz, szFieldName, szSig);
-}
-
-/**
- * Finds the specified method of the specified class. If it's not found, instructs the JNI
- * environment to throw an exception.
- *
- * @param pEnv JNI environment
- * @param clazz the class to lookup the method in
- * @param szMethodName the name of the method to find
- * @param szSig the signature of the method
- * @return the method or NULL if not found (in which case a pending exception will be queued)
- */
-jmethodID getMethodIdOrThrow(
-    JNIEnv* pEnv,
-    jclass clazz,
-    const char* szMethodName,
-    const char* szSig) {
-  return pEnv->GetMethodID(clazz, szMethodName, szSig);
-}
-
-} // namespace facebook

lib/fb/src/main/cpp/log.cpp

@@ -1,97 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include <fb/log.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <string.h>
-
-#define LOG_BUFFER_SIZE 4096
-static LogHandler gLogHandler;
-
-void setLogHandler(LogHandler logHandler) {
-  gLogHandler = logHandler;
-}
-
-int fb_printLog(int prio, const char *tag,  const char *fmt, ...) {
-  char logBuffer[LOG_BUFFER_SIZE];
-
-  va_list va_args;
-  va_start(va_args, fmt);
-  int result = vsnprintf(logBuffer, sizeof(logBuffer), fmt, va_args);
-  va_end(va_args);
-  if (gLogHandler != NULL) {
-      gLogHandler(prio, tag, logBuffer);
-  }
-  __android_log_write(prio, tag, logBuffer);
-  return result;
-}
-
-void logPrintByDelims(int priority, const char* tag, const char* delims,
-        const char* msg, ...)
-{
-    va_list ap;
-    char buf[32768];
-    char* context;
-    char* tok;
-
-    va_start(ap, msg);
-    vsnprintf(buf, sizeof(buf), msg, ap);
-    va_end(ap);
-
-    tok = strtok_r(buf, delims, &context);
-
-    if (!tok) {
-        return;
-    }
-
-    do {
-        __android_log_write(priority, tag, tok);
-    } while ((tok = strtok_r(NULL, delims, &context)));
-}
-
-#ifndef ANDROID
-
-// Implementations of the basic android logging functions for non-android platforms.
-
-static char logTagChar(int prio) {
-  switch (prio) {
-    default:
-    case ANDROID_LOG_UNKNOWN:
-    case ANDROID_LOG_DEFAULT:
-    case ANDROID_LOG_SILENT:
-      return ' ';
-    case ANDROID_LOG_VERBOSE:
-      return 'V';
-    case ANDROID_LOG_DEBUG:
-      return 'D';
-    case ANDROID_LOG_INFO:
-      return 'I';
-    case ANDROID_LOG_WARN:
-      return 'W';
-    case ANDROID_LOG_ERROR:
-      return 'E';
-    case ANDROID_LOG_FATAL:
-      return 'F';
-  }
-}
-
-int __android_log_write(int prio, const char *tag, const char *text) {
-  return fprintf(stderr, "[%c/%.16s] %s\n", logTagChar(prio), tag, text);
-}
-
-int __android_log_print(int prio, const char *tag,  const char *fmt, ...) {
-  va_list ap;
-  va_start(ap, fmt);
-
-  int res = fprintf(stderr, "[%c/%.16s] ", logTagChar(prio), tag);
-  res += vfprintf(stderr, "%s\n", ap);
-
-  va_end(ap);
-  return res;
-}
-
-#endif

lib/fb/src/main/cpp/lyra/cxa_throw.cpp

@@ -0,0 +1,106 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <atomic>
+#include <stdexcept>
+#include <cxxabi.h>
+#include <unwind.h>
+#include <cassert>
+
+#include <lyra/lyra_exceptions.h>
+
+namespace facebook {
+namespace lyra {
+
+namespace {
+std::atomic<bool> enableBacktraces{true};
+}
+
+void enableCxaThrowHookBacktraces(bool enable) {
+  enableBacktraces.store(enable, std::memory_order_relaxed);
+}
+
+[[gnu::noreturn]] void (*original_cxa_throw)(void*, const std::type_info*, void (*) (void *));
+
+#if defined(_LIBCPP_VERSION)
+[[noreturn]] void cxa_throw(void* obj, const std::type_info* type, void (*destructor) (void *)) {
+  // lyra doesn't have support yet for libc++.
+  original_cxa_throw(obj, type, destructor);
+}
+#else
+
+using namespace detail;
+
+namespace {
+
+const auto traceHolderType =
+  static_cast<const abi::__class_type_info*>(&typeid(ExceptionTraceHolder));
+
+// lyra's __cxa_throw attaches stack trace information to thrown exceptions. It basically does:
+//   1. capture stack trace
+//   2. construct a new type_info struct that:
+//     a. holds the ExceptionTraceHolder
+//     b. supports upcasting to lyra::ExceptionTraceHolder* (by just returning the holder member)
+//     c. acts like the original exception type_info otherwise
+//   3. call original __cxa_throw() with original exception pointer, the
+//      HijackedExceptionTypeInfo, and HijackedExceptionTypeInfo::destructor
+//      (which will both delete the constructed type info and call the original
+//      destructor).
+struct HijackedExceptionTypeInfo : public abi::__class_type_info {
+  HijackedExceptionTypeInfo(void* obj, const std::type_info* base, void(*destructor)(void*))
+      : abi::__class_type_info{base->name()}, base_{base}, orig_dest_{destructor} {
+  }
+
+  bool __is_pointer_p() const override {
+    return base_->__is_pointer_p();
+  }
+
+  bool __is_function_p() const override {
+    return base_->__is_function_p();
+  }
+
+  bool __do_catch(const type_info *__thr_type, void **__thr_obj, unsigned __outer) const override {
+    return base_->__do_catch(__thr_type, __thr_obj, __outer);
+  }
+
+  bool __do_upcast(const abi::__class_type_info *__target, void **__obj_ptr) const override {
+    if (__target == traceHolderType) {
+      *__obj_ptr = (void*)&stack_;
+      return true;
+    }
+    return base_->__do_upcast(__target, __obj_ptr);
+  }
+
+  static void destructor(void* obj) {
+    auto exc_ptr = reinterpret_cast<std::exception_ptr*>(&obj);
+    auto info = reinterpret_cast<const::std::type_info*>(exc_ptr->__cxa_exception_type());
+    auto mutable_info = static_cast<HijackedExceptionTypeInfo*>(const_cast<std::type_info*>(info));
+    mutable_info->orig_dest_(obj);
+    delete mutable_info;
+  }
+
+ private:
+  const std::type_info* base_;
+  void (*orig_dest_)(void*);
+  ExceptionTraceHolder stack_;
+};
+
+} // namespace
+
+[[noreturn]] void cxa_throw(void* obj, const std::type_info* type, void (*destructor) (void *)) {
+  if (enableBacktraces.load(std::memory_order_relaxed)) {
+    if (!type->__do_upcast(traceHolderType, &obj)) {
+      type = new HijackedExceptionTypeInfo(obj, type, destructor);
+      destructor = HijackedExceptionTypeInfo::destructor;
+    }
+  }
+  original_cxa_throw(obj, type, destructor);
+}
+
+#endif // libc++
+
+} // namespace lyra
+} // namespace facebook

lib/fb/src/main/cpp/lyra/lyra.cpp

@@ -4,15 +4,20 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
-#include <fb/lyra.h>
+#include <lyra/lyra.h>
 
+#include <atomic>
 #include <ios>
+#include <ostream>
+#include <iomanip>
 #include <memory>
 #include <vector>
 
 #include <dlfcn.h>
 #include <unwind.h>
 
+#include <fbjni/detail/Log.h>
+
 using namespace std;
 
 namespace facebook {
@@ -67,6 +72,27 @@ void captureBacktrace(size_t skip, vector<InstructionPointer>& stackTrace) {
   BacktraceState state = {skip, stackTrace};
   _Unwind_Backtrace(unwindCallback, &state);
 }
+
+// this is a pointer to a function
+std::atomic<LibraryIdentifierFunctionType> gLibraryIdentifierFunction{nullptr};
+
+}
+
+void setLibraryIdentifierFunction(LibraryIdentifierFunctionType func) {
+  gLibraryIdentifierFunction.store(func, std::memory_order_relaxed);
+}
+
+std::string StackTraceElement::buildId() const {
+  if (!hasBuildId_) {
+    auto getBuildId = gLibraryIdentifierFunction.load(std::memory_order_relaxed);
+    if (getBuildId) {
+      buildId_ = getBuildId(libraryName());
+    } else {
+      buildId_ = "<unimplemented>";
+    }
+    hasBuildId_ = true;
+  }
+  return buildId_;
 }
 
 void getStackTrace(vector<InstructionPointer>& stackTrace, size_t skip) {
@@ -93,7 +119,6 @@ void getStackTraceSymbols(vector<StackTraceElement>& symbols,
 ostream& operator<<(ostream& out, const StackTraceElement& elm) {
   IosFlagsSaver flags{out};
 
-  // TODO(t10748683): Add build id to the output
   out << "{dso=" << elm.libraryName() << " offset=" << hex
       << showbase << elm.libraryOffset();
 
@@ -101,7 +126,7 @@ ostream& operator<<(ostream& out, const StackTraceElement& elm) {
     out << " func=" << elm.functionName() << "()+" << elm.functionOffset();
   }
 
-  out << " build-id=" << hex << setw(8) << 0
+  out << " build-id=" << hex << setw(8) << elm.buildId()
       << "}";
 
   return out;
@@ -120,5 +145,28 @@ ostream& operator<<(ostream& out, const vector<StackTraceElement>& trace) {
 
   return out;
 }
+
+void logStackTrace(const vector<StackTraceElement>& trace) {
+  auto i = 0;
+  FBJNI_LOGE("Backtrace:");
+  for (auto& elm : trace) {
+    if (!elm.functionName().empty()) {
+      FBJNI_LOGE("    #%02d |lyra|{dso=%s offset=%#x func=%s+%#x build-id=%s}",
+          i++,
+          elm.libraryName().c_str(),
+          elm.libraryOffset(),
+          elm.functionName().c_str(),
+          elm.functionOffset(),
+          elm.buildId().c_str());
+    } else {
+      FBJNI_LOGE("    #%02d |lyra|{dso=%s offset=%#x build-id=%s}",
+          i++,
+          elm.libraryName().c_str(),
+          elm.libraryOffset(),
+          elm.buildId().c_str());
+    }
+  }
+}
+
 }
 }

lib/fb/src/main/cpp/lyra/lyra_breakpad.cpp

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <lyra/lyra.h>
+
+namespace facebook {
+namespace lyra {
+
+/**
+ * This can be overridden by an implementation capable of looking up
+ * the breakpad id for logging purposes.
+*/
+__attribute__((weak))
+std::string getBreakpadId(const std::string& library) {
+  return "<unimplemented>";
+}
+
+}
+}

lib/fb/src/main/cpp/lyra/lyra_exceptions.cpp

@@ -0,0 +1,88 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <lyra/lyra_exceptions.h>
+
+#include <cstdlib>
+#include <exception>
+#include <sstream>
+#include <typeinfo>
+
+#include <fbjni/detail/Log.h>
+
+namespace facebook {
+namespace lyra {
+
+using namespace detail;
+
+namespace {
+std::terminate_handler gTerminateHandler;
+
+const ExceptionTraceHolder* getExceptionTraceHolder(std::exception_ptr ptr) {
+  try {
+    std::rethrow_exception(ptr);
+  } catch (const ExceptionTraceHolder& holder) {
+    return &holder;
+  } catch (...) {
+    return nullptr;
+  }
+}
+
+void logExceptionAndAbort() {
+  if (auto ptr = std::current_exception()) {
+    FBJNI_LOGE("Uncaught exception: %s", toString(ptr).c_str());
+    auto trace = getExceptionTraceHolder(ptr);
+    if (trace) {
+      logStackTrace(getStackTraceSymbols(trace->stackTrace_));
+    }
+  }
+  if (gTerminateHandler) {
+    gTerminateHandler();
+  } else {
+    FBJNI_LOGF("Uncaught exception and no gTerminateHandler set");
+  }
+}
+
+const std::vector<InstructionPointer> emptyTrace;
+} // namespace
+
+ExceptionTraceHolder::~ExceptionTraceHolder() {}
+
+detail::ExceptionTraceHolder::ExceptionTraceHolder() {
+  // TODO(cjhopman): This should be done more safely (i.e. use preallocated space, etc.).
+  stackTrace_.reserve(128);
+  getStackTrace(stackTrace_, 1);
+}
+
+
+void ensureRegisteredTerminateHandler() {
+  static auto initializer = (gTerminateHandler = std::set_terminate(logExceptionAndAbort));
+  (void)initializer;
+}
+
+const std::vector<InstructionPointer>& getExceptionTrace(std::exception_ptr ptr) {
+  auto holder = getExceptionTraceHolder(ptr);
+  return holder ? holder->stackTrace_ : emptyTrace;
+}
+
+std::string toString(std::exception_ptr ptr) {
+  if (!ptr) {
+    return "No exception";
+  }
+
+  try {
+    std::rethrow_exception(ptr);
+  } catch (std::exception& e) {
+    std::stringstream ss;
+    ss << typeid(e).name() << ": " << e.what();
+    return ss.str();
+  } catch (...) {
+    return "Unknown exception";
+  }
+}
+
+}
+}

lib/fb/src/main/cpp/onload.cpp

@@ -1,28 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the LICENSE
- * file in the root directory of this source tree.
- */
-#include <jni.h>
-#ifndef DISABLE_CPUCAP
-#include <fb/CpuCapabilities.h>
-#endif
-#include <fb/fbjni.h>
-
-using namespace facebook::jni;
-
-void initialize_xplatinit();
-void initialize_fbjni();
-
-JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
-  return facebook::jni::initialize(vm, [] {
-    initialize_fbjni();
-#ifndef DISABLE_XPLAT
-    initialize_xplatinit();
-#endif
-#ifndef DISABLE_CPUCAP
-    initialize_cpucapabilities();
-#endif
-  });
-}

lib/fb/src/main/java/com/facebook/jni/Countable.java

@@ -1,30 +0,0 @@
-// Copyright 2004-present Facebook. All Rights Reserved.
-
-package com.facebook.jni;
-
-import com.facebook.proguard.annotations.DoNotStrip;
-
-/**
- * A Java Object that has native memory allocated corresponding to this instance.
- *
- * NB: THREAD SAFETY (this comment also exists at Countable.cpp)
- *
- * {@link #dispose} deletes the corresponding native object on whatever thread the method is called
- * on. In the common case when this is called by Countable#finalize(), this will be called on the
- * system finalizer thread. If you manually call dispose on the Java object, the native object
- * will be deleted synchronously on that thread.
- */
-@DoNotStrip
-public class Countable {
-
-  // Private C++ instance
-  @DoNotStrip
-  private long mInstance = 0;
-
-  public native void dispose();
-
-  protected void finalize() throws Throwable {
-    dispose();
-    super.finalize();
-  }
-}

lib/fb/src/main/java/com/facebook/jni/CppException.java

@@ -1,13 +1,12 @@
-/*
+/**
  * Copyright (c) Facebook, Inc. and its affiliates.
  *
- * This source code is licensed under the MIT license found in the
+ * This source code is licensed under the MIT license found in the LICENSE
- * LICENSE file in the root directory of this source tree.
+ * file in the root directory of this source tree.
  */
-
 package com.facebook.jni;
 
-import com.facebook.proguard.annotations.DoNotStrip;
+import com.facebook.jni.annotations.DoNotStrip;
 
 @DoNotStrip
 public class CppException extends RuntimeException {

lib/fb/src/main/java/com/facebook/jni/CppSystemErrorException.java

@@ -1,13 +1,12 @@
-/*
+/**
  * Copyright (c) Facebook, Inc. and its affiliates.
  *
- * This source code is licensed under the MIT license found in the
+ * This source code is licensed under the MIT license found in the LICENSE
- * LICENSE file in the root directory of this source tree.
+ * file in the root directory of this source tree.
  */
-
 package com.facebook.jni;
 
-import com.facebook.proguard.annotations.DoNotStrip;
+import com.facebook.jni.annotations.DoNotStrip;
 
 @DoNotStrip
 public class CppSystemErrorException extends CppException {

lib/fb/src/main/java/com/facebook/jni/DestructorThread.java

@@ -0,0 +1,138 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+package com.facebook.jni;
+
+import java.lang.ref.PhantomReference;
+import java.lang.ref.ReferenceQueue;
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * A thread which invokes the "destruct" routine for objects after they have been garbage collected.
+ *
+ * <p>An object which needs to be destructed should create a static subclass of {@link Destructor}.
+ * Once the referent object is garbage collected, the DestructorThread will callback to the {@link
+ * Destructor#destruct()} method.
+ *
+ * <p>The underlying thread in DestructorThread starts when the first Destructor is constructed and
+ * then runs indefinitely.
+ */
+public class DestructorThread {
+
+  /**
+   * N.B The Destructor <b>SHOULD NOT</b> refer back to its referent object either explicitly or
+   * implicitly (for example, as a non-static inner class). This will create a reference cycle where
+   * the referent object will never be garbage collected.
+   */
+  public abstract static class Destructor extends PhantomReference<Object> {
+
+    private Destructor next;
+    private Destructor previous;
+
+    public Destructor(Object referent) {
+      super(referent, sReferenceQueue);
+      sDestructorStack.push(this);
+    }
+
+    private Destructor() {
+      super(null, sReferenceQueue);
+    }
+
+    /** Callback which is invoked when the original object has been garbage collected. */
+    protected abstract void destruct();
+  }
+
+  /** A list to keep all active Destructors in memory confined to the Destructor thread. */
+  private static final DestructorList sDestructorList;
+  /** A thread safe stack where new Destructors are placed before being add to sDestructorList. */
+  private static final DestructorStack sDestructorStack;
+
+  private static final ReferenceQueue sReferenceQueue;
+  private static final Thread sThread;
+
+  static {
+    sDestructorStack = new DestructorStack();
+    sReferenceQueue = new ReferenceQueue();
+    sDestructorList = new DestructorList();
+    sThread =
+        new Thread("HybridData DestructorThread") {
+          @Override
+          public void run() {
+            while (true) {
+              try {
+                Destructor current = (Destructor) sReferenceQueue.remove();
+                current.destruct();
+
+                // If current is in the sDestructorStack,
+                // transfer all the Destructors in the stack to the list.
+                if (current.previous == null) {
+                  sDestructorStack.transferAllToList();
+                }
+
+                DestructorList.drop(current);
+              } catch (InterruptedException e) {
+                // Continue. This thread should never be terminated.
+              }
+            }
+          }
+        };
+
+    sThread.start();
+  }
+
+  private static class Terminus extends Destructor {
+    @Override
+    protected void destruct() {
+      throw new IllegalStateException("Cannot destroy Terminus Destructor.");
+    }
+  }
+
+  /** This is a thread safe, lock-free Treiber-like Stack of Destructors. */
+  private static class DestructorStack {
+    private final AtomicReference<Destructor> mHead = new AtomicReference<>();
+
+    public void push(Destructor newHead) {
+      Destructor oldHead;
+      do {
+        oldHead = mHead.get();
+        newHead.next = oldHead;
+      } while (!mHead.compareAndSet(oldHead, newHead));
+    }
+
+    public void transferAllToList() {
+      Destructor current = mHead.getAndSet(null);
+      while (current != null) {
+        Destructor next = current.next;
+        sDestructorList.enqueue(current);
+        current = next;
+      }
+    }
+  }
+
+  /** A doubly-linked list of Destructors. */
+  private static class DestructorList {
+    private final Destructor mHead;
+
+    public DestructorList() {
+      mHead = new Terminus();
+      mHead.next = new Terminus();
+      mHead.next.previous = mHead;
+    }
+
+    public void enqueue(Destructor current) {
+      current.next = mHead.next;
+      mHead.next = current;
+
+      current.next.previous = current;
+      current.previous = mHead;
+    }
+
+    private static void drop(Destructor current) {
+      current.next.previous = current.previous;
+      current.previous.next = current.next;
+    }
+  }
+}

lib/fb/src/main/java/com/facebook/jni/HybridClassBase.java

@@ -4,6 +4,9 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
-#pragma once
+package com.facebook.jni;
 
-#define FBEXPORT __attribute__((visibility("default")))
+import com.facebook.jni.annotations.DoNotStrip;
+
+@DoNotStrip
+public abstract class HybridClassBase extends HybridData {}

lib/fb/src/main/java/com/facebook/jni/HybridData.java

@@ -1,44 +1,77 @@
-// Copyright 2004-present Facebook. All Rights Reserved.
+/**
-
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
 package com.facebook.jni;
 
-import com.facebook.proguard.annotations.DoNotStrip;
+import com.facebook.jni.annotations.DoNotStrip;
+import com.facebook.soloader.SoLoader;
 
 /**
  * This object holds a native C++ member for hybrid Java/C++ objects.
  *
- * NB: THREAD SAFETY
+ * <p>NB: THREAD SAFETY
  *
- * {@link #dispose} deletes the corresponding native object on whatever thread
+ * <p>{@link #resetNative} deletes the corresponding native object synchronously on whatever thread
- * the method is called on. In the common case when this is called by
+ * the method is called on. Otherwise, deletion will occur on the {@link DestructorThread} thread.
- * HybridData#finalize(), this will be called on the system finalizer
- * thread. If you manually call resetNative() on the Java object, the C++
- * object will be deleted synchronously on that thread.
  */
 @DoNotStrip
 public class HybridData {
 
-  // Private C++ instance
+  static {
-  @DoNotStrip
+    SoLoader.loadLibrary("fbjni");
-  private long mNativePointer = 0;
+  }
+
+  @DoNotStrip private Destructor mDestructor = new Destructor(this);
 
   /**
-   * To explicitly delete the instance, call resetNative().  If the C++
+   * To explicitly delete the instance, call resetNative(). If the C++ instance is referenced after
-   * instance is referenced after this is called, a NullPointerException will
+   * this is called, a NullPointerException will be thrown. resetNative() may be called multiple
-   * be thrown.  resetNative() may be called multiple times safely.  Because
+   * times safely. Because the {@link DestructorThread} also calls resetNative, the instance will
-   * {@link #finalize} calls resetNative, the instance will not leak if this is
+   * not leak if this is not called, but timing of deletion and the thread the C++ dtor is called on
-   * not called, but timing of deletion and the thread the C++ dtor is called
+   * will be at the whim of the Java GC. If you want to control the thread and timing of the
-   * on will be at the whim of the Java GC.  If you want to control the thread
+   * destructor, you should call resetNative() explicitly.
-   * and timing of the destructor, you should call resetNative() explicitly.
    */
-  public native void resetNative();
+  public synchronized void resetNative() {
-
+    mDestructor.destruct();
-  protected void finalize() throws Throwable {
-    resetNative();
-    super.finalize();
   }
 
+  /**
+   * N.B. Thread safety. If you call isValid from a different thread than {@link #resetNative()}
+   * then be sure to do so while synchronizing on the hybrid. For example:
+   *
+   * <pre><code>
+   * synchronized(hybrid) {
+   *   if (hybrid.isValid) {
+   *     // Do stuff.
+   *   }
+   * }
+   * </code></pre>
+   */
   public boolean isValid() {
-    return mNativePointer != 0;
+    return mDestructor.mNativePointer != 0;
+  }
+
+  public static class Destructor extends DestructorThread.Destructor {
+
+    // Private C++ instance
+    @DoNotStrip private long mNativePointer;
+
+    Destructor(Object referent) {
+      super(referent);
+    }
+
+    @Override
+    protected void destruct() {
+      // When invoked from the DestructorThread instead of resetNative,
+      // the DestructorThread has exclusive ownership of the HybridData
+      // so synchronization is not necessary.
+      deleteNative(mNativePointer);
+      mNativePointer = 0;
+    }
+
+    static native void deleteNative(long pointer);
   }
 }

lib/fb/src/main/java/com/facebook/jni/IteratorHelper.java

@@ -1,31 +1,26 @@
 /**
  * Copyright (c) Facebook, Inc. and its affiliates.
  *
- * This source code is licensed under the MIT license found in the
+ * This source code is licensed under the MIT license found in the LICENSE
- * LICENSE file in the root directory of this source tree.
+ * file in the root directory of this source tree.
  */
-
 package com.facebook.jni;
 
-import com.facebook.proguard.annotations.DoNotStrip;
+import com.facebook.jni.annotations.DoNotStrip;
-
+import java.util.Iterator;
 import javax.annotation.Nullable;
 
-import java.util.Iterator;
-
 /**
- * To iterate over an Iterator from C++ requires two calls per entry: hasNext()
+ * To iterate over an Iterator from C++ requires two calls per entry: hasNext() and next(). This
- * and next().  This helper reduces it to one call and one field get per entry.
+ * helper reduces it to one call and one field get per entry. It does not use a generic argument,
- * It does not use a generic argument, since in C++, the types will be erased,
+ * since in C++, the types will be erased, anyway. This is *not* a {@link java.util.Iterator}.
- * anyway.  This is *not* a {@link java.util.Iterator}.
  */
 @DoNotStrip
 public class IteratorHelper {
   private final Iterator mIterator;
 
   // This is private, but accessed via JNI.
-  @DoNotStrip
+  @DoNotStrip private @Nullable Object mElement;
-  private @Nullable Object mElement;
 
   @DoNotStrip
   public IteratorHelper(Iterator iterator) {
@@ -38,8 +33,8 @@ public class IteratorHelper {
   }
 
   /**
-   * Moves the helper to the next entry in the map, if any.  Returns true iff
+   * Moves the helper to the next entry in the map, if any. Returns true iff there is an entry to
-   * there is an entry to read.
+   * read.
    */
   @DoNotStrip
   boolean hasNext() {

lib/fb/src/main/java/com/facebook/jni/MapIteratorHelper.java

@@ -1,24 +1,21 @@
 /**
  * Copyright (c) Facebook, Inc. and its affiliates.
  *
- * This source code is licensed under the MIT license found in the
+ * This source code is licensed under the MIT license found in the LICENSE
- * LICENSE file in the root directory of this source tree.
+ * file in the root directory of this source tree.
  */
-
 package com.facebook.jni;
 
-import javax.annotation.Nullable;
+import com.facebook.jni.annotations.DoNotStrip;
-
 import java.util.Iterator;
 import java.util.Map;
-
+import javax.annotation.Nullable;
-import com.facebook.proguard.annotations.DoNotStrip;
 
 /**
- * To iterate over a Map from C++ requires four calls per entry: hasNext(),
+ * To iterate over a Map from C++ requires four calls per entry: hasNext(), next(), getKey(),
- * next(), getKey(), getValue().  This helper reduces it to one call and two
+ * getValue(). This helper reduces it to one call and two field gets per entry. It does not use a
- * field gets per entry.  It does not use a generic argument, since in C++, the
+ * generic argument, since in C++, the types will be erased, anyway. This is *not* a {@link
- * types will be erased, anyway.  This is *not* a {@link java.util.Iterator}.
+ * java.util.Iterator}.
  */
 @DoNotStrip
 public class MapIteratorHelper {
@@ -32,8 +29,8 @@ public class MapIteratorHelper {
   }
 
   /**
-   * Moves the helper to the next entry in the map, if any.  Returns true iff
+   * Moves the helper to the next entry in the map, if any. Returns true iff there is an entry to
-   * there is an entry to read.
+   * read.
    */
   @DoNotStrip
   boolean hasNext() {

lib/fb/src/main/java/com/facebook/jni/NativeRunnable.java

@@ -1,18 +1,14 @@
 /**
  * Copyright (c) Facebook, Inc. and its affiliates.
  *
- * This source code is licensed under the MIT license found in the
+ * This source code is licensed under the MIT license found in the LICENSE
- * LICENSE file in the root directory of this source tree.
+ * file in the root directory of this source tree.
  */
-
 package com.facebook.jni;
 
-import com.facebook.jni.HybridData;
+import com.facebook.jni.annotations.DoNotStrip;
-import com.facebook.proguard.annotations.DoNotStrip;
 
-/**
+/** A Runnable that has a native run implementation. */
- * A Runnable that has a native run implementation.
- */
 @DoNotStrip
 public class NativeRunnable implements Runnable {
 

lib/fb/src/main/java/com/facebook/jni/ThreadScopeSupport.java

@@ -1,11 +1,20 @@
-// Copyright 2004-present Facebook. All Rights Reserved.
+/**
-
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
 package com.facebook.jni;
 
-import com.facebook.proguard.annotations.DoNotStrip;
+import com.facebook.jni.annotations.DoNotStrip;
+import com.facebook.soloader.SoLoader;
 
 @DoNotStrip
 public class ThreadScopeSupport {
+  static {
+    SoLoader.loadLibrary("fbjni");
+  }
+
   // This is just used for ThreadScope::withClassLoader to have a java function
   // in the stack so that jni has access to the correct classloader.
   @DoNotStrip

lib/fb/src/main/java/com/facebook/jni/UnknownCppException.java

@@ -1,13 +1,12 @@
-/*
+/**
  * Copyright (c) Facebook, Inc. and its affiliates.
  *
- * This source code is licensed under the MIT license found in the
+ * This source code is licensed under the MIT license found in the LICENSE
- * LICENSE file in the root directory of this source tree.
+ * file in the root directory of this source tree.
  */
-
 package com.facebook.jni;
 
-import com.facebook.proguard.annotations.DoNotStrip;
+import com.facebook.jni.annotations.DoNotStrip;
 
 @DoNotStrip
 public class UnknownCppException extends CppException {

lib/fb/src/main/java/com/facebook/jni/annotations/DoNotStrip.java

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+package com.facebook.jni.annotations;
+
+import static java.lang.annotation.RetentionPolicy.CLASS;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+/**
+ * Add this annotation to a class, method, or field to instruct Proguard to not strip it out.
+ *
+ * This is useful for methods called via reflection that could appear as unused to Proguard.
+ */
+@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.CONSTRUCTOR })
+@Retention(CLASS)
+public @interface DoNotStrip {
+}

testutil/jni.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the LICENSE
  * file in the root directory of this source tree.
  */
-#include <fb/fbjni.h>
+#include <fbjni/fbjni.h>
 #include <yoga/testutil/testutil.h>
 
 using namespace facebook;