Make Java measure thread-safe.

src/JavaTranspiler.js

@@ -26,6 +26,7 @@ function __transpileToJavaCommon(code) {
     .replace(/pos\[([^\]]+)\]/g, 'getPos($1)')
     .replace(/dim\[([^\]]+)\]/g, 'getDim($1)')
     .replace(/isUndefined/g, 'CSSConstants.isUndefined')
+    .replace(/\/\*\(java\)!([^*]+)\*\//g, '$1')
 
     // Since Java doesn't store its attributes in arrays, we need to use setters/getters to access
     // the appropriate layout/style fields

src/Layout.c

@@ -378,6 +378,7 @@ static void layoutNodeImpl(css_node_t *node, float parentMaxWidth) {
     if (isRowUndefined || isColumnUndefined) {
       css_dim_t measureDim = node->measure(
         node->context,
+        
         width
       );
       if (isRowUndefined) {

src/Layout.js

@@ -278,6 +278,7 @@ var computeLayout = (function() {
       if (isRowUndefined || isColumnUndefined) {
         var/*css_dim_t*/ measureDim = node.style.measure(
           /*(c)!node->context,*/
+          /*(java)!layoutContext.measureOutput,*/
           width
         );
         if (isRowUndefined) {
@@ -397,7 +398,7 @@ var computeLayout = (function() {
 
           // This is the main recursive call. We layout non flexible children.
           if (alreadyComputedNextLayout === 0) {
-            layoutNode(child, maxWidth);
+            layoutNode(/*(java)!layoutContext, */child, maxWidth);
           }
 
           // Absolute positioned elements do not take part of the layout, so we
@@ -472,7 +473,7 @@ var computeLayout = (function() {
             }
 
             // And we recursively call the layout algorithm for this child
-            layoutNode(child, maxWidth);
+            layoutNode(/*(java)!layoutContext, */child, maxWidth);
           }
         }
 

src/java/src/com/facebook/csslayout/CSSLayoutContext.java

@@ -0,0 +1,20 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+package com.facebook.csslayout;
+
+/**
+ * A context for holding values local to a given instance of layout computation.
+ *
+ * This is necessary for making layout thread-safe. A separate instance should
+ * be used when {@link CSSNode#calculateLayout} is called concurrently on
+ * different node hierarchies.
+ */
+public class CSSLayoutContext {
+  /*package*/ final MeasureOutput measureOutput = new MeasureOutput();
+}

src/java/src/com/facebook/csslayout/CSSNode.java

@@ -39,10 +39,6 @@ public class CSSNode {
     UP_TO_DATE,
   }
 
-  // Only one copy kept around to keep from allocating a bunch of MeasureOutput objects
-  // NOT THREAD SAFE! NOT RE-ENTRANT SAFE!
-  private static final MeasureOutput MEASURE_OUTPUT = new MeasureOutput();
-
   public static interface MeasureFunction {
 
     /**
@@ -114,22 +110,22 @@ public class CSSNode {
     return mMeasureFunction != null;
   }
 
-  /*package*/ MeasureOutput measure(float width) {
+  /*package*/ MeasureOutput measure(MeasureOutput measureOutput, float width) {
     if (!isMeasureDefined()) {
       throw new RuntimeException("Measure function isn't defined!");
     }
-    MEASURE_OUTPUT.height = CSSConstants.UNDEFINED;
+    measureOutput.height = CSSConstants.UNDEFINED;
-    MEASURE_OUTPUT.width = CSSConstants.UNDEFINED;
+    measureOutput.width = CSSConstants.UNDEFINED;
-    Assertions.assertNotNull(mMeasureFunction).measure(this, width, MEASURE_OUTPUT);
+    Assertions.assertNotNull(mMeasureFunction).measure(this, width, measureOutput);
-    return MEASURE_OUTPUT;
+    return measureOutput;
   }
 
   /**
    * Performs the actual layout and saves the results in {@link #layout}
    */
-  public void calculateLayout() {
+  public void calculateLayout(CSSLayoutContext layoutContext) {
     layout.resetResult();
-    LayoutEngine.layoutNode(this, CSSConstants.UNDEFINED);
+    LayoutEngine.layoutNode(layoutContext, this, CSSConstants.UNDEFINED);
   }
 
   /**

src/java/src/com/facebook/csslayout/LayoutEngine.java

@@ -261,13 +261,16 @@ public class LayoutEngine {
         !FloatUtil.floatsEqual(node.lastLayout.parentMaxWidth, parentMaxWidth);
   }
 
-  /*package*/ static void layoutNode(CSSNode node, float parentMaxWidth) {
+  /*package*/ static void layoutNode(
+      CSSLayoutContext layoutContext,
+      CSSNode node,
+      float parentMaxWidth) {
     if (needsRelayout(node, parentMaxWidth)) {
       node.lastLayout.requestedWidth = node.layout.width;
       node.lastLayout.requestedHeight = node.layout.height;
       node.lastLayout.parentMaxWidth = parentMaxWidth;
 
-      layoutNodeImpl(node, parentMaxWidth);
+      layoutNodeImpl(layoutContext, node, parentMaxWidth);
       node.lastLayout.copy(node.layout);
     } else {
       node.layout.copy(node.lastLayout);
@@ -276,7 +279,10 @@ public class LayoutEngine {
     node.markHasNewLayout();
   }
 
-  private static void layoutNodeImpl(CSSNode node, float parentMaxWidth) {
+  private static void layoutNodeImpl(
+      CSSLayoutContext layoutContext,
+      CSSNode node,
+      float parentMaxWidth) {
 
     for (int i = 0; i < node.getChildCount(); i++) {
       node.getChildAt(i).layout.resetResult();
@@ -324,7 +330,8 @@ public class LayoutEngine {
       // Let's not measure the text if we already know both dimensions
       if (isRowUndefined || isColumnUndefined) {
         MeasureOutput measureDim = node.measure(
-                    width
+                    layoutContext.measureOutput,
+          width
         );
         if (isRowUndefined) {
           node.layout.width = measureDim.width +
@@ -443,7 +450,7 @@ public class LayoutEngine {
   
           // This is the main recursive call. We layout non flexible children.
           if (alreadyComputedNextLayout == 0) {
-            layoutNode(child, maxWidth);
+            layoutNode(layoutContext, child, maxWidth);
           }
   
           // Absolute positioned elements do not take part of the layout, so we
@@ -518,7 +525,7 @@ public class LayoutEngine {
             }
   
             // And we recursively call the layout algorithm for this child
-            layoutNode(child, maxWidth);
+            layoutNode(layoutContext, child, maxWidth);
           }
         }
   

src/java/tests/com/facebook/csslayout/LayoutCachingTest.java

@@ -35,6 +35,7 @@ public class LayoutCachingTest {
 
   @Test
   public void testCachesFullTree() {
+    CSSLayoutContext layoutContext = new CSSLayoutContext();
     CSSNode root = new CSSNode();
     CSSNode c0 = new CSSNode();
     CSSNode c1 = new CSSNode();
@@ -43,11 +44,11 @@ public class LayoutCachingTest {
     root.addChildAt(c1, 1);
     c0.addChildAt(c0c0, 0);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     assertTreeHasNewLayout(true, root);
     markLayoutAppliedForTree(root);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     assertTrue(root.hasNewLayout());
     assertTreeHasNewLayout(false, c0);
     assertTreeHasNewLayout(false, c1);
@@ -55,6 +56,7 @@ public class LayoutCachingTest {
 
   @Test
   public void testInvalidatesCacheWhenChildAdded() {
+    CSSLayoutContext layoutContext = new CSSLayoutContext();
     CSSNode root = new CSSNode();
     CSSNode c0 = new CSSNode();
     CSSNode c1 = new CSSNode();
@@ -68,12 +70,12 @@ public class LayoutCachingTest {
     c0.addChildAt(c0c0, 0);
     c0c0.addChildAt(c1c0, 0);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     markLayoutAppliedForTree(root);
 
     c0.addChildAt(c0c1, 1);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     assertTrue(root.hasNewLayout());
     assertTrue(c0.hasNewLayout());
     assertTrue(c0c1.hasNewLayout());
@@ -86,6 +88,7 @@ public class LayoutCachingTest {
 
   @Test
   public void testInvalidatesCacheWhenEnumPropertyChanges() {
+    CSSLayoutContext layoutContext = new CSSLayoutContext();
     CSSNode root = new CSSNode();
     CSSNode c0 = new CSSNode();
     CSSNode c1 = new CSSNode();
@@ -94,11 +97,11 @@ public class LayoutCachingTest {
     root.addChildAt(c1, 1);
     c0.addChildAt(c0c0, 0);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     markLayoutAppliedForTree(root);
 
     c1.setAlignSelf(CSSAlign.CENTER);
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
 
     assertTrue(root.hasNewLayout());
     assertTrue(c1.hasNewLayout());
@@ -109,6 +112,7 @@ public class LayoutCachingTest {
 
   @Test
   public void testInvalidatesCacheWhenFloatPropertyChanges() {
+    CSSLayoutContext layoutContext = new CSSLayoutContext();
     CSSNode root = new CSSNode();
     CSSNode c0 = new CSSNode();
     CSSNode c1 = new CSSNode();
@@ -117,11 +121,11 @@ public class LayoutCachingTest {
     root.addChildAt(c1, 1);
     c0.addChildAt(c0c0, 0);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     markLayoutAppliedForTree(root);
 
     c1.setMargin(Spacing.LEFT, 10);
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
 
     assertTrue(root.hasNewLayout());
     assertTrue(c1.hasNewLayout());
@@ -132,6 +136,7 @@ public class LayoutCachingTest {
 
   @Test
   public void testInvalidatesFullTreeWhenParentWidthChanges() {
+    CSSLayoutContext layoutContext = new CSSLayoutContext();
     CSSNode root = new CSSNode();
     CSSNode c0 = new CSSNode();
     CSSNode c1 = new CSSNode();
@@ -142,11 +147,11 @@ public class LayoutCachingTest {
     c0.addChildAt(c0c0, 0);
     c1.addChildAt(c1c0, 0);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     markLayoutAppliedForTree(root);
 
     c0.setStyleWidth(200);
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
 
     assertTrue(root.hasNewLayout());
     assertTrue(c0.hasNewLayout());
@@ -158,6 +163,7 @@ public class LayoutCachingTest {
 
   @Test
   public void testDoesNotInvalidateCacheWhenPropertyIsTheSame() {
+    CSSLayoutContext layoutContext = new CSSLayoutContext();
     CSSNode root = new CSSNode();
     CSSNode c0 = new CSSNode();
     CSSNode c1 = new CSSNode();
@@ -167,11 +173,11 @@ public class LayoutCachingTest {
     c0.addChildAt(c0c0, 0);
     root.setStyleWidth(200);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     markLayoutAppliedForTree(root);
 
     root.setStyleWidth(200);
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
 
     assertTrue(root.hasNewLayout());
     assertTreeHasNewLayout(false, c0);
@@ -180,6 +186,7 @@ public class LayoutCachingTest {
 
   @Test
   public void testInvalidateCacheWhenHeightChangesPosition() {
+    CSSLayoutContext layoutContext = new CSSLayoutContext();
     CSSNode root = new CSSNode();
     CSSNode c0 = new CSSNode();
     CSSNode c1 = new CSSNode();
@@ -188,11 +195,11 @@ public class LayoutCachingTest {
     root.addChildAt(c1, 1);
     c1.addChildAt(c1c0, 0);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     markLayoutAppliedForTree(root);
 
     c0.setStyleHeight(100);
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
 
     assertTrue(root.hasNewLayout());
     assertTrue(c0.hasNewLayout());
@@ -202,6 +209,7 @@ public class LayoutCachingTest {
 
   @Test
   public void testInvalidatesOnNewMeasureFunction() {
+    CSSLayoutContext layoutContext = new CSSLayoutContext();
     CSSNode root = new CSSNode();
     CSSNode c0 = new CSSNode();
     CSSNode c1 = new CSSNode();
@@ -210,7 +218,7 @@ public class LayoutCachingTest {
     root.addChildAt(c1, 1);
     c0.addChildAt(c0c0, 0);
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
     markLayoutAppliedForTree(root);
 
     c1.setMeasureFunction(new CSSNode.MeasureFunction() {
@@ -221,7 +229,7 @@ public class LayoutCachingTest {
       }
     });
 
-    root.calculateLayout();
+    root.calculateLayout(layoutContext);
 
     assertTrue(root.hasNewLayout());
     assertTrue(c1.hasNewLayout());

src/java/tests/com/facebook/csslayout/LayoutEngineTest.java

@@ -50,7 +50,8 @@ public class LayoutEngineTest {
   }
 
   private static void test(String message, CSSNode style, CSSNode expectedLayout) {
-    style.calculateLayout();
+    CSSLayoutContext layoutContext = new CSSLayoutContext();
+    style.calculateLayout(layoutContext);
     assertLayoutsEqual(message, style, expectedLayout);
   }
 

src/transpile.js

@@ -237,6 +237,7 @@ function transpileAnnotatedJStoC(jsCode) {
     .replace(/\n {2}/g, '\n')
     .replace(/\/\*\(c\)!([^*]+)\*\//g, '$1')
     .replace(/\/[*]!([^*]+)[*]\//g, '$1')
+    .replace(/\/\*\(java\)!([^*]+)\*\//g, '')
     .split('\n').slice(1, -1).join('\n');
 }