From ec845a215e343cdb3b2e4c7b6aff7b24beb0236b Mon Sep 17 00:00:00 2001
From: John Reck <jreck@google.com>
Date: Fri, 5 Sep 2014 15:23:38 -0700
Subject: [PATCH] Fix race condition

 Bug: 17372309

 AnimationContext::startFrame() happens both with and without
 the UI thread lock. Pass the TraversalMode into it so
 that ThreadedRenderer's subclass can correctly decide
 when it is safe to push over mPendingAnimatingRenderNodes, as doing
 so outside of the lock is Very Bad.

Change-Id: Ife5dd3a2b46b0a207cd9234c159a674afdbf5efd
---
 core/jni/android_view_ThreadedRenderer.cpp | 8 +++++---
 libs/hwui/AnimationContext.cpp             | 5 ++---
 libs/hwui/AnimationContext.h               | 4 ++--
 libs/hwui/renderthread/CanvasContext.cpp   | 2 +-
 4 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/core/jni/android_view_ThreadedRenderer.cpp b/core/jni/android_view_ThreadedRenderer.cpp
index 7e6d3356d5653..a8edb77b0212e 100644
--- a/core/jni/android_view_ThreadedRenderer.cpp
+++ b/core/jni/android_view_ThreadedRenderer.cpp
@@ -158,9 +158,11 @@ public:
 
     // Marks the start of a frame, which will update the frame time and move all
     // next frame animations into the current frame
-    virtual void startFrame() {
-        mRootNode->doAttachAnimatingNodes(this);
-        AnimationContext::startFrame();
+    virtual void startFrame(TreeInfo::TraversalMode mode) {
+        if (mode == TreeInfo::MODE_FULL) {
+            mRootNode->doAttachAnimatingNodes(this);
+        }
+        AnimationContext::startFrame(mode);
     }
 
     // Runs any animations still left in mCurrentFrameAnimations
diff --git a/libs/hwui/AnimationContext.cpp b/libs/hwui/AnimationContext.cpp
index 716dcf57de2d9..a20bdae31f791 100644
--- a/libs/hwui/AnimationContext.cpp
+++ b/libs/hwui/AnimationContext.cpp
@@ -17,7 +17,6 @@
 
 #include "Animator.h"
 #include "RenderNode.h"
-#include "TreeInfo.h"
 #include "renderthread/TimeLord.h"
 
 namespace android {
@@ -34,7 +33,7 @@ AnimationContext::~AnimationContext() {
 }
 
 void AnimationContext::destroy() {
-    startFrame();
+    startFrame(TreeInfo::MODE_RT_ONLY);
     while (mCurrentFrameAnimations.mNextHandle) {
         AnimationHandle* current = mCurrentFrameAnimations.mNextHandle;
         AnimatorManager& animators = current->mRenderNode->animators();
@@ -55,7 +54,7 @@ void AnimationContext::addAnimationHandle(AnimationHandle* handle) {
     handle->insertAfter(&mNextFrameAnimations);
 }
 
-void AnimationContext::startFrame() {
+void AnimationContext::startFrame(TreeInfo::TraversalMode mode) {
     LOG_ALWAYS_FATAL_IF(mCurrentFrameAnimations.mNextHandle,
             "Missed running animations last frame!");
     AnimationHandle* head = mNextFrameAnimations.mNextHandle;
diff --git a/libs/hwui/AnimationContext.h b/libs/hwui/AnimationContext.h
index 9b3d5f486464c..909ed36a21276 100644
--- a/libs/hwui/AnimationContext.h
+++ b/libs/hwui/AnimationContext.h
@@ -20,6 +20,7 @@
 #include <utils/RefBase.h>
 #include <utils/StrongPointer.h>
 
+#include "TreeInfo.h"
 #include "renderthread/TimeLord.h"
 #include "utils/Macros.h"
 
@@ -30,7 +31,6 @@ class AnimationContext;
 class AnimationListener;
 class BaseRenderNodeAnimator;
 class RenderNode;
-class TreeInfo;
 
 /*
  * AnimationHandle is several classes merged into one.
@@ -90,7 +90,7 @@ public:
 
     // Marks the start of a frame, which will update the frame time and move all
     // next frame animations into the current frame
-    ANDROID_API virtual void startFrame();
+    ANDROID_API virtual void startFrame(TreeInfo::TraversalMode mode);
 
     // Runs any animations still left in mCurrentFrameAnimations that were not run
     // as part of the standard RenderNode:prepareTree pass.
diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index 4129a89b6ef86..5e6796c2b406f 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -150,7 +150,7 @@ void CanvasContext::prepareTree(TreeInfo& info) {
     if (mPrefetechedLayers.size() && info.mode == TreeInfo::MODE_FULL) {
         info.canvasContext = this;
     }
-    mAnimationContext->startFrame();
+    mAnimationContext->startFrame(info.mode);
     mRootRenderNode->prepareTree(info);
     mAnimationContext->runRemainingAnimations(info);