Fix a resource race bug in PathCache

When enabled defer rendering, it will do precache for DrawPathOp.
The paint used for creating PathTask in precache just get the address
of mFilteredPaint of OpenGLRenderer. So for the following defer
operation like DrawTextOp has possibility change the mFilteredPaint
by getPaint while another WorkerThread in PathCache is using the paint
which pointed to the same address of mFilteredPaint to generate bitmap.
As a result, it will generate a wrong bitmap for generateTexture in
PathCache. To fix it, do a copy of paint when creating PathTask.

CRs-Fixed: 664244

Change-Id: I5516f5b143458b88d3573d15b7ebb34f688800c7

2 files changed, 5 insertions, 4 deletions

diff --git a/libs/hwui/PathCache.cpp b/libs/hwui/PathCache.cpp
index cf8adf8772f3..0794aecaceb6 100644
--- a/libs/hwui/PathCache.cpp
+++ b/libs/hwui/PathCache.cpp
@@ -346,7 +346,7 @@ void PathCache::PathProcessor::onProcess(const sp<Task<SkBitmap*> >& task) {
 
     float left, top, offset;
     uint32_t width, height;
-    PathCache::computePathBounds(t->path, t->paint, left, top, offset, width, height);
+    PathCache::computePathBounds(t->path, &t->paint, left, top, offset, width, height);
 
     PathTexture* texture = t->texture;
     texture->left = left;
@@ -357,7 +357,7 @@ void PathCache::PathProcessor::onProcess(const sp<Task<SkBitmap*> >& task) {
 
     if (width <= mMaxTextureSize && height <= mMaxTextureSize) {
         SkBitmap* bitmap = new SkBitmap();
-        drawPath(t->path, t->paint, *bitmap, left, top, offset, width, height);
+        drawPath(t->path, &t->paint, *bitmap, left, top, offset, width, height);
         t->setResult(bitmap);
     } else {
         texture->width = 0;
diff --git a/libs/hwui/PathCache.h b/libs/hwui/PathCache.h
index 16d20a81c199..24f88f1d0535 100644
--- a/libs/hwui/PathCache.h
+++ b/libs/hwui/PathCache.h
@@ -293,7 +293,7 @@ private:
     class PathTask: public Task<SkBitmap*> {
     public:
         PathTask(SkPath* path, SkPaint* paint, PathTexture* texture):
-            path(path), paint(paint), texture(texture) {
+            path(path), paint(*paint), texture(texture) {
         }
 
         ~PathTask() {
@@ -301,7 +301,8 @@ private:
         }
 
         SkPath* path;
-        SkPaint* paint;
+        //copied, since input paint may not be immutable
+        SkPaint paint;
         PathTexture* texture;
     };