Bug 1372512 - Fix webrender Key leaks of WebRenderBridgeParent on abnormal shutdown r=kats

This bug handles abnormal client shut down case and Tab move between different windows.

Abnormal client shut down case, WebRenderBridgeParent does not receive IPC messages that are sent during WebRenderLayerManager and WebRenderBridgeChild destruction. In this case, webrender keys except keys of external images are not removed from webrender. Abnormal shut down could happen when content process was crashed or content process was killed by ContentParent if shutdown takes too long time.

In the tab move case, the WebRenderBridgeParent will need to be re-bound to a different CompositorBridgeParent and webrender, and so will need to clear all its related keys from the old webrender. This will happen in a future patch.

gfx/layers/wr/WebRenderBridgeParent.cpp

@@ -195,7 +195,10 @@ WebRenderBridgeParent::RecvAddImage(const wr::ImageKey& aImageKey,
     return IPC_OK();
   }
   MOZ_ASSERT(mApi);
+  MOZ_ASSERT(mActiveImageKeys.find(wr::AsUint64(aImageKey)) == mActiveImageKeys.end());
+
   wr::ImageDescriptor descriptor(aSize, aStride, aFormat);
+  mActiveImageKeys.insert(wr::AsUint64(aImageKey));
   mApi->AddImage(aImageKey, descriptor,
                  aBuffer.AsSlice());
 
@@ -213,7 +216,10 @@ WebRenderBridgeParent::RecvAddBlobImage(const wr::ImageKey& aImageKey,
     return IPC_OK();
   }
   MOZ_ASSERT(mApi);
+  MOZ_ASSERT(mActiveImageKeys.find(wr::AsUint64(aImageKey)) == mActiveImageKeys.end());
+
   wr::ImageDescriptor descriptor(aSize, aStride, aFormat);
+  mActiveImageKeys.insert(wr::AsUint64(aImageKey));
   mApi->AddBlobImage(aImageKey, descriptor,
                      aBuffer.AsSlice());
 
@@ -229,7 +235,10 @@ WebRenderBridgeParent::RecvAddRawFont(const wr::FontKey& aFontKey,
     return IPC_OK();
   }
   MOZ_ASSERT(mApi);
+  MOZ_ASSERT(mFontKeys.find(wr::AsUint64(aFontKey)) == mFontKeys.end());
+
   auto slice = aBuffer.AsSlice();
+  mFontKeys.insert(wr::AsUint64(aFontKey));
   mApi->AddRawFont(aFontKey, slice, aFontIndex);
 
   return IPC_OK();
@@ -242,7 +251,14 @@ WebRenderBridgeParent::RecvDeleteFont(const wr::FontKey& aFontKey)
     return IPC_OK();
   }
   MOZ_ASSERT(mApi);
-  mApi->DeleteFont(aFontKey);
+
+  if (mFontKeys.find(wr::AsUint64(aFontKey)) != mFontKeys.end()) {
+    mFontKeys.erase(wr::AsUint64(aFontKey));
+    mApi->DeleteFont(aFontKey);
+  } else {
+    MOZ_ASSERT_UNREACHABLE("invalid FontKey");
+  }
+
   return IPC_OK();
 }
 
@@ -269,10 +285,12 @@ WebRenderBridgeParent::RecvDeleteImage(const wr::ImageKey& aImageKey)
     return IPC_OK();
   }
   MOZ_ASSERT(mApi);
-  if (mActiveKeys.Get(wr::AsUint64(aImageKey), nullptr)) {
-    mActiveKeys.Remove(wr::AsUint64(aImageKey));
+  if (mActiveImageKeys.find(wr::AsUint64(aImageKey)) != mActiveImageKeys.end()) {
+    mActiveImageKeys.erase(wr::AsUint64(aImageKey));
+    mKeysToDelete.push_back(aImageKey);
+  } else {
+    MOZ_ASSERT_UNREACHABLE("invalid ImageKey");
   }
-  mKeysToDelete.push_back(aImageKey);
   return IPC_OK();
 }
 
@@ -465,8 +483,8 @@ WebRenderBridgeParent::ProcessWebRenderParentCommands(InfallibleTArray<WebRender
         const OpAddExternalImage& op = cmd.get_OpAddExternalImage();
         Range<const wr::ImageKey> keys(&op.key(), 1);
         MOZ_ASSERT(mExternalImageIds.Get(wr::AsUint64(op.externalImageId())).get());
-        MOZ_ASSERT(!mActiveKeys.Get(wr::AsUint64(keys[0]), nullptr));
-        mActiveKeys.Put(wr::AsUint64(keys[0]), keys[0]);
+        MOZ_ASSERT(mActiveImageKeys.find(wr::AsUint64(keys[0])) == mActiveImageKeys.end());
+        mActiveImageKeys.insert(wr::AsUint64(keys[0]));
 
         RefPtr<WebRenderImageHost> host = mExternalImageIds.Get(wr::AsUint64(op.externalImageId()));
         if (!host) {
@@ -1029,10 +1047,14 @@ WebRenderBridgeParent::ClearResources()
   mApi->ClearRootDisplayList(wr::NewEpoch(mWrEpoch), mPipelineId);
   // Schedule composition to clean up Pipeline
   mCompositorScheduler->ScheduleComposition();
-  for (auto iter = mActiveKeys.Iter(); !iter.Done(); iter.Next()) {
-    mKeysToDelete.push_back(iter.Data());
-    iter.Remove();
+  for (std::unordered_set<uint64_t>::iterator iter = mFontKeys.begin(); iter != mFontKeys.end(); iter++) {
+    mApi->DeleteFont(wr::AsFontKey(*iter));
   }
+  mFontKeys.clear();
+  for (std::unordered_set<uint64_t>::iterator iter = mActiveImageKeys.begin(); iter != mActiveImageKeys.end(); iter++) {
+    mKeysToDelete.push_back(wr::AsImageKey(*iter));
+  }
+  mActiveImageKeys.clear();
   DeleteOldImages();
   for (auto iter = mExternalImageIds.Iter(); !iter.Done(); iter.Next()) {
     iter.Data()->ClearWrBridge();

gfx/layers/wr/WebRenderBridgeParent.h

@@ -247,8 +247,10 @@ private:
   RefPtr<CompositorVsyncScheduler> mCompositorScheduler;
   RefPtr<CompositorAnimationStorage> mAnimStorage;
   std::vector<wr::ImageKey> mKeysToDelete;
-  // XXX How to handle active keys of non-ExternalImages?
-  nsDataHashtable<nsUint64HashKey, wr::ImageKey> mActiveKeys;
+  // mActiveImageKeys and mFontKeys are used to avoid leaking animations when
+  // WebRenderBridgeParent is destroyed abnormally and Tab move between different windows.
+  std::unordered_set<uint64_t> mActiveImageKeys;
+  std::unordered_set<uint64_t> mFontKeys;
   // mActiveAnimations is used to avoid leaking animations when WebRenderBridgeParent is
   // destroyed abnormally and Tab move between different windows.
   std::unordered_set<uint64_t> mActiveAnimations;

gfx/webrender_bindings/WebRenderTypes.h

@@ -115,6 +115,26 @@ inline uint64_t AsUint64(const ImageKey& aId) {
         + static_cast<uint64_t>(aId.mHandle);
 }
 
+inline ImageKey AsImageKey(const uint64_t& aId) {
+  ImageKey imageKey;
+  imageKey.mNamespace = aId >> 32;
+  imageKey.mHandle = aId;
+  return imageKey;
+}
+
+// Whenever possible, use wr::FontKey instead of manipulating uint64_t.
+inline uint64_t AsUint64(const FontKey& aId) {
+  return (static_cast<uint64_t>(aId.mNamespace) << 32)
+        + static_cast<uint64_t>(aId.mHandle);
+}
+
+inline FontKey AsFontKey(const uint64_t& aId) {
+  FontKey fontKey;
+  fontKey.mNamespace = aId >> 32;
+  fontKey.mHandle = aId;
+  return fontKey;
+}
+
 // Whenever possible, use wr::PipelineId instead of manipulating uint64_t.
 inline uint64_t AsUint64(const PipelineId& aId) {
   return (static_cast<uint64_t>(aId.mNamespace) << 32)