Bug 1526213 - Enable WebRenderTextureHostWrapper for canvas r=nical

By using WebRenderTextureHostWrapper for canvas, we could avoid triggering frame build on WebRender backend if WebRenderTextureHostWrapper is only change.

Differential Revision: https://phabricator.services.mozilla.com/D19896

--HG--
extra : moz-landing-system : lando

gfx/layers/wr/AsyncImagePipelineManager.cpp

@@ -234,8 +234,7 @@ Maybe<TextureHost::ResourceUpdateOp> AsyncImagePipelineManager::UpdateImageKeys(
   // Use WebRenderTextureHostWrapper only for video.
   // And WebRenderTextureHostWrapper could be used only with
   // WebRenderTextureHost that supports NativeTexture
-  bool useWrTextureWrapper = aPipeline->mImageHost->GetAsyncRef() &&
-                             useExternalImage && wrTexture &&
+  bool useWrTextureWrapper = useExternalImage && wrTexture &&
                              wrTexture->SupportsWrNativeTexture();
 
   // The non-external image code path falls back to converting the texture into
@@ -280,13 +279,13 @@ Maybe<TextureHost::ResourceUpdateOp> AsyncImagePipelineManager::UpdateImageKeys(
     MOZ_ASSERT(canUpdate);
     // Reuse WebRenderTextureHostWrapper. With it, rendered frame could be
     // updated without batch re-creation.
-    aPipeline->mWrTextureWrapper->UpdateWebRenderTextureHost(wrTexture);
+    aPipeline->mWrTextureWrapper->UpdateWebRenderTextureHost(aMaybeFastTxn, wrTexture);
     // Ensure frame generation.
     SetWillGenerateFrame();
   } else {
     if (useWrTextureWrapper) {
       aPipeline->mWrTextureWrapper = new WebRenderTextureHostWrapper(this);
-      aPipeline->mWrTextureWrapper->UpdateWebRenderTextureHost(wrTexture);
+      aPipeline->mWrTextureWrapper->UpdateWebRenderTextureHost(aMaybeFastTxn, wrTexture);
     }
     Range<wr::ImageKey> keys(&aKeys[0], aKeys.Length());
     auto externalImageKey =

gfx/layers/wr/WebRenderTextureHostWrapper.cpp

@@ -10,10 +10,35 @@
 #include "mozilla/layers/WebRenderTextureHost.h"
 #include "mozilla/webrender/RenderTextureHostWrapper.h"
 #include "mozilla/webrender/RenderThread.h"
+#include "mozilla/webrender/WebRenderAPI.h"
+#include "mozilla/webrender/RenderThread.h"
 
 namespace mozilla {
 namespace layers {
 
+class ScheduleUpdateRenderTextureHost : public wr::NotificationHandler {
+ public:
+  ScheduleUpdateRenderTextureHost(uint64_t aSrcExternalImageId,
+                                  uint64_t aWrappedExternalImageId)
+      : mSrcExternalImageId(aSrcExternalImageId),
+        mWrappedExternalImageId(aWrappedExternalImageId) {}
+
+  virtual void Notify(wr::Checkpoint aCheckpoint) override {
+    if (aCheckpoint == wr::Checkpoint::FrameTexturesUpdated) {
+      MOZ_ASSERT(wr::RenderThread::IsInRenderThread());
+      wr::RenderThread::Get()->UpdateRenderTextureHost(
+          mSrcExternalImageId,
+          mWrappedExternalImageId);
+    } else {
+      MOZ_ASSERT(aCheckpoint == wr::Checkpoint::TransactionDropped);
+    }
+  }
+
+ protected:
+  uint64_t mSrcExternalImageId;
+  uint64_t mWrappedExternalImageId;
+};
+
 WebRenderTextureHostWrapper::WebRenderTextureHostWrapper(
     AsyncImagePipelineManager* aManager)
     : mExternalImageId(aManager->GetNextExternalImageId()) {
@@ -32,12 +57,20 @@ WebRenderTextureHostWrapper::~WebRenderTextureHostWrapper() {
 }
 
 void WebRenderTextureHostWrapper::UpdateWebRenderTextureHost(
+    wr::TransactionBuilder& aTxn,
     WebRenderTextureHost* aTextureHost) {
   MOZ_ASSERT(aTextureHost);
-  mWrTextureHost = aTextureHost;
-  wr::RenderThread::Get()->UpdateRenderTextureHost(
+
+  // AsyncImagePipelineManager is responsible of holding compositable ref of
+  // wrapped WebRenderTextureHost by using ForwardingTextureHost.
+  // ScheduleUpdateRenderTextureHost does not need to handle it.
+
+  aTxn.Notify(wr::Checkpoint::FrameTexturesUpdated,
+      MakeUnique<ScheduleUpdateRenderTextureHost>(
         wr::AsUint64(mExternalImageId),
-      wr::AsUint64(aTextureHost->GetExternalImageKey()));
+        wr::AsUint64(aTextureHost->GetExternalImageKey())));
+
+  mWrTextureHost = aTextureHost;
 }
 
 }  // namespace layers

gfx/layers/wr/WebRenderTextureHostWrapper.h

@@ -21,7 +21,8 @@ class WebRenderTextureHostWrapper {
  public:
   explicit WebRenderTextureHostWrapper(AsyncImagePipelineManager* aManager);
 
-  void UpdateWebRenderTextureHost(WebRenderTextureHost* aTextureHost);
+  void UpdateWebRenderTextureHost(wr::TransactionBuilder& aTxn,
+                                  WebRenderTextureHost* aTextureHost);
 
   wr::ExternalImageId GetExternalImageKey() { return mExternalImageId; }
 

gfx/webrender_bindings/RenderTextureHostWrapper.cpp

@@ -49,7 +49,7 @@ void RenderTextureHostWrapper::ClearCachedResources() {
 
 void RenderTextureHostWrapper::UpdateRenderTextureHost(
     RenderTextureHost* aTextureHost) {
-  MOZ_ASSERT(!mInited || RenderThread::IsInRenderThread());
+  MOZ_ASSERT(RenderThread::IsInRenderThread());
   MOZ_RELEASE_ASSERT(!mLocked);
 
   mInited = true;

gfx/webrender_bindings/RenderThread.cpp

@@ -594,6 +594,7 @@ void RenderThread::UnregisterExternalImage(uint64_t aExternalImageId) {
 void RenderThread::UpdateRenderTextureHost(uint64_t aSrcExternalImageId,
                                            uint64_t aWrappedExternalImageId) {
   MOZ_ASSERT(aSrcExternalImageId != aWrappedExternalImageId);
+  MOZ_ASSERT(RenderThread::IsInRenderThread());
 
   MutexAutoLock lock(mRenderTextureMapLock);
   if (mHasShutdown) {
@@ -611,14 +612,7 @@ void RenderThread::UpdateRenderTextureHost(uint64_t aSrcExternalImageId,
     MOZ_ASSERT_UNREACHABLE("unexpected to happen");
     return;
   }
-  if (!wrapper->IsInited()) {
   wrapper->UpdateRenderTextureHost(wrapped->second);
-    MOZ_ASSERT(wrapper->IsInited());
-  } else {
-    Loop()->PostTask(NewRunnableMethod<RenderTextureHost*>(
-        "RenderTextureHostWrapper::UpdateRenderTextureHost", wrapper,
-        &RenderTextureHostWrapper::UpdateRenderTextureHost, wrapped->second));
-  }
 }
 
 void RenderThread::UnregisterExternalImageDuringShutdown(

gfx/webrender_bindings/RenderThread.h

@@ -185,7 +185,7 @@ class RenderThread final {
   /// Can be called from any thread.
   void UnregisterExternalImage(uint64_t aExternalImageId);
 
-  /// Can be called from any thread.
+  /// Can only be called from the render thread.
   void UpdateRenderTextureHost(uint64_t aSrcExternalImageId,
                                uint64_t aWrappedExternalImageId);
 

gfx/wr/webrender/src/scene_builder.rs

@@ -580,6 +580,7 @@ impl SceneBuilder {
 
         let scene_swap_start_time = precise_time_ns();
         let has_resources_updates = !txn.resource_updates.is_empty();
+        let invalidate_rendered_frame = txn.invalidate_rendered_frame;
 
         self.tx.send(SceneBuilderResult::Transaction(txn, result_tx)).unwrap();
 
@@ -597,7 +598,7 @@ impl SceneBuilder {
                 },
                 _ => (),
             };
-        } else if has_resources_updates {
+        } else if has_resources_updates || invalidate_rendered_frame {
             if let &Some(ref hooks) = &self.hooks {
                 hooks.post_resource_update();
             }