cc: Stop blocking the main thread in CreateAndInitializeOutputSurface.

cc/trees/thread_proxy.cc

Index: cc/trees/thread_proxy.cc
diff --git a/cc/trees/thread_proxy.cc b/cc/trees/thread_proxy.cc
index b7c19d06109a515fc7f4aaabf3a887afead2ae3c..525b44290c6c0a3f9247027778ca04fce018d3a1 100644
--- a/cc/trees/thread_proxy.cc
+++ b/cc/trees/thread_proxy.cc
@@ -194,40 +194,59 @@ void ThreadProxy::UpdateBackgroundAnimateTicking() {
     impl().animations_frozen_until_next_draw = false;
 }
 
-void ThreadProxy::DoCreateAndInitializeOutputSurface() {
+void ThreadProxy::DidLoseOutputSurface() {
+  TRACE_EVENT0("cc", "ThreadProxy::DidLoseOutputSurface");
+  DCHECK(IsMainThread());
+  layer_tree_host()->DidLoseOutputSurface();
+
+  {
+    DebugScopedSetMainThreadBlocked main_thread_blocked(this);
+
+    // Return lost resources to their owners immediately.
+    BlockingTaskRunner::CapturePostTasks blocked;
+
+    CompletionEvent completion;
+    Proxy::ImplThreadTaskRunner()->PostTask(
+        FROM_HERE,
+        base::Bind(&ThreadProxy::DeleteContentsTexturesOnImplThread,
+                   impl_thread_weak_ptr_,
+                   &completion));
+    completion.Wait();
+  }
+}
+
+void ThreadProxy::CreateAndInitializeOutputSurface() {
   TRACE_EVENT0("cc", "ThreadProxy::DoCreateAndInitializeOutputSurface");
   DCHECK(IsMainThread());
 
   scoped_ptr<OutputSurface> output_surface =
       layer_tree_host()->CreateOutputSurface();
 
-  RendererCapabilities capabilities;
-  bool success = !!output_surface;
-  if (success) {
-    // Make a blocking call to InitializeOutputSurfaceOnImplThread. The results
-    // of that call are pushed into the success and capabilities local
-    // variables.
-    CompletionEvent completion;
-    DebugScopedSetMainThreadBlocked main_thread_blocked(this);
-
+  if (output_surface) {
     Proxy::ImplThreadTaskRunner()->PostTask(
         FROM_HERE,
         base::Bind(&ThreadProxy::InitializeOutputSurfaceOnImplThread,
                    impl_thread_weak_ptr_,
-                   &completion,
-                   base::Passed(&output_surface),
-                   &success,
-                   &capabilities));
-    completion.Wait();
+                   base::Passed(&output_surface)));
+    return;
   }
+
+  DidInitializeOutputSurface(false, RendererCapabilities());
+}
+
+void ThreadProxy::DidInitializeOutputSurface(
+    bool success,
+    const RendererCapabilities& capabilities) {
+  TRACE_EVENT0("cc", "ThreadProxy::DidInitializeOutputSurface");
+  DCHECK(IsMainThread());
   main().renderer_capabilities_main_thread_copy = capabilities;
   layer_tree_host()->OnCreateAndInitializeOutputSurfaceAttempted(success);
 
-  if (success) {
-    main().output_surface_creation_callback.Cancel();
-  } else if (!main().output_surface_creation_callback.IsCancelled()) {
+  if (!success) {
     Proxy::MainThreadTaskRunner()->PostTask(
-        FROM_HERE, main().output_surface_creation_callback.callback());
+        FROM_HERE,
+        base::Bind(&ThreadProxy::CreateAndInitializeOutputSurface,

[enne (OOO), 2014/05/16 22:37:29]

How is this not an infinite loop during failure?

CreateAndInitializeOutputSurface -> CreateOutputSurface returns NULL ->
DidInitializeOutputSurface(false, ...) ->
PostTask(...CreateAndInitializeOutputSurface...)

[danakj, 2014/05/16 22:45:29]

After 5 failures, LayerTreeHost will LOG(FATAL) in
OnCreateAndInitializeOutputSurfaceAttempted.

[enne (OOO), 2014/05/16 22:46:31]

And this will just keep posting tasks?

[danakj, 2014/05/16 22:48:40]

This calls OnCreateAndInitializeOutputSurfaceAttempted on line 243. The
LOG(FATAL) would crash so we'd stop. This should match our current behaviour
also, minus allowing the OutputSurface to be initailized mid-initialization by
CompositeAndReadback, at least this was my intent here.

+                   main_thread_weak_ptr_));
   }
 }
 
@@ -308,6 +327,9 @@ void ThreadProxy::CheckOutputSurfaceStatusOnImplThread() {
   DCHECK(IsImplThread());
   if (!impl().layer_tree_host_impl->IsContextLost())
     return;
+  Proxy::MainThreadTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&ThreadProxy::DidLoseOutputSurface, main_thread_weak_ptr_));
   impl().scheduler->DidLoseOutputSurface();
 }
 
@@ -1197,42 +1219,6 @@ void ThreadProxy::SetAnimationEvents(scoped_ptr<AnimationEventsVector> events) {
   layer_tree_host()->SetAnimationEvents(events.Pass());
 }
 
-void ThreadProxy::CreateAndInitializeOutputSurface() {
-  TRACE_EVENT0("cc", "ThreadProxy::CreateAndInitializeOutputSurface");
-  DCHECK(IsMainThread());
-
-  // Check that output surface has not been recreated by CompositeAndReadback
-  // after this task is posted but before it is run.
-  bool has_initialized_output_surface = true;
-  {
-    CompletionEvent completion;
-    Proxy::ImplThreadTaskRunner()->PostTask(
-        FROM_HERE,
-        base::Bind(&ThreadProxy::HasInitializedOutputSurfaceOnImplThread,
-                   impl_thread_weak_ptr_,
-                   &completion,
-                   &has_initialized_output_surface));
-    completion.Wait();
-  }
-  if (has_initialized_output_surface)
-    return;
-
-  layer_tree_host()->DidLoseOutputSurface();
-  main().output_surface_creation_callback.Reset(
-      base::Bind(&ThreadProxy::DoCreateAndInitializeOutputSurface,
-                 base::Unretained(this)));
-  main().output_surface_creation_callback.callback().Run();
-}
-
-void ThreadProxy::HasInitializedOutputSurfaceOnImplThread(
-    CompletionEvent* completion,
-    bool* has_initialized_output_surface) {
-  DCHECK(IsImplThread());
-  *has_initialized_output_surface =
-      impl().scheduler->HasInitializedOutputSurface();
-  completion->Signal();
-}
-
 void ThreadProxy::InitializeImplOnImplThread(CompletionEvent* completion) {
   TRACE_EVENT0("cc", "ThreadProxy::InitializeImplOnImplThread");
   DCHECK(IsImplThread());
@@ -1265,31 +1251,38 @@ void ThreadProxy::InitializeImplOnImplThread(CompletionEvent* completion) {
   completion->Signal();
 }
 
-void ThreadProxy::InitializeOutputSurfaceOnImplThread(
-    CompletionEvent* completion,
-    scoped_ptr<OutputSurface> output_surface,
-    bool* success,
-    RendererCapabilities* capabilities) {
-  TRACE_EVENT0("cc", "ThreadProxy::InitializeOutputSurfaceOnImplThread");
+void ThreadProxy::DeleteContentsTexturesOnImplThread(
+    CompletionEvent* completion) {
+  TRACE_EVENT0("cc", "ThreadProxy::DeleteContentsTexturesOnImplThread");
   DCHECK(IsImplThread());
   DCHECK(IsMainThreadBlocked());
-  DCHECK(success);
-  DCHECK(capabilities);
-
   layer_tree_host()->DeleteContentsTexturesOnImplThread(
       impl().layer_tree_host_impl->resource_provider());
+  completion->Signal();
+}
 
-  *success =
-      impl().layer_tree_host_impl->InitializeRenderer(output_surface.Pass());
+void ThreadProxy::InitializeOutputSurfaceOnImplThread(
+    scoped_ptr<OutputSurface> output_surface) {
+  TRACE_EVENT0("cc", "ThreadProxy::InitializeOutputSurfaceOnImplThread");
+  DCHECK(IsImplThread());
 
-  if (*success) {
-    *capabilities = impl()
-                        .layer_tree_host_impl->GetRendererCapabilities()
-                        .MainThreadCapabilities();
-    impl().scheduler->DidCreateAndInitializeOutputSurface();
+  LayerTreeHostImpl* host_impl = impl().layer_tree_host_impl.get();
+  bool success = host_impl->InitializeRenderer(output_surface.Pass());
+  RendererCapabilities capabilities;
+  if (success) {
+    capabilities =
+        host_impl->GetRendererCapabilities().MainThreadCapabilities();
   }
 
-  completion->Signal();
+  Proxy::MainThreadTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&ThreadProxy::DidInitializeOutputSurface,
+                 main_thread_weak_ptr_,
+                 success,
+                 capabilities));
+
+  if (success)
+    impl().scheduler->DidCreateAndInitializeOutputSurface();
 }
 
 void ThreadProxy::FinishGLOnImplThread(CompletionEvent* completion) {
@@ -1303,6 +1296,7 @@ void ThreadProxy::FinishGLOnImplThread(CompletionEvent* completion) {
 void ThreadProxy::LayerTreeHostClosedOnImplThread(CompletionEvent* completion) {
   TRACE_EVENT0("cc", "ThreadProxy::LayerTreeHostClosedOnImplThread");
   DCHECK(IsImplThread());
+  DCHECK(IsMainThreadBlocked());
   layer_tree_host()->DeleteContentsTexturesOnImplThread(
       impl().layer_tree_host_impl->resource_provider());
   impl().current_resource_update_controller.reset();