mus-gpu: Talk to the GpuHost from the IO thread.

services/ui/gpu/gpu_service.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/gpu/gpu_service.h"
 
 #include "base/bind.h"
 #include "base/debug/crash_logging.h"
 #include "base/memory/shared_memory.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 57 matching lines @@
   // notice shutdown before the render process begins waiting for them to exit.
   shutdown_event_.Signal();
 }
 
 void GpuService::InitializeWithHost(mojom::GpuHostPtr gpu_host,
                                     const gpu::GpuPreferences& preferences,
                                     gpu::GpuProcessActivityFlags activity_flags,
                                     gpu::SyncPointManager* sync_point_manager,
                                     base::WaitableEvent* shutdown_event) {
   DCHECK(CalledOnValidThread());
-  DCHECK(!gpu_host_);
-  gpu_host_ = std::move(gpu_host);
   gpu_preferences_ = preferences;
   gpu_info_.video_decode_accelerator_capabilities =
       media::GpuVideoDecodeAccelerator::GetCapabilities(gpu_preferences_);
   gpu_info_.video_encode_accelerator_supported_profiles =
       media::GpuVideoEncodeAccelerator::GetSupportedProfiles(gpu_preferences_);
   gpu_info_.jpeg_decode_accelerator_supported =
       media::GpuJpegDecodeAcceleratorFactoryProvider::
           IsAcceleratedJpegDecodeSupported();
-  gpu_host_->DidInitialize(gpu_info_);
+  gpu_host->DidInitialize(gpu_info_);
+
+  task_tracker_.PostTask(
+      io_runner_.get(), FROM_HERE,
+      base::Bind(&GpuService::BindGpuHostOnIO, base::Unretained(this),
+                 base::Passed(gpu_host.PassInterface())));
 
   sync_point_manager_ = sync_point_manager;
   if (!sync_point_manager_) {
     owned_sync_point_manager_ = base::MakeUnique<gpu::SyncPointManager>();
     sync_point_manager_ = owned_sync_point_manager_.get();
   }
 
   // Defer creation of the render thread. This is to prevent it from handling
   // IPC messages before the sandbox has been enabled and all other necessary
   // initialization has succeeded.
   gpu_channel_manager_.reset(new gpu::GpuChannelManager(
       gpu_preferences_, this, watchdog_thread_.get(),
       base::ThreadTaskRunnerHandle::Get().get(), io_runner_.get(),
       shutdown_event ? shutdown_event : &shutdown_event_, sync_point_manager_,
       gpu_memory_buffer_factory_, gpu_feature_info_,
       std::move(activity_flags)));
 
   media_gpu_channel_manager_.reset(
       new media::MediaGpuChannelManager(gpu_channel_manager_.get()));
 }
 
 void GpuService::Bind(mojom::GpuServiceRequest request) {
   bindings_.AddBinding(this, std::move(request));
 }
 
+void GpuService::BindGpuHostOnIO(mojom::GpuHostPtrInfo ptr_info) {
+  DCHECK(io_runner_->RunsTasksOnCurrentThread());
+  mojom::GpuHostPtr gpu_host;
+  gpu_host.Bind(std::move(ptr_info));
+  gpu_host_ = mojom::ThreadSafeGpuHostPtr::Create(std::move(gpu_host));

[Ken Rockot(use gerrit already), 2017/03/21 22:40:35]

The ThreadSafeInterfacePtr itself is thread-safe, but |gpu_host_| storage is
not. This would need to be guarded by a lock now, wouldn't it?

You can avoid this by instead calling, in the constructor:

gpu_host_ = mojom::ThreadSafeGpuHostPtr::Create(gpu_host.PassInterface(),
io_runner_);

I don't think you'd need a CancelableTaskTracker then either?

[sadrul, 2017/03/21 22:43:10]

Ooh, so ThreadSafe* can be take a task-runner of a different thread? That's
awesome :) Yep, that simplifies this a lot. I will make that change. Thanks!

[sadrul, 2017/03/21 23:14:17]

Done.

+}
+
 void GpuService::CreateGpuMemoryBuffer(
     gfx::GpuMemoryBufferId id,
     const gfx::Size& size,
     gfx::BufferFormat format,
     gfx::BufferUsage usage,
     int client_id,
     gpu::SurfaceHandle surface_handle,
     const CreateGpuMemoryBufferCallback& callback) {
   DCHECK(CalledOnValidThread());
   callback.Run(gpu_memory_buffer_factory_->CreateGpuMemoryBuffer(
@@ skipping 12 matching lines @@
     const GetVideoMemoryUsageStatsCallback& callback) {
   gpu::VideoMemoryUsageStats video_memory_usage_stats;
   if (gpu_channel_manager_) {
     gpu_channel_manager_->gpu_memory_manager()->GetVideoMemoryUsageStats(
         &video_memory_usage_stats);
   }
   callback.Run(video_memory_usage_stats);
 }
 
 void GpuService::DidCreateOffscreenContext(const GURL& active_url) {
-  gpu_host_->DidCreateOffscreenContext(active_url);
+  (*gpu_host_)->DidCreateOffscreenContext(active_url);
 }
 
 void GpuService::DidDestroyChannel(int client_id) {
   media_gpu_channel_manager_->RemoveChannel(client_id);
-  gpu_host_->DidDestroyChannel(client_id);
+  (*gpu_host_)->DidDestroyChannel(client_id);
 }
 
 void GpuService::DidDestroyOffscreenContext(const GURL& active_url) {
-  gpu_host_->DidDestroyOffscreenContext(active_url);
+  (*gpu_host_)->DidDestroyOffscreenContext(active_url);
 }
 
 void GpuService::DidLoseContext(bool offscreen,
                                 gpu::error::ContextLostReason reason,
                                 const GURL& active_url) {
-  gpu_host_->DidLoseContext(offscreen, reason, active_url);
+  (*gpu_host_)->DidLoseContext(offscreen, reason, active_url);
 }
 
 void GpuService::StoreShaderToDisk(int client_id,
                                    const std::string& key,
                                    const std::string& shader) {
-  gpu_host_->StoreShaderToDisk(client_id, key, shader);
+  (*gpu_host_)->StoreShaderToDisk(client_id, key, shader);
 }
 
 #if defined(OS_WIN)
 void GpuService::SendAcceleratedSurfaceCreatedChildWindow(
     gpu::SurfaceHandle parent_window,
     gpu::SurfaceHandle child_window) {
-  gpu_host_->SetChildSurface(parent_window, child_window);
+  (*gpu_host_)->SetChildSurface(parent_window, child_window);
 }
 #endif
 
 void GpuService::SetActiveURL(const GURL& url) {
   constexpr char kActiveURL[] = "url-chunk";
   base::debug::SetCrashKeyValue(kActiveURL, url.possibly_invalid_spec());
 }
 
 void GpuService::EstablishGpuChannel(
     int32_t client_id,
@@ skipping 81 matching lines @@
   NOTREACHED() << "Java exception not supported on this platform.";
 #endif
 }
 
 void GpuService::Stop(const StopCallback& callback) {
   base::MessageLoop::current()->QuitWhenIdle();
   callback.Run();
 }
 
 }  // namespace ui