Mus: Avoid deadlock during teardown

services/ui/gpu/gpu_service_internal.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_internal.h"
 
 #include "base/bind.h"
 #include "base/memory/shared_memory.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
@@ skipping 23 matching lines @@
 #include "ui/gl/gpu_switching_manager.h"
 #include "ui/gl/init/gl_factory.h"
 #include "url/gurl.h"
 
 namespace ui {
 
 GpuServiceInternal::GpuServiceInternal(
     const gpu::GPUInfo& gpu_info,
     std::unique_ptr<gpu::GpuWatchdogThread> watchdog_thread,
     gpu::GpuMemoryBufferFactory* gpu_memory_buffer_factory,
-    scoped_refptr<base::SingleThreadTaskRunner> io_runner)
+    scoped_refptr<base::SingleThreadTaskRunner> io_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> compositor_runner)
     : io_runner_(std::move(io_runner)),
+      compositor_runner_(std::move(compositor_runner)),
       shutdown_event_(base::WaitableEvent::ResetPolicy::MANUAL,
                       base::WaitableEvent::InitialState::NOT_SIGNALED),
       watchdog_thread_(std::move(watchdog_thread)),
       gpu_memory_buffer_factory_(gpu_memory_buffer_factory),
-      gpu_info_(gpu_info),
-      compositor_thread_("DisplayCompositorThread") {
-  compositor_thread_.Start();
-}
+      gpu_info_(gpu_info) {}
 
 GpuServiceInternal::~GpuServiceInternal() {
   bindings_.CloseAllBindings();
   media_gpu_channel_manager_.reset();
   gpu_channel_manager_.reset();
   owned_sync_point_manager_.reset();
 
   // Signal this event before destroying the child process.  That way all
   // background threads can cleanup.
   // For example, in the renderer the RenderThread instances will be able to
@@ skipping 31 matching lines @@
     cc::mojom::DisplayCompositorRequest request,
     cc::mojom::DisplayCompositorClientPtr client) {
   DCHECK(CalledOnValidThread());
   DCHECK(!gpu_command_service_);
   gpu_command_service_ = new gpu::GpuInProcessThreadService(
       base::ThreadTaskRunnerHandle::Get(), owned_sync_point_manager_.get(),
       gpu_channel_manager_->mailbox_manager(),
       gpu_channel_manager_->share_group());
   mojom::GpuServiceInternalPtr gpu_service_ptr;
   Add(mojo::GetProxy(&gpu_service_ptr));
-  compositor_thread_.task_runner()->PostTask(
+  compositor_runner_->PostTask(
       FROM_HERE,
       base::Bind(&GpuServiceInternal::CreateDisplayCompositorOnCompositorThread,
                  base::Unretained(this),
                  base::Passed(gpu_service_ptr.PassInterface()),
                  base::Passed(&request), base::Passed(client.PassInterface())));
 }
 
 void GpuServiceInternal::CreateDisplayCompositorOnCompositorThread(
     mojom::GpuServiceInternalPtrInfo gpu_service_info,
     cc::mojom::DisplayCompositorRequest request,
     cc::mojom::DisplayCompositorClientPtrInfo client_info) {
-  DCHECK(compositor_thread_.task_runner()->BelongsToCurrentThread());
+  DCHECK(compositor_runner_->BelongsToCurrentThread());
   mojom::GpuServiceInternalPtr gpu_service_ptr;
   gpu_service_ptr.Bind(std::move(gpu_service_info));
 
   cc::mojom::DisplayCompositorClientPtr client_ptr;
   client_ptr.Bind(std::move(client_info));
 
   std::unique_ptr<MusGpuMemoryBufferManager> gpu_memory_buffer_manager =
       base::MakeUnique<MusGpuMemoryBufferManager>(std::move(gpu_service_ptr),
                                                   1 /* client_id */);
   // |gpu_memory_buffer_factory_| is null in tests.
   gpu::ImageFactory* image_factory =
       gpu_memory_buffer_factory_ ? gpu_memory_buffer_factory_->AsImageFactory()
                                  : nullptr;
-  mojo::MakeStrongBinding(
-      base::MakeUnique<DisplayCompositor>(gpu_command_service_,
-                                          std::move(gpu_memory_buffer_manager),
-                                          image_factory, std::move(client_ptr)),
-      std::move(request));
+  display_compositor_ = base::MakeUnique<DisplayCompositor>(
+      gpu_command_service_, std::move(gpu_memory_buffer_manager), image_factory,
+      std::move(request), std::move(client_ptr));
 }
+
+void GpuServiceInternal::DestroyDisplayCompositor() {
+  if (compositor_runner_->BelongsToCurrentThread()) {
+    DestroyDisplayCompositorOnCompositorThread();
+    return;
+  }
+  compositor_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(
+          &GpuServiceInternal::DestroyDisplayCompositorOnCompositorThread,
+          base::Unretained(this)));
+}
+
+void GpuServiceInternal::DestroyDisplayCompositorOnCompositorThread() {
+  display_compositor_.reset();
+}
+
 void GpuServiceInternal::DidCreateOffscreenContext(const GURL& active_url) {
   NOTIMPLEMENTED();
 }
 
 void GpuServiceInternal::DidDestroyChannel(int client_id) {
   media_gpu_channel_manager_->RemoveChannel(client_id);
   NOTIMPLEMENTED();
 }
 
 void GpuServiceInternal::DidDestroyOffscreenContext(const GURL& active_url) {
@@ skipping 71 matching lines @@
   mojo::ScopedMessagePipeHandle channel_handle;
   IPC::ChannelHandle handle = gpu_channel_manager_->EstablishChannel(
       client_id, client_tracing_id, preempts, allow_view_command_buffers,
       allow_real_time_streams);
   channel_handle.reset(handle.mojo_handle);
   media_gpu_channel_manager_->AddChannel(client_id);
   callback.Run(std::move(channel_handle));
 }
 
 }  // namespace ui