Implement GpuArcVideoService for arc video accelerator

content/common/gpu/media/gpu_arc_video_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 "content/common/gpu/media/gpu_arc_video_service.h"
+
+#include "base/logging.h"
+#include "content/common/gpu/gpu_messages.h"
+#include "ipc/ipc_listener.h"
+#include "ipc/ipc_message_macros.h"
+#include "ipc/ipc_sync_channel.h"
+
+namespace content {
+
+// TODO(kcwu) implement ArcVideoAccelerator::Client.
+class GpuArcVideoService::AcceleratorStub : public IPC::Listener,
+                                            public IPC::Sender {
+ public:
+  // |owner| outlives AcceleratorStub.
+  explicit AcceleratorStub(GpuArcVideoService* owner) : owner_(owner) {}
+
+  ~AcceleratorStub() override {
+    DCHECK(thread_checker_.CalledOnValidThread());
+    channel_->Close();
+  }
+
+  IPC::ChannelHandle CreateChannel(
+      base::WaitableEvent* shutdown_event,
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner) {
+    IPC::ChannelHandle handle =
+        IPC::Channel::GenerateVerifiedChannelID("arc-video");
+    channel_ = IPC::SyncChannel::Create(handle, IPC::Channel::MODE_SERVER, this,
+                                        io_task_runner, false, shutdown_event);
+    base::ScopedFD client_fd = channel_->TakeClientFileDescriptor();
+    DCHECK(client_fd.is_valid());
+    handle.socket = base::FileDescriptor(std::move(client_fd));
+    return handle;
+  }
+
+  // IPC::Sender implementation:
+  bool Send(IPC::Message* msg) override {
+    DCHECK(msg);
+    return channel_->Send(msg);
+  }
+
+  // IPC::Listener implementation:
+  void OnChannelError() override {
+    DCHECK(thread_checker_.CalledOnValidThread());
+    // RemoveClient will delete |this|.

[mdempsky, 2016/01/09 01:07:05]

Why not just do "delete this;"?  RemoveClient doesn't seem to be called
otherwise, and then you can get rid of RemoveClient and accelerator_stubs_.

[kcwu, 2016/01/09 03:22:04]

We have to keep accelerator_stubs_ because
GpuChannelManager::OnShutdownArcVideoService() will delete GpuArcVideoService
and implicitly delete accelerator_stubs_.

+    owner_->RemoveClient(this);
+  }
+
+  // IPC::Listener implementation:
+  bool OnMessageReceived(const IPC::Message& msg) override {
+    DCHECK(thread_checker_.CalledOnValidThread());
+
+    // TODO(kcwu) Add handlers here.
+    return false;
+  }
+
+ private:
+  base::ThreadChecker thread_checker_;
+  GpuArcVideoService* const owner_;
+  scoped_ptr<IPC::SyncChannel> channel_;
+};
+
+GpuArcVideoService::GpuArcVideoService(
+    base::WaitableEvent* shutdown_event,
+    const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner)
+    : shutdown_event_(shutdown_event), io_task_runner_(io_task_runner) {}
+
+GpuArcVideoService::~GpuArcVideoService() {}
+
+void GpuArcVideoService::CreateChannel(const CreateChannelCallback& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  scoped_ptr<AcceleratorStub> stub(new AcceleratorStub(this));
+
+  IPC::ChannelHandle handle =
+      stub->CreateChannel(shutdown_event_, io_task_runner_);
+  accelerator_stubs_[stub.get()] = std::move(stub);
+
+  callback.Run(handle);
+}
+
+void GpuArcVideoService::RemoveClient(AcceleratorStub* stub) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  accelerator_stubs_.erase(stub);
+}
+
+}  // namespace content