Sample code: IPC Transport object for GPU

content/gpu/chrome_gpu_memory_buffer_service_ipc_transport.cc

+// Copyright 2015 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/gpu/chrome_gpu_memory_buffer_service_ipc_transport.h"
+
+#include "content/common/gpu/gpu_messages.h"
+#include "ipc/ipc_sender.h"
+
+namespace content {
+
+namespace {
+
+class GpuMemoryBufferServiceMessageFilter : public IPC::MessageFilter {
+ public:
+  explicit GpuMemoryBufferServiceMessageFilter(
+      const base::WeakPtr<ChromeGpuMemoryBufferServiceIPCTransport>& transport)
+      : transport_(transport) {}
+
+ private:
+  ~GpuMemoryBufferServiceMessageFilter() override {}
+
+  // Overridden from IPC::MessageFilter:
+  void OnFilterAdded(IPC::Sender* sender) override {
+    if (transport_) {
+      DCHECK(!transport_->sender_);
+      transport_->sender_ = sender;
+    }
+  }
+
+  void OnFilterRemoved() override {
+    if (transport_) {
+      DCHECK(transport_->sender_);
+      transport_->sender_ = nullptr;
+      transport_->CloseConnection();
+    }
+  }
+
+  bool OnMessageReceived(const IPC::Message& message) override {
+    if (transport_)
+      return transport_->OnMessageReceived(message);
+    return false;
+  }
+
+  base::WeakPtr<ChromeGpuMemoryBufferServiceIPCTransport> transport_;
+
+  DISALLOW_COPY_AND_ASSIGN(GpuMemoryBufferServiceMessageFilter);
+};
+
+}  // namespace
+
+// static
+scoped_ptr<GpuMemoryBufferServiceIPCTransport>
+ChromeGpuMemoryBufferServiceIPCTransport::Create() {
+  return make_scoped_ptr<GpuMemoryBufferServiceIPCTransport>(
+      new ChromeGpuMemoryBufferServiceIPCTransport());
+}
+
+ChromeGpuMemoryBufferServiceIPCTransport::
+    ~ChromeGpuMemoryBufferServiceIPCTransport() {}
+
+ChromeGpuMemoryBufferServiceIPCTransport::
+    ChromeGpuMemoryBufferServiceIPCTransport()
+    : client_(nullptr), sender_(nullptr), factory_(this) {
+  message_filter_ =
+      new GpuMemoryBufferServiceMessageFilter(factory_.GetWeakPtr());
+}
+
+void ChromeGpuMemoryBufferServiceIPCTransport::CloseConnection() {
+  if (client_)
+    client_->OnConnectionClosed();
+}
+
+bool ChromeGpuMemoryBufferServiceIPCTransport::GpuMemoryBufferCreated(
+    const gfx::GpuMemoryBufferHandle& handle) {
+  DCHECK(sender_);
+  return sender_->Send(new GpuHostMsg_GpuMemoryBufferCreated(handle));
+}
+
+void ChromeGpuMemoryBufferServiceIPCTransport::SetClient(
+    GpuMemoryBufferServiceIPCTransport::Client* client) {
+  client_ = client;
+}
+
+bool ChromeGpuMemoryBufferServiceIPCTransport::OnMessageReceived(
+    const IPC::Message& message) {
+  DCHECK(sender_);
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(ChromeGpuMemoryBufferServiceIPCTransport, message)
+    IPC_MESSAGE_HANDLER(GpuMsg_CreateGpuMemoryBuffer, OnCreateGpuMemoryBuffer)
+    IPC_MESSAGE_HANDLER(GpuMsg_CreateGpuMemoryBufferFromHandle,
+                        OnCreateGpuMemoryBufferFromHandle)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void ChromeGpuMemoryBufferServiceIPCTransport::OnCreateGpuMemoryBuffer(
+    const CreateGpuMemoryBufferParams& params) {
+  if (client_)
+    client_->OnCreateGpuMemoryBuffer(params);
+}
+
+void ChromeGpuMemoryBufferServiceIPCTransport::
+    OnCreateGpuMemoryBufferFromHandle(
+        const CreateGpuMemoryBufferFromHandleParams& params) {
+  if (client_)
+    client_->OnCreateGpuMemoryBufferFromHandle(params);
+}
+
+}  // namespace content