Refactor ChildProcess and related classes to create a framework outside of br...

base/mp/mp_child_thread.cc

+// Copyright (c) 2010 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 "base/mp/mp_child_thread.h"
+
+#include "base/string_util.h"
+#include "base/command_line.h"
+#include "base/mp/mp_child_process.h"
+#include "base/mp/mp_messages.h"
+#include "ipc/ipc_logging.h"
+#include "ipc/ipc_message.h"
+#include "ipc/ipc_sync_message_filter.h"
+#include "ipc/ipc_switches.h"
+
+namespace base {
+
+MpChildThread::MpChildThread() {
+  channel_name_ = CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+      switches::kProcessChannelID);
+  Init();
+}
+
+MpChildThread::MpChildThread(const std::string& channel_name)
+    : channel_name_(channel_name) {
+  Init();
+}
+
+void MpChildThread::Init() {
+  check_with_parent_before_shutdown_ = false;
+  on_channel_error_called_ = false;
+  message_loop_ = MessageLoop::current();
+
+  channel_.reset(new IPC::SyncChannel(channel_name_,
+      IPC::Channel::MODE_CLIENT, this, NULL,
+      MpChildProcess::current()->io_message_loop(), true,
+      MpChildProcess::current()->GetShutDownEvent()));
+#ifdef IPC_MESSAGE_LOG_ENABLED
+  IPC::Logging::current()->SetIPCSender(this);
+#endif
+
+  sync_message_filter_ =
+      new IPC::SyncMessageFilter(MpChildProcess::current()->GetShutDownEvent());
+  channel_->AddFilter(sync_message_filter_.get());
+}
+
+MpChildThread::~MpChildThread() {
+#ifdef IPC_MESSAGE_LOG_ENABLED
+  IPC::Logging::current()->SetIPCSender(NULL);
+#endif
+
+  channel_->RemoveFilter(sync_message_filter_.get());
+
+  // The ChannelProxy object caches a pointer to the IPC thread, so need to
+  // reset it as it's not guaranteed to outlive this object.
+  // NOTE: this also has the side-effect of not closing the main IPC channel to
+  // the browser process.  This is needed because this is the signal that the
+  // browser uses to know that this process has died, so we need it to be alive
+  // until this process is shut down, and the OS closes the handle
+  // automatically.  We used to watch the object handle on Windows to do this,
+  // but it wasn't possible to do so on POSIX.
+  channel_->ClearIPCMessageLoop();
+}
+
+void MpChildThread::OnChannelError() {
+  set_on_channel_error_called(true);
+  MessageLoop::current()->Quit();
+}
+
+bool MpChildThread::Send(IPC::Message* msg) {
+  if (!channel_.get()) {
+    delete msg;
+    return false;
+  }
+
+  return channel_->Send(msg);
+}
+
+void MpChildThread::AddRoute(int32 routing_id, IPC::Channel::Listener* listener) {
+  DCHECK(MessageLoop::current() == message_loop());
+
+  router_.AddRoute(routing_id, listener);
+}
+
+void MpChildThread::RemoveRoute(int32 routing_id) {
+  DCHECK(MessageLoop::current() == message_loop());
+
+  router_.RemoveRoute(routing_id);
+}
+
+IPC::Channel::Listener* MpChildThread::ResolveRoute(int32 routing_id) {
+  DCHECK(MessageLoop::current() == message_loop());
+
+  return router_.ResolveRoute(routing_id);
+}
+
+void MpChildThread::OnMessageReceived(const IPC::Message& msg) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(MpChildThread, msg)
+    IPC_MESSAGE_HANDLER(MultiProcessMsg_AskBeforeShutdown, OnAskBeforeShutdown)
+    IPC_MESSAGE_HANDLER(MultiProcessMsg_Shutdown, OnShutdown)
+#if defined(IPC_MESSAGE_LOG_ENABLED)
+    IPC_MESSAGE_HANDLER(MultiProcessMsg_SetIPCLoggingEnabled,
+                        OnSetIPCLoggingEnabled)
+#endif
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+
+  if (handled)
+    return;
+
+  if (msg.routing_id() == MSG_ROUTING_CONTROL) {
+    OnControlMessageReceived(msg);
+  } else {
+    router_.OnMessageReceived(msg);
+  }
+}
+
+void MpChildThread::OnAskBeforeShutdown() {
+  check_with_parent_before_shutdown_ = true;
+}
+
+void MpChildThread::OnShutdown() {
+  MessageLoop::current()->Quit();
+}
+
+#if defined(IPC_MESSAGE_LOG_ENABLED)
+void MpChildThread::OnSetIPCLoggingEnabled(bool enable) {
+  if (enable)
+    IPC::Logging::current()->Enable();
+  else
+    IPC::Logging::current()->Disable();
+}
+#endif  //  IPC_MESSAGE_LOG_ENABLED
+
+MpChildThread* MpChildThread::current() {
+  return MpChildProcess::current()->main_thread();
+}
+
+void MpChildThread::OnProcessFinalRelease() {
+  if (on_channel_error_called_ || !check_with_parent_before_shutdown_) {
+    MessageLoop::current()->Quit();
+    return;
+  }
+
+  // The child process shutdown sequence is a request response based mechanism,
+  // where we send out an initial feeler request to the child process host
+  // instance in the browser to verify if it's ok to shutdown the child process.
+  // The browser then sends back a response if it's ok to shutdown.
+  Send(new MultiProcessHostMsg_ShutdownRequest);
+}
+
+}  // namespace base