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

base/mp/mp_child_process.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_process.h"
+
+#include "base/message_loop.h"
+#include "base/mp/mp_child_thread.h"
+
+namespace base {
+
+MpChildProcess* MpChildProcess::child_process_;
+
+MpChildProcess::MpChildProcess()
+    : ref_count_(0),
+      shutdown_event_(true, false) {
+  DCHECK(!child_process_);
+  child_process_ = this;
+}
+
+MpChildProcess::~MpChildProcess() {
+  DCHECK(child_process_ == this);
+
+  // 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
+  // notice shutdown before the render process begins waiting for them to exit.
+  shutdown_event_.Signal();
+
+  // Kill the main thread object before nulling child_process_, since
+  // destruction code might depend on it.
+  main_thread_.reset();
+
+  child_process_ = NULL;
+}
+
+void MpChildProcess::AddRefProcess() {
+  DCHECK(!main_thread_.get() ||  // null in unittests.
+         MessageLoop::current() == main_thread_->message_loop());
+  ref_count_++;
+}
+
+void MpChildProcess::ReleaseProcess() {
+  DCHECK(!main_thread_.get() ||  // null in unittests.
+         MessageLoop::current() == main_thread_->message_loop());
+  DCHECK(ref_count_);
+  DCHECK(child_process_);
+  if (--ref_count_)
+    return;
+
+  if (main_thread_.get())  // null in unittests.
+    main_thread_->OnProcessFinalRelease();
+}
+
+base::WaitableEvent* MpChildProcess::GetShutDownEvent() {
+  DCHECK(child_process_);
+  return &child_process_->shutdown_event_;
+}
+
+}  // namespace base