blob: 7f9c720f8d4e11c9360aaa4aa72a5671dcdb8128 [file] [log] [blame]
// Copyright 2014 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 <map>
#include <set>
#include "base/bind.h"
#include "base/callback_forward.h"
#include "base/synchronization/lock.h"
#include "base/task_runner.h"
#include "base/threading/thread_checker.h"
#include "content/common/content_export.h"
#include "ipc/message_filter.h"
namespace content {
// This class can be used to intercept routed messages and
// deliver them to a compositor task runner than they would otherwise
// be sent. Messages are filtered based on type. To route these messages,
// add a Handler to the filter.
// The user of this class implements CompositorForwardingMessageFilter::Handler,
// which will receive the intercepted messages, on the compositor thread.
// The caller must ensure that each handler in |multi_handlers_| outlives the
// lifetime of the filter.
// User can add multiple handlers for specific routing id. When messages have
// arrived, all handlers in |multi_handlers_| for routing id will be executed.
// Note: When we want to add new message, add a new switch case in
// OnMessageReceived() then add a new Handler for it.
class CONTENT_EXPORT CompositorForwardingMessageFilter
: public IPC::MessageFilter {
// The handler is invoked on the compositor thread with messages that were
// intercepted by this filter.
typedef base::Callback<void(const IPC::Message&)> Handler;
// This filter will intercept messages defined in OnMessageReceived() and run
// them by ProcessMessageOnCompositorThread on compositor thread.
CompositorForwardingMessageFilter(base::TaskRunner* compositor_task_runner);
void AddHandlerOnCompositorThread(int routing_id, const Handler& handler);
void RemoveHandlerOnCompositorThread(int routing_id, const Handler& handler);
// MessageFilter methods:
virtual bool OnMessageReceived(const IPC::Message& message) override;
virtual ~CompositorForwardingMessageFilter();
void ProcessMessageOnCompositorThread(const IPC::Message& message);
// The handler only gets run on the compositor thread.
scoped_refptr<base::TaskRunner> compositor_task_runner_;
// This is used to check some functions that are only running on compositor
// thread.
base::ThreadChecker compositor_thread_checker_;
// Maps the routing_id for which messages should be filtered and handlers
// which will be routed.
std::multimap<int, Handler> multi_handlers_;
} // namespace content