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// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef IPC_IPC_SYNC_MESSAGE_FILTER_H_
#define IPC_IPC_SYNC_MESSAGE_FILTER_H_
#include <set>
#include <vector>
#include "base/component_export.h"
#include "base/memory/raw_ptr.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "ipc/ipc_sender.h"
#include "ipc/ipc_sync_message.h"
#include "ipc/message_filter.h"
#include "mojo/public/cpp/bindings/generic_pending_associated_receiver.h"
#include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h"
namespace base {
class SingleThreadTaskRunner;
class WaitableEvent;
}
namespace IPC {
class SyncChannel;
// This MessageFilter allows sending synchronous IPC messages from a thread
// other than the listener thread associated with the SyncChannel. It does not
// support fancy features that SyncChannel does, such as handling recursion or
// receiving messages while waiting for a response. Note that this object can
// be used to send simultaneous synchronous messages from different threads.
class COMPONENT_EXPORT(IPC) SyncMessageFilter : public MessageFilter,
public Sender {
public:
SyncMessageFilter(const SyncMessageFilter&) = delete;
SyncMessageFilter& operator=(const SyncMessageFilter&) = delete;
// Sender implementation.
bool Send(Message* message) override;
// MessageFilter implementation.
void OnFilterAdded(Channel* channel) override;
void OnChannelError() override;
void OnChannelClosing() override;
bool OnMessageReceived(const Message& message) override;
// Binds an associated interface proxy to an interface in the browser process.
// Interfaces acquired through this method are associated with the IPC Channel
// and as such retain FIFO with legacy IPC messages.
//
// NOTE: This must ONLY be called on the Channel's thread, after
// OnFilterAdded.
void GetRemoteAssociatedInterface(
mojo::GenericPendingAssociatedReceiver receiver);
template <typename Interface>
void GetRemoteAssociatedInterface(
mojo::PendingAssociatedRemote<Interface>* proxy) {
GetRemoteAssociatedInterface(proxy->InitWithNewEndpointAndPassReceiver());
}
protected:
explicit SyncMessageFilter(base::WaitableEvent* shutdown_event);
~SyncMessageFilter() override;
private:
friend class SyncChannel;
void SendOnIOThread(Message* message);
// Signal all the pending sends as done, used in an error condition.
void SignalAllEvents();
// The channel to which this filter was added.
raw_ptr<Channel> channel_;
// The process's main thread.
scoped_refptr<base::SingleThreadTaskRunner> listener_task_runner_;
// The message loop where the Channel lives.
scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
typedef std::set<PendingSyncMsg*> PendingSyncMessages;
PendingSyncMessages pending_sync_messages_;
// Messages waiting to be delivered after IO initialization.
std::vector<std::unique_ptr<Message>> pending_messages_;
// Locks data members above.
base::Lock lock_;
const raw_ptr<base::WaitableEvent> shutdown_event_;
};
} // namespace IPC
#endif // IPC_IPC_SYNC_MESSAGE_FILTER_H_