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// Copyright 2013 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.
#ifndef MOJO_SYSTEM_PROXY_MESSAGE_PIPE_ENDPOINT_H_
#define MOJO_SYSTEM_PROXY_MESSAGE_PIPE_ENDPOINT_H_
#include <stdint.h>
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "mojo/public/c/system/core.h"
#include "mojo/system/message_in_transit.h"
#include "mojo/system/message_in_transit_queue.h"
#include "mojo/system/message_pipe_endpoint.h"
#include "mojo/system/system_impl_export.h"
namespace mojo {
namespace system {
class Channel;
class LocalMessagePipeEndpoint;
class MessagePipe;
// A |ProxyMessagePipeEndpoint| connects an end of a |MessagePipe| to a
// |Channel|, over which it transmits and receives data (to/from another
// |ProxyMessagePipeEndpoint|). So a |MessagePipe| with one endpoint local and
// the other endpoint remote consists of a |LocalMessagePipeEndpoint| and a
// |ProxyMessagePipeEndpoint|, with only the local endpoint being accessible via
// a |MessagePipeDispatcher|.
//
// Like any |MessagePipeEndpoint|, a |ProxyMessagePipeEndpoint| is owned by a
// |MessagePipe|.
// - A |ProxyMessagePipeEndpoint| starts out *detached*, i.e., not associated
// to any |Channel|. When *attached*, it gets a reference to a |Channel| and
// is assigned a local ID. A |ProxyMessagePipeEndpoint| must be detached
// before destruction; this is done inside |Close()|.
// - When attached, a |ProxyMessagePipeEndpoint| starts out not running. When
// run, it gets a remote ID.
class MOJO_SYSTEM_IMPL_EXPORT ProxyMessagePipeEndpoint
: public MessagePipeEndpoint {
public:
ProxyMessagePipeEndpoint();
// Constructs a |ProxyMessagePipeEndpoint| that replaces the given
// |LocalMessagePipeEndpoint| (which this constructor will close), taking its
// message queue's contents. This is done when transferring a message pipe
// handle over a remote message pipe.
ProxyMessagePipeEndpoint(
LocalMessagePipeEndpoint* local_message_pipe_endpoint,
bool is_peer_open);
virtual ~ProxyMessagePipeEndpoint();
// |MessagePipeEndpoint| implementation:
virtual Type GetType() const OVERRIDE;
virtual bool OnPeerClose() OVERRIDE;
virtual void EnqueueMessage(scoped_ptr<MessageInTransit> message) OVERRIDE;
virtual void Attach(scoped_refptr<Channel> channel,
MessageInTransit::EndpointId local_id) OVERRIDE;
virtual bool Run(MessageInTransit::EndpointId remote_id) OVERRIDE;
virtual void OnRemove() OVERRIDE;
private:
void Detach();
#ifdef NDEBUG
void AssertConsistentState() const {}
#else
void AssertConsistentState() const;
#endif
bool is_attached() const {
return !!channel_.get();
}
bool is_running() const {
return remote_id_ != MessageInTransit::kInvalidEndpointId;
}
// This should only be set if we're attached.
scoped_refptr<Channel> channel_;
// |local_id_| should be set to something other than
// |MessageInTransit::kInvalidEndpointId| when we're attached.
MessageInTransit::EndpointId local_id_;
// |remote_id_| being set to anything other than
// |MessageInTransit::kInvalidEndpointId| indicates that we're "running",
// i.e., actively able to send messages. We should only ever be running if
// we're attached.
MessageInTransit::EndpointId remote_id_;
bool is_peer_open_;
// This queue is only used while we're detached, to store messages while we're
// not ready to send them yet.
MessageInTransitQueue paused_message_queue_;
DISALLOW_COPY_AND_ASSIGN(ProxyMessagePipeEndpoint);
};
} // namespace system
} // namespace mojo
#endif // MOJO_SYSTEM_PROXY_MESSAGE_PIPE_ENDPOINT_H_
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