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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_MESSAGE_PIPE_ENDPOINT_H_
#define MOJO_SYSTEM_MESSAGE_PIPE_ENDPOINT_H_
#include <stdint.h>
#include <vector>
#include "base/basictypes.h"
#include "base/memory/ref_counted.h"
#include "mojo/public/system/core.h"
#include "mojo/public/system/system_export.h"
#include "mojo/system/message_in_transit.h"
namespace mojo {
namespace system {
class Channel;
class Dispatcher;
class Waiter;
// This is an interface to one of the ends of a message pipe, and is used by
// |MessagePipe|. Its most important role is to provide a sink for messages
// (i.e., a place where messages can be sent). It has a secondary role: When the
// endpoint is local (i.e., in the current process), there'll be a dispatcher
// corresponding to the endpoint. In that case, the implementation of
// |MessagePipeEndpoint| also implements the functionality required by the
// dispatcher, e.g., to read messages and to wait. Implementations of this class
// are not thread-safe; instances are protected by |MesssagePipe|'s lock.
class MOJO_SYSTEM_EXPORT MessagePipeEndpoint {
public:
virtual ~MessagePipeEndpoint() {}
// All implementations must implement these.
virtual void Close() = 0;
// Returns false if the endpoint should be closed and destroyed, else true.
virtual bool OnPeerClose() = 0;
// Checks if |EnqueueMessage()| will be able to enqueue the given message
// (with the given set of dispatchers). |dispatchers| should be non-null only
// if it's nonempty. Returns |MOJO_RESULT_OK| if it will and an appropriate
// error code if it won't.
virtual MojoResult CanEnqueueMessage(
const MessageInTransit* message,
const std::vector<Dispatcher*>* dispatchers) = 0;
// Takes ownership of |message| and the contents of |dispatchers| (leaving
// it empty). This should only be called after |CanEnqueueMessage()| has
// indicated success. (Unlike |CanEnqueueMessage()|, |dispatchers| may be
// non-null but empty.)
virtual void EnqueueMessage(
MessageInTransit* message,
std::vector<scoped_refptr<Dispatcher> >* dispatchers) = 0;
// Implementations must override these if they represent a local endpoint,
// i.e., one for which there's a |MessagePipeDispatcher| (and thus a handle).
// An implementation for a proxy endpoint (for which there's no dispatcher)
// needs not override these methods, since they should never be called.
//
// These methods implement the methods of the same name in |MessagePipe|,
// though |MessagePipe|'s implementation may have to do a little more if the
// operation involves both endpoints.
virtual void CancelAllWaiters();
virtual MojoResult ReadMessage(
void* bytes, uint32_t* num_bytes,
std::vector<scoped_refptr<Dispatcher> >* dispatchers,
uint32_t* num_dispatchers,
MojoReadMessageFlags flags);
virtual MojoResult AddWaiter(Waiter* waiter,
MojoWaitFlags flags,
MojoResult wake_result);
virtual void RemoveWaiter(Waiter* waiter);
// Implementations must override these if they represent a proxy endpoint. An
// implementation for a local endpoint needs not override these methods, since
// they should never be called.
virtual void Attach(scoped_refptr<Channel> channel,
MessageInTransit::EndpointId local_id);
// Returns false if the endpoint should be closed and destroyed, else true.
virtual bool Run(MessageInTransit::EndpointId remote_id);
protected:
MessagePipeEndpoint() {}
private:
DISALLOW_COPY_AND_ASSIGN(MessagePipeEndpoint);
};
} // namespace system
} // namespace mojo
#endif // MOJO_SYSTEM_MESSAGE_PIPE_ENDPOINT_H_