1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef MOJO_SYSTEM_MESSAGE_PIPE_ENDPOINT_H_
6 #define MOJO_SYSTEM_MESSAGE_PIPE_ENDPOINT_H_
12 #include "base/macros.h"
13 #include "base/memory/ref_counted.h"
14 #include "base/memory/scoped_ptr.h"
15 #include "mojo/public/c/system/message_pipe.h"
16 #include "mojo/public/c/system/types.h"
17 #include "mojo/system/dispatcher.h"
18 #include "mojo/system/memory.h"
19 #include "mojo/system/message_in_transit.h"
20 #include "mojo/system/system_impl_export.h"
25 class ChannelEndpoint;
28 // This is an interface to one of the ends of a message pipe, and is used by
29 // |MessagePipe|. Its most important role is to provide a sink for messages
30 // (i.e., a place where messages can be sent). It has a secondary role: When the
31 // endpoint is local (i.e., in the current process), there'll be a dispatcher
32 // corresponding to the endpoint. In that case, the implementation of
33 // |MessagePipeEndpoint| also implements the functionality required by the
34 // dispatcher, e.g., to read messages and to wait. Implementations of this class
35 // are not thread-safe; instances are protected by |MesssagePipe|'s lock.
36 class MOJO_SYSTEM_IMPL_EXPORT MessagePipeEndpoint {
38 virtual ~MessagePipeEndpoint() {}
40 enum Type { kTypeLocal, kTypeProxy };
41 virtual Type GetType() const = 0;
43 // All implementations must implement these.
44 // Returns false if the endpoint should be closed and destroyed, else true.
45 virtual bool OnPeerClose() = 0;
46 // Implements |MessagePipe::EnqueueMessage()|. The major differences are that:
47 // a) Dispatchers have been vetted and cloned/attached to the message.
48 // b) At this point, we cannot report failure (if, e.g., a channel is torn
49 // down at this point, we should silently swallow the message).
50 virtual void EnqueueMessage(scoped_ptr<MessageInTransit> message) = 0;
52 // Implementations must override these if they represent a local endpoint,
53 // i.e., one for which there's a |MessagePipeDispatcher| (and thus a handle).
54 // An implementation for a proxy endpoint (for which there's no dispatcher)
55 // needs not override these methods, since they should never be called.
57 // These methods implement the methods of the same name in |MessagePipe|,
58 // though |MessagePipe|'s implementation may have to do a little more if the
59 // operation involves both endpoints.
61 virtual void CancelAllWaiters();
62 virtual MojoResult ReadMessage(UserPointer<void> bytes,
63 UserPointer<uint32_t> num_bytes,
64 DispatcherVector* dispatchers,
65 uint32_t* num_dispatchers,
66 MojoReadMessageFlags flags);
67 virtual HandleSignalsState GetHandleSignalsState() const;
68 virtual MojoResult AddWaiter(Waiter* waiter,
69 MojoHandleSignals signals,
71 HandleSignalsState* signals_state);
72 virtual void RemoveWaiter(Waiter* waiter, HandleSignalsState* signals_state);
74 // Implementations must override these if they represent a proxy endpoint. An
75 // implementation for a local endpoint needs not override these methods, since
76 // they should never be called.
77 virtual void Attach(ChannelEndpoint* channel_endpoint);
80 MessagePipeEndpoint() {}
83 DISALLOW_COPY_AND_ASSIGN(MessagePipeEndpoint);
89 #endif // MOJO_SYSTEM_MESSAGE_PIPE_ENDPOINT_H_