mojo/edk/system/endpoint_relayer.h

   1 // Copyright 2014 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.
   4
   5 #ifndef MOJO_EDK_SYSTEM_ENDPOINT_RELAYER_H_
   6 #define MOJO_EDK_SYSTEM_ENDPOINT_RELAYER_H_
   7
   8 #include "base/macros.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/synchronization/lock.h"
  11 #include "mojo/edk/system/channel_endpoint_client.h"
  12 #include "mojo/edk/system/system_impl_export.h"
  13
  14 namespace mojo {
  15 namespace system {
  16
  17 class ChannelEndpoint;
  18
  19 // This is a simple |ChannelEndpointClient| that just relays messages between
  20 // two |ChannelEndpoint|s (without the overhead of |MessagePipe|).
  21 class MOJO_SYSTEM_IMPL_EXPORT EndpointRelayer : public ChannelEndpointClient {
  22  public:
  23   EndpointRelayer();
  24
  25   // Gets the other port number (i.e., 0 -> 1, 1 -> 0).
  26   static unsigned GetPeerPort(unsigned port);
  27
  28   // Initialize this object. This must be called before any other method.
  29   void Init(ChannelEndpoint* endpoint0, ChannelEndpoint* endpoint1);
  30
  31   // |ChannelEndpointClient| methods:
  32   bool OnReadMessage(unsigned port, MessageInTransit* message) override;
  33   void OnDetachFromChannel(unsigned port) override;
  34
  35  private:
  36   virtual ~EndpointRelayer();
  37
  38   // TODO(vtl): We could probably get away without the lock if we had a
  39   // thread-safe |scoped_refptr|.
  40   base::Lock lock_;  // Protects the following members.
  41   scoped_refptr<ChannelEndpoint> endpoints_[2];
  42
  43   DISALLOW_COPY_AND_ASSIGN(EndpointRelayer);
  44 };
  45
  46 }  // namespace system
  47 }  // namespace mojo
  48
  49 #endif  // MOJO_EDK_SYSTEM_ENDPOINT_RELAYER_H_