ppapi/proxy/proxy_channel.h

   1 // Copyright (c) 2012 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 PPAPI_PROXY_PROXY_CHANNEL_H_
   6 #define PPAPI_PROXY_PROXY_CHANNEL_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "base/process/process.h"
  10 #include "ipc/ipc_listener.h"
  11 #include "ipc/ipc_platform_file.h"
  12 #include "ipc/ipc_sender.h"
  13 #include "ipc/ipc_sync_channel.h"
  14 #include "ppapi/proxy/ppapi_proxy_export.h"
  15
  16 namespace base {
  17 class MessageLoopProxy;
  18 class WaitableEvent;
  19 }
  20
  21 namespace IPC {
  22 class TestSink;
  23 }
  24
  25 namespace ppapi {
  26 namespace proxy {
  27
  28 class PPAPI_PROXY_EXPORT ProxyChannel
  29     : public IPC::Listener,
  30       public IPC::Sender {
  31  public:
  32   class PPAPI_PROXY_EXPORT Delegate {
  33    public:
  34     virtual ~Delegate() {}
  35
  36     // Returns the dedicated message loop for processing IPC requests.
  37     virtual base::MessageLoopProxy* GetIPCMessageLoop() = 0;
  38
  39     // Returns the event object that becomes signalled when the main thread's
  40     // message loop exits.
  41     virtual base::WaitableEvent* GetShutdownEvent() = 0;
  42
  43     // Duplicates a handle to the provided object, returning one that is valid
  44     // on the other side of the channel. This is part of the delegate interface
  45     // because both sides of the channel may not have sufficient permission to
  46     // duplicate handles directly. The implementation must provide the same
  47     // guarantees as ProxyChannel::ShareHandleWithRemote below.
  48     virtual IPC::PlatformFileForTransit ShareHandleWithRemote(
  49         base::PlatformFile handle,
  50         base::ProcessId remote_pid,
  51         bool should_close_source) = 0;
  52   };
  53
  54   virtual ~ProxyChannel();
  55
  56   // Alternative to InitWithChannel() for unit tests that want to send all
  57   // messages sent via this channel to the given test sink. The test sink
  58   // must outlive this class. In this case, the peer PID will be the current
  59   // process ID.
  60   void InitWithTestSink(IPC::TestSink* test_sink);
  61
  62   // Shares a file handle (HANDLE / file descriptor) with the remote side. It
  63   // returns a handle that should be sent in exactly one IPC message. Upon
  64   // receipt, the remote side then owns that handle. Note: if sending the
  65   // message fails, the returned handle is properly closed by the IPC system. If
  66   // should_close_source is set to true, the original handle is closed by this
  67   // operation and should not be used again.
  68   IPC::PlatformFileForTransit ShareHandleWithRemote(
  69       base::PlatformFile handle,
  70       bool should_close_source);
  71
  72   // IPC::Sender implementation.
  73   virtual bool Send(IPC::Message* msg) OVERRIDE;
  74
  75   // IPC::Listener implementation.
  76   virtual void OnChannelError() OVERRIDE;
  77
  78   // Will be NULL in some unit tests and if the remote side has crashed.
  79   IPC::SyncChannel* channel() const {
  80     return channel_.get();
  81   }
  82
  83 #if defined(OS_POSIX) && !defined(OS_NACL)
  84   int TakeRendererFD();
  85 #endif
  86
  87  protected:
  88   explicit ProxyChannel();
  89
  90   // You must call this function before anything else. Returns true on success.
  91   // The delegate pointer must outlive this class, ownership is not
  92   // transferred.
  93   virtual bool InitWithChannel(Delegate* delegate,
  94                                base::ProcessId peer_pid,
  95                                const IPC::ChannelHandle& channel_handle,
  96                                bool is_client);
  97
  98   ProxyChannel::Delegate* delegate() const {
  99     return delegate_;
 100   }
 101
 102  private:
 103   // Non-owning pointer. Guaranteed non-NULL after init is called.
 104   ProxyChannel::Delegate* delegate_;
 105
 106   // PID of the remote process. Use this instead of the Channel::peer_pid since
 107   // this is set synchronously on construction rather than waiting on the
 108   // "hello" message from the peer (which introduces a race condition).
 109   base::ProcessId peer_pid_;
 110
 111   // When we're unit testing, this will indicate the sink for the messages to
 112   // be deposited so they can be inspected by the test. When non-NULL, this
 113   // indicates that the channel should not be used.
 114   IPC::TestSink* test_sink_;
 115
 116   // Will be null for some tests when there is a test_sink_, and if the
 117   // remote side has crashed.
 118   scoped_ptr<IPC::SyncChannel> channel_;
 119
 120   DISALLOW_COPY_AND_ASSIGN(ProxyChannel);
 121 };
 122
 123 }  // namespace proxy
 124 }  // namespace ppapi
 125
 126 #endif  // PPAPI_PROXY_PROXY_CHANNEL_H_