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