content/common/child_process_host_impl.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 CONTENT_COMMON_CHILD_PROCESS_HOST_IMPL_H_
   6 #define CONTENT_COMMON_CHILD_PROCESS_HOST_IMPL_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "build/build_config.h"
  12
  13 #include "base/basictypes.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/memory/shared_memory.h"
  16 #include "base/memory/singleton.h"
  17 #include "base/strings/string16.h"
  18 #include "content/public/common/child_process_host.h"
  19 #include "ipc/ipc_listener.h"
  20
  21 namespace base {
  22 class FilePath;
  23 }
  24
  25 namespace content {
  26 class ChildProcessHostDelegate;
  27
  28 // Provides common functionality for hosting a child process and processing IPC
  29 // messages between the host and the child process. Users are responsible
  30 // for the actual launching and terminating of the child processes.
  31 class CONTENT_EXPORT ChildProcessHostImpl : public ChildProcessHost,
  32                                             public IPC::Listener {
  33  public:
  34   virtual ~ChildProcessHostImpl();
  35
  36   // This value is guaranteed to never be returned by
  37   // GenerateChildProcessUniqueId() below.
  38   static int kInvalidChildProcessId;
  39
  40   // Public and static for reuse by RenderMessageFilter.
  41   static void AllocateSharedMemory(
  42       size_t buffer_size, base::ProcessHandle child_process,
  43       base::SharedMemoryHandle* handle);
  44
  45   // Returns a unique ID to identify a child process. On construction, this
  46   // function will be used to generate the id_, but it is also used to generate
  47   // IDs for the RenderProcessHost, which doesn't inherit from us, and whose IDs
  48   // must be unique for all child processes.
  49   //
  50   // This function is threadsafe since RenderProcessHost is on the UI thread,
  51   // but normally this will be used on the IO thread.
  52   static int GenerateChildProcessUniqueId();
  53
  54   // ChildProcessHost implementation
  55   virtual bool Send(IPC::Message* message) OVERRIDE;
  56   virtual void ForceShutdown() OVERRIDE;
  57   virtual std::string CreateChannel() OVERRIDE;
  58   virtual bool IsChannelOpening() OVERRIDE;
  59   virtual void AddFilter(IPC::ChannelProxy::MessageFilter* filter) OVERRIDE;
  60 #if defined(OS_POSIX)
  61   virtual int TakeClientFileDescriptor() OVERRIDE;
  62 #endif
  63
  64  private:
  65   friend class ChildProcessHost;
  66
  67   explicit ChildProcessHostImpl(ChildProcessHostDelegate* delegate);
  68
  69   // IPC::Listener methods:
  70   virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
  71   virtual void OnChannelConnected(int32 peer_pid) OVERRIDE;
  72   virtual void OnChannelError() OVERRIDE;
  73
  74   // Message handlers:
  75   void OnShutdownRequest();
  76   void OnAllocateSharedMemory(uint32 buffer_size,
  77                               base::SharedMemoryHandle* handle);
  78
  79   ChildProcessHostDelegate* delegate_;
  80   base::ProcessHandle peer_handle_;
  81   bool opening_channel_;  // True while we're waiting the channel to be opened.
  82   scoped_ptr<IPC::Channel> channel_;
  83   std::string channel_id_;
  84
  85   // Holds all the IPC message filters.  Since this object lives on the IO
  86   // thread, we don't have a IPC::ChannelProxy and so we manage filters
  87   // manually.
  88   std::vector<scoped_refptr<IPC::ChannelProxy::MessageFilter> > filters_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(ChildProcessHostImpl);
  91 };
  92
  93 }  // namespace content
  94
  95 #endif  // CONTENT_COMMON_CHILD_PROCESS_HOST_IMPL_H_