content/common/child_process_host_impl.h

   1 // Copyright (c) 2011 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 #pragma once
   8
   9 #include <string>
  10 #include <vector>
  11
  12 #include "build/build_config.h"
  13
  14 #include "base/basictypes.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/memory/singleton.h"
  17 #include "base/shared_memory.h"
  18 #include "base/string16.h"
  19 #include "content/public/common/child_process_host.h"
  20
  21 class FilePath;
  22
  23 namespace content {
  24 class ChildProcessHostDelegate;
  25
  26 // Provides common functionality for hosting a child process and processing IPC
  27 // messages between the host and the child process. Users are responsible
  28 // for the actual launching and terminating of the child processes.
  29 class CONTENT_EXPORT ChildProcessHostImpl : public ChildProcessHost,
  30                                             public IPC::Channel::Listener {
  31  public:
  32   virtual ~ChildProcessHostImpl();
  33
  34   // Public and static for reuse by RenderMessageFilter.
  35   static void AllocateSharedMemory(
  36       uint32 buffer_size, base::ProcessHandle child_process,
  37       base::SharedMemoryHandle* handle);
  38
  39   // Generates a unique channel name for a child process.
  40   // The "instance" pointer value is baked into the channel id.
  41   static std::string GenerateRandomChannelID(void* instance);
  42
  43   // Returns a unique ID to identify a child process. On construction, this
  44   // function will be used to generate the id_, but it is also used to generate
  45   // IDs for the RenderProcessHost, which doesn't inherit from us, and whose IDs
  46   // must be unique for all child processes.
  47   //
  48   // This function is threadsafe since RenderProcessHost is on the UI thread,
  49   // but normally this will be used on the IO thread.
  50   static int GenerateChildProcessUniqueId();
  51
  52   // ChildProcessHost implementation
  53   virtual bool Send(IPC::Message* message) OVERRIDE;
  54   virtual void ForceShutdown() OVERRIDE;
  55   virtual std::string CreateChannel() OVERRIDE;
  56   virtual bool IsChannelOpening() OVERRIDE;
  57   virtual void AddFilter(IPC::ChannelProxy::MessageFilter* filter) OVERRIDE;
  58 #if defined(OS_POSIX)
  59   virtual int TakeClientFileDescriptor() OVERRIDE;
  60 #endif
  61
  62  private:
  63   friend class ChildProcessHost;
  64
  65   explicit ChildProcessHostImpl(ChildProcessHostDelegate* delegate);
  66
  67   // IPC::Channel::Listener methods:
  68   virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
  69   virtual void OnChannelConnected(int32 peer_pid) OVERRIDE;
  70   virtual void OnChannelError() OVERRIDE;
  71
  72   // Message handlers:
  73   void OnShutdownRequest();
  74   void OnAllocateSharedMemory(uint32 buffer_size,
  75                               base::SharedMemoryHandle* handle);
  76
  77   ChildProcessHostDelegate* delegate_;
  78   base::ProcessHandle peer_handle_;
  79   bool opening_channel_;  // True while we're waiting the channel to be opened.
  80   scoped_ptr<IPC::Channel> channel_;
  81   std::string channel_id_;
  82
  83   // Holds all the IPC message filters.  Since this object lives on the IO
  84   // thread, we don't have a IPC::ChannelProxy and so we manage filters
  85   // manually.
  86   std::vector<scoped_refptr<IPC::ChannelProxy::MessageFilter> > filters_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(ChildProcessHostImpl);
  89 };
  90
  91 }  // namespace content
  92
  93 #endif  // CONTENT_COMMON_CHILD_PROCESS_HOST_IMPL_H_