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      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 gfx {
     26 struct GpuMemoryBufferHandle;
     27 }
     28 
     29 namespace IPC {
     30 class MessageFilter;
     31 }
     32 
     33 namespace content {
     34 class ChildProcessHostDelegate;
     35 
     36 // Provides common functionality for hosting a child process and processing IPC
     37 // messages between the host and the child process. Users are responsible
     38 // for the actual launching and terminating of the child processes.
     39 class CONTENT_EXPORT ChildProcessHostImpl : public ChildProcessHost,
     40                                             public IPC::Listener {
     41  public:
     42   virtual ~ChildProcessHostImpl();
     43 
     44   // Public and static for reuse by RenderMessageFilter.
     45   static void AllocateSharedMemory(
     46       size_t buffer_size, base::ProcessHandle child_process,
     47       base::SharedMemoryHandle* handle);
     48 
     49   // Returns a unique ID to identify a child process. On construction, this
     50   // function will be used to generate the id_, but it is also used to generate
     51   // IDs for the RenderProcessHost, which doesn't inherit from us, and whose IDs
     52   // must be unique for all child processes.
     53   //
     54   // This function is threadsafe since RenderProcessHost is on the UI thread,
     55   // but normally this will be used on the IO thread.
     56   //
     57   // This will never return ChildProcessHost::kInvalidUniqueID.
     58   static int GenerateChildProcessUniqueId();
     59 
     60   // ChildProcessHost implementation
     61   virtual bool Send(IPC::Message* message) OVERRIDE;
     62   virtual void ForceShutdown() OVERRIDE;
     63   virtual std::string CreateChannel() OVERRIDE;
     64   virtual bool IsChannelOpening() OVERRIDE;
     65   virtual void AddFilter(IPC::MessageFilter* filter) OVERRIDE;
     66 #if defined(OS_POSIX)
     67   virtual int TakeClientFileDescriptor() OVERRIDE;
     68 #endif
     69 
     70  private:
     71   friend class ChildProcessHost;
     72 
     73   explicit ChildProcessHostImpl(ChildProcessHostDelegate* delegate);
     74 
     75   // IPC::Listener methods:
     76   virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
     77   virtual void OnChannelConnected(int32 peer_pid) OVERRIDE;
     78   virtual void OnChannelError() OVERRIDE;
     79   virtual void OnBadMessageReceived(const IPC::Message& message) OVERRIDE;
     80 
     81   // Message handlers:
     82   void OnShutdownRequest();
     83   void OnAllocateSharedMemory(uint32 buffer_size,
     84                               base::SharedMemoryHandle* handle);
     85   void OnAllocateGpuMemoryBuffer(uint32 width,
     86                                  uint32 height,
     87                                  uint32 internalformat,
     88                                  uint32 usage,
     89                                  gfx::GpuMemoryBufferHandle* handle);
     90 
     91   ChildProcessHostDelegate* delegate_;
     92   base::ProcessHandle peer_handle_;
     93   bool opening_channel_;  // True while we're waiting the channel to be opened.
     94   scoped_ptr<IPC::Channel> channel_;
     95   std::string channel_id_;
     96 
     97   // Holds all the IPC message filters.  Since this object lives on the IO
     98   // thread, we don't have a IPC::ChannelProxy and so we manage filters
     99   // manually.
    100   std::vector<scoped_refptr<IPC::MessageFilter> > filters_;
    101 
    102   DISALLOW_COPY_AND_ASSIGN(ChildProcessHostImpl);
    103 };
    104 
    105 }  // namespace content
    106 
    107 #endif  // CONTENT_COMMON_CHILD_PROCESS_HOST_IMPL_H_
    108