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
21namespace base {
22class FilePath;
23}
24
25namespace gfx {
26struct GpuMemoryBufferHandle;
27}
28
29namespace IPC {
30class MessageFilter;
31}
32
33namespace content {
34class 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.
39class 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