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.
5 #ifndef CONTENT_PULIC_COMMON_CHILD_PROCESS_HOST_H_
6 #define CONTENT_PULIC_COMMON_CHILD_PROCESS_HOST_H_
8 #include "build/build_config.h"
9 #include "content/common/content_export.h"
10 #include "ipc/ipc_channel_proxy.h"
18 class ChildProcessHostDelegate;
20 // This represents a non-browser process. This can include traditional child
21 // processes like plugins, or an embedder could even use this for long lived
22 // processes that run independent of the browser process.
23 class CONTENT_EXPORT ChildProcessHost : public IPC::Sender {
25 virtual ~ChildProcessHost() {}
27 // Used to create a child process host. The delegate must outlive this object.
28 static ChildProcessHost* Create(
29 ChildProcessHostDelegate* delegate);
31 // These flags may be passed to GetChildPath in order to alter its behavior,
32 // causing it to return a child path more suited to a specific task.
34 // No special behavior requested.
38 // Indicates that the child execed after forking may be execced from
39 // /proc/self/exe rather than using the "real" app path. This prevents
40 // autoupdate from confusing us if it changes the file out from under us.
41 // You will generally want to set this on Linux, except when there is an
42 // override to the command line (for example, we're forking a renderer in
43 // gdb). In this case, you'd use GetChildPath to get the real executable
44 // file name, and then prepend the GDB command to the command line.
45 CHILD_ALLOW_SELF = 1 << 0,
46 #elif defined(OS_MACOSX)
48 // Requests that the child run in a process that does not have the
49 // PIE (position-independent executable) bit set, effectively disabling
50 // ASLR. For process types that need to allocate a large contiguous
51 // region, ASLR may not leave a large enough "hole" for the purpose. This
52 // option should be used sparingly, and only when absolutely necessary.
53 // This option is currently incompatible with CHILD_ALLOW_HEAP_EXECUTION.
54 CHILD_NO_PIE = 1 << 1,
56 // Requests that the child run in a process that does not protect the
57 // heap against execution. Normally, heap pages may be made executable
58 // with mprotect, so this mode should be used sparingly. It is intended
59 // for processes that may host plug-ins that expect an executable heap
60 // without having to call mprotect. This option is currently incompatible
62 CHILD_ALLOW_HEAP_EXECUTION = 1 << 2,
66 // Returns the pathname to be used for a child process. If a subprocess
67 // pathname was specified on the command line, that will be used. Otherwise,
68 // the default child process pathname will be returned. On most platforms,
69 // this will be the same as the currently-executing process.
71 // The |flags| argument accepts one or more flags such as CHILD_ALLOW_SELF
72 // and CHILD_ALLOW_HEAP_EXECUTION as defined above. Pass only CHILD_NORMAL
73 // if none of these special behaviors are required.
75 // On failure, returns an empty FilePath.
76 static base::FilePath GetChildPath(int flags);
78 // Send the shutdown message to the child process.
79 // Does not check with the delegate's CanShutdown.
80 virtual void ForceShutdown() = 0;
82 // Creates the IPC channel. Returns the channel id if it succeeded, an
83 // empty string otherwise
84 virtual std::string CreateChannel() = 0;
86 // Returns true iff the IPC channel is currently being opened;
87 virtual bool IsChannelOpening() = 0;
89 // Adds an IPC message filter. A reference will be kept to the filter.
90 virtual void AddFilter(IPC::ChannelProxy::MessageFilter* filter) = 0;
93 // See IPC::Channel::TakeClientFileDescriptor.
94 virtual int TakeClientFileDescriptor() = 0;
98 }; // namespace content
100 #endif // CONTENT_PULIC_COMMON_CHILD_PROCESS_HOST_H_