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 IPC_IPC_CHANNEL_HANDLE_H_ 6#define IPC_IPC_CHANNEL_HANDLE_H_ 7 8#include <string> 9 10#include "build/build_config.h" 11#include "mojo/public/cpp/system/message_pipe.h" 12 13#if defined(OS_POSIX) 14#include "base/file_descriptor_posix.h" 15#elif defined(OS_WIN) 16#include <windows.h> 17#endif // defined (OS_WIN) 18 19// On Windows, any process can create an IPC channel and others can fetch 20// it by name. We pass around the channel names over IPC. 21// On Windows the initialization of ChannelHandle with an existing pipe 22// handle is provided for convenience. 23// NOTE: A ChannelHandle with a pipe handle Will NOT be marshalled over IPC. 24 25// On POSIX, we instead pass around handles to channel endpoints via IPC. 26// When it's time to IPC a new channel endpoint around, we send both the 27// channel name as well as a base::FileDescriptor, which is itself a special 28// type that knows how to copy a socket endpoint over IPC. 29// 30// In sum, this data structure can be used to pass channel information by name 31// in both Windows and Posix. When passing a handle to a channel over IPC, 32// use this data structure only for POSIX. 33 34namespace IPC { 35 36struct ChannelHandle { 37 // Note that serialization for this object is defined in the ParamTraits 38 // template specialization in ipc_message_utils.h. 39 ChannelHandle() {} 40 // The name that is passed in should be an absolute path for Posix. 41 // Otherwise there may be a problem in IPC communication between 42 // processes with different working directories. 43 ChannelHandle(const std::string& n) : name(n) {} 44 ChannelHandle(const char* n) : name(n) {} 45#if defined(OS_WIN) 46 explicit ChannelHandle(HANDLE h) : pipe(h) {} 47#elif defined(OS_POSIX) 48 ChannelHandle(const std::string& n, const base::FileDescriptor& s) 49 : name(n), socket(s) {} 50#endif // defined(OS_POSIX) 51 ChannelHandle(mojo::MessagePipeHandle h) : mojo_handle(h) {} 52 53 std::string name; 54#if defined(OS_POSIX) 55 base::FileDescriptor socket; 56#elif defined(OS_WIN) 57 // A simple container to automatically initialize pipe handle 58 struct PipeHandle { 59 PipeHandle() : handle(NULL) {} 60 PipeHandle(HANDLE h) : handle(h) {} 61 HANDLE handle; 62 }; 63 PipeHandle pipe; 64#endif // defined (OS_WIN) 65 mojo::MessagePipeHandle mojo_handle; 66}; 67 68} // namespace IPC 69 70#endif // IPC_IPC_CHANNEL_HANDLE_H_ 71