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 #include "ipc/ipc_platform_file.h" 6 7 #if defined(OS_POSIX) 8 #include <unistd.h> 9 #endif 10 11 namespace IPC { 12 GetFileHandleForProcess(base::PlatformFile handle,base::ProcessHandle process,bool close_source_handle)13 PlatformFileForTransit GetFileHandleForProcess(base::PlatformFile handle, 14 base::ProcessHandle process, 15 bool close_source_handle) { 16 IPC::PlatformFileForTransit out_handle; 17 #if defined(OS_WIN) 18 DWORD options = DUPLICATE_SAME_ACCESS; 19 if (close_source_handle) 20 options |= DUPLICATE_CLOSE_SOURCE; 21 if (handle == INVALID_HANDLE_VALUE || 22 !::DuplicateHandle(::GetCurrentProcess(), 23 handle, 24 process, 25 &out_handle, 26 0, 27 FALSE, 28 options)) { 29 out_handle = IPC::InvalidPlatformFileForTransit(); 30 } 31 #elif defined(OS_POSIX) 32 // If asked to close the source, we can simply re-use the source fd instead of 33 // dup()ing and close()ing. 34 // When we're not closing the source, we need to duplicate the handle and take 35 // ownership of that. The reason is that this function is often used to 36 // generate IPC messages, and the handle must remain valid until it's sent to 37 // the other process from the I/O thread. Without the dup, calling code might 38 // close the source handle before the message is sent, creating a race 39 // condition. 40 int fd = close_source_handle ? handle : ::dup(handle); 41 out_handle = base::FileDescriptor(fd, true); 42 #else 43 #error Not implemented. 44 #endif 45 return out_handle; 46 } 47 TakeFileHandleForProcess(base::File file,base::ProcessHandle process)48 PlatformFileForTransit TakeFileHandleForProcess(base::File file, 49 base::ProcessHandle process) { 50 return GetFileHandleForProcess(file.TakePlatformFile(), process, true); 51 } 52 53 } // namespace IPC 54