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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "build/build_config.h"
#include "ipc/ipc_platform_file.h"
#if defined(OS_POSIX)
#include <unistd.h>
#endif
namespace IPC {
PlatformFileForTransit GetFileHandleForProcess(base::PlatformFile handle,
base::ProcessHandle process,
bool close_source_handle) {
IPC::PlatformFileForTransit out_handle;
#if defined(OS_WIN)
DWORD options = DUPLICATE_SAME_ACCESS;
if (close_source_handle)
options |= DUPLICATE_CLOSE_SOURCE;
if (handle == INVALID_HANDLE_VALUE ||
!::DuplicateHandle(::GetCurrentProcess(),
handle,
process,
&out_handle,
0,
FALSE,
options)) {
out_handle = IPC::InvalidPlatformFileForTransit();
}
#elif defined(OS_POSIX)
// If asked to close the source, we can simply re-use the source fd instead of
// dup()ing and close()ing.
// When we're not closing the source, we need to duplicate the handle and take
// ownership of that. The reason is that this function is often used to
// generate IPC messages, and the handle must remain valid until it's sent to
// the other process from the I/O thread. Without the dup, calling code might
// close the source handle before the message is sent, creating a race
// condition.
int fd = close_source_handle ? handle : ::dup(handle);
out_handle = base::FileDescriptor(fd, true);
#else
#error Not implemented.
#endif
return out_handle;
}
PlatformFileForTransit TakeFileHandleForProcess(base::File file,
base::ProcessHandle process) {
return GetFileHandleForProcess(file.TakePlatformFile(), process, true);
}
} // namespace IPC
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