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// Copyright 2012 The Chromium Authors
// 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 BUILDFLAG(IS_WIN)
#include <windows.h>
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
#include <unistd.h>
#include "base/posix/eintr_wrapper.h"
#endif
namespace IPC {
#if BUILDFLAG(IS_WIN)
PlatformFileForTransit::PlatformFileForTransit() : handle_(nullptr) {}
PlatformFileForTransit::PlatformFileForTransit(HANDLE handle)
: handle_(handle) {}
bool PlatformFileForTransit::operator==(
const PlatformFileForTransit& platform_file) const {
return handle_ == platform_file.handle_;
}
bool PlatformFileForTransit::operator!=(
const PlatformFileForTransit& platform_file) const {
return !(*this == platform_file);
}
HANDLE PlatformFileForTransit::GetHandle() const {
return handle_;
}
bool PlatformFileForTransit::IsValid() const {
return handle_ != nullptr;
}
#endif // BUILDFLAG(IS_WIN)
PlatformFileForTransit GetPlatformFileForTransit(base::PlatformFile handle,
bool close_source_handle) {
#if BUILDFLAG(IS_WIN)
HANDLE raw_handle = INVALID_HANDLE_VALUE;
DWORD options = DUPLICATE_SAME_ACCESS;
if (close_source_handle)
options |= DUPLICATE_CLOSE_SOURCE;
if (handle == INVALID_HANDLE_VALUE ||
!::DuplicateHandle(::GetCurrentProcess(), handle, ::GetCurrentProcess(),
&raw_handle, 0, FALSE, options)) {
return IPC::InvalidPlatformFileForTransit();
}
return IPC::PlatformFileForTransit(raw_handle);
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
// 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 : HANDLE_EINTR(::dup(handle));
return base::FileDescriptor(fd, true);
#endif
}
PlatformFileForTransit TakePlatformFileForTransit(base::File file) {
return GetPlatformFileForTransit(file.TakePlatformFile(), true);
}
} // namespace IPC
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