ipc_platform_file.h

// Copyright (c) 2011 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.

#ifndef IPC_IPC_PLATFORM_FILE_H_
#define IPC_IPC_PLATFORM_FILE_H_

#include "base/files/file.h"
#include "base/process/process.h"
#include "build/build_config.h"
#include "ipc/ipc_export.h"

#if defined(OS_POSIX)
#include "base/file_descriptor_posix.h"
#endif

#if defined(OS_WIN)
#include "base/memory/shared_memory_handle.h"
#endif

namespace IPC {

#if defined(OS_WIN)
// The semantics for IPC transfer of a SharedMemoryHandle are exactly the same
// as for a PlatformFileForTransit. The object wraps a HANDLE, and has some
// metadata that indicates the process to which the HANDLE belongs.
using PlatformFileForTransit = base::SharedMemoryHandle;
#elif defined(OS_POSIX)
typedef base::FileDescriptor PlatformFileForTransit;
#endif

inline PlatformFileForTransit InvalidPlatformFileForTransit() {
#if defined(OS_WIN)
  return PlatformFileForTransit();
#elif defined(OS_POSIX)
  return base::FileDescriptor();
#endif
}

inline base::PlatformFile PlatformFileForTransitToPlatformFile(
    const PlatformFileForTransit& transit) {
#if defined(OS_WIN)
  return transit.GetHandle();
#elif defined(OS_POSIX)
  return transit.fd;
#endif
}

inline base::File PlatformFileForTransitToFile(
    const PlatformFileForTransit& transit) {
#if defined(OS_WIN)
  return base::File(transit.GetHandle());
#elif defined(OS_POSIX)
  return base::File(transit.fd);
#endif
}

// Creates a new handle that can be passed through IPC. The result must be
// passed to the IPC layer as part of a message, or else it will leak.
IPC_EXPORT PlatformFileForTransit GetPlatformFileForTransit(
    base::PlatformFile file,
    bool close_source_handle);

// Creates a new handle that can be passed through IPC. The result must be
// passed to the IPC layer as part of a message, or else it will leak.
// Note that this function takes ownership of |file|.
IPC_EXPORT PlatformFileForTransit TakePlatformFileForTransit(base::File file);

}  // namespace IPC

#endif  // IPC_IPC_PLATFORM_FILE_H_