palemoon27/ipc/glue/SharedMemoryBasic_android.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: sw=2 ts=8 et :
 */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_ipc_SharedMemoryBasic_android_h
#define mozilla_ipc_SharedMemoryBasic_android_h

#include "base/file_descriptor_posix.h"

#include "SharedMemory.h"

//
// This is a low-level wrapper around platform shared memory.  Don't
// use it directly; use Shmem allocated through IPDL interfaces.
//

namespace mozilla {
namespace ipc {

class SharedMemoryBasic final : public SharedMemoryCommon<base::FileDescriptor>
{
public:
  SharedMemoryBasic();

  virtual bool SetHandle(const Handle& aHandle) override;

  virtual bool Create(size_t aNbytes) override;

  virtual bool Map(size_t nBytes) override;

  virtual void CloseHandle() override;

  virtual void* memory() const override
  {
    return mMemory;
  }

  virtual SharedMemoryType Type() const override
  {
    return TYPE_BASIC;
  }

  static Handle NULLHandle()
  {
    return Handle();
  }

  virtual bool IsHandleValid(const Handle &aHandle) const override
  {
    return aHandle.fd >= 0;
  }

  virtual bool ShareToProcess(base::ProcessId aProcessId,
                              Handle* aNewHandle) override;

private:
  ~SharedMemoryBasic();

  void Unmap();

  // The /dev/ashmem fd we allocate.
  int mShmFd;
  // Pointer to mapped region, null if unmapped.
  void *mMemory;
};

} // namespace ipc
} // namespace mozilla

#endif // ifndef mozilla_ipc_SharedMemoryBasic_android_h