aria2/src/Lock.h

/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2013 Nils Maier
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 */
/* copyright --> */
#ifndef D_LOCK_H
#define D_LOCK_H

#if defined(_WIN32)
#include <windows.h>
#elif defined(ENABLE_PTHREAD)
#include <pthread.h>
#endif

namespace aria2 {

class Lock {
private:
#if defined(_WIN32)
  ::CRITICAL_SECTION section_;
#elif defined(ENABLE_PTHREAD)
  ::pthread_mutex_t mutex_;
#endif

public:
  Lock()
  {
#if defined(_WIN32)
    ::InitializeCriticalSection(&section_);
#elif defined(ENABLE_PTHREAD)
    mutex_ = PTHREAD_RECURSIVE_MUTEX_INITIALIZER;
#endif
  }

  ~Lock()
  {
#if defined(_WIN32)
    ::DeleteCriticalSection(&section_);
#elif defined(ENABLE_PTHREAD)
    ::pthread_mutex_destroy(&mutex_);
#endif
  }

  inline void aquire()
  {
#if defined(_WIN32)
    ::EnterCriticalSection(&section_);
#elif defined(ENABLE_PTHREAD)
    ::pthread_mutex_lock(&mutex_);
#endif
  }

  inline bool tryAquire()
  {
#if defined(_WIN32)
    return ::TryEnterCriticalSection(&section_) == TRUE;
#elif defined(ENABLE_PTHREAD)
    return ::pthread_mutex_trylock(&mutex_) == 0;
#else
    return true;
#endif
  }

  inline void release()
  {
#if defined(_WIN32)
    ::LeaveCriticalSection(&section_);
#elif defined(ENABLE_PTHREAD)
    ::pthread_mutex_unlock(&mutex_);
#endif
  }
};

class LockGuard {
private:
  Lock& lock_;

public:
  inline LockGuard(Lock& lock) : lock_(lock) { lock_.aquire(); }
  inline ~LockGuard() { lock_.release(); }
};

} // namespace aria2

#endif // D_LOCK_H