/*
 * Copyright (c) 2005, Eric Crahen
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is furnished
 * to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#ifndef __ZTFASTRECURSIVELOCK_H__
#define __ZTFASTRECURSIVELOCK_H__

#include "zthread/NonCopyable.h"
#include <pthread.h>

namespace ZThread {

/**
 * @class FastRecursiveLock
 *
 * @author Eric Crahen <http://www.code-foo.com>
 * @date <2003-07-16T23:31:23-0400>
 * @version 2.2.0
 *
 * This FastRecursiveLock implementation uses pthreads mutex attribute 
 * functions to create a recursive lock. This implementation is not 
 * specific to solaris and will work on any system that supports 
 * pthread_mutexattr_settype().  
 */ 
class FastRecursiveLock : private NonCopyable {
    
  pthread_mutex_t _mtx;

  /**
   * @class Attribute
   *
   * Utility class to maintain the attribute as long as it is needed.
   */
  class Attribute {
    
    pthread_mutexattr_t _attr;

  public:

    Attribute() {

      if(pthread_mutexattr_init(&_attr) != 0) {
        assert(0);
      }
      
      if(pthread_mutexattr_settype(&_attr, PTHREAD_MUTEX_RECURSIVE) != 0) {
        assert(0);
      }

    }
    
    ~Attribute() {

      if(pthread_mutexattr_destroy(&_attr) != 0) {
        assert(0);
      }

    }

    operator pthread_mutexattr_t*() {
      return &_attr;
    }

  };

public:

  inline FastRecursiveLock() {
    
    static Attribute attr;
    pthread_mutex_init(&_mtx, (pthread_mutexattr_t*)attr);

  }
  
  inline ~FastRecursiveLock() {

    pthread_mutex_destroy(&_mtx);

  }
  
  inline void acquire() {
    
    pthread_mutex_lock(&_mtx);

  }

  inline void release() {
    
    pthread_mutex_unlock(&_mtx);
    
  }
  
  inline bool tryAcquire(unsigned long timeout=0) {

    return (pthread_mutex_trylock(&_mtx) == 0);

  }
  
}; /* FastRecursiveLock */


} // namespace ZThread

#endif