/*
 *  ZThreads, a platform-independant, multithreading and 
 *  synchroniation library
 *
 *  Copyright (C) 2001, 2002 Eric Crahen, See LGPL.TXT for details
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 *  SUNY @ Buffalo, hereby disclaims all copyright interest in the
 *  ZThreads library written by Eric Crahen
 */

#ifndef __ZTTSS_H__
#define __ZTTSS_H__

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

namespace ZThread {

/**
 * @class TSS
 * @author Eric Crahen <crahen@cse.buffalo.edu>
 * @date <2002-05-24T11:35:42-0400>
 * @version 2.1.6
 *
 * An abstraction for dealing with POSIX thread specific storage (tss). 
 * Provides get/set and creation/destruction.
 */
template <typename T>
class TSS : private NonCopyable {
  
  pthread_key_t _key;

 public:

  /**
   * Create a new object for accessing tss. 
   */
  TSS() {

    if(pthread_key_create(&_key, 0) != 0) {
      assert(0); // Key creation failed
    }

  }

 /**
  * Destroy the underlying supoprt for accessing tss with this 
  * object.
  */
  ~TSS() {
  
    pthread_key_delete(_key);
    
  }
 
  /**
   * Get the value stored in tss.
   *
   * @return T
   *
   * @exception InvalidOp_exception thrown when the tss is not properly initialized
   */
  T get() const {
    return reinterpret_cast<T>(pthread_getspecific(_key));
  }
  
 
  /**
   * Store a value in tss.
   *
   * @param value T
   * @return T old value
   *
   * @exception InvalidOp_exception thrown when the tss is not properly initialized
   */
  T set(T value) const {

    T oldValue = get();
    pthread_setspecific(_key, value);
    
    return oldValue;
    
  }
   
};

};

#endif


