semaphor.h

Go to the documentation of this file.

/*
 * semaphor.h
 *
 * Thread synchronisation semaphore class.
 *
 * Portable Tools Library
 *
 * Copyright (c) 1993-1998 Equivalence Pty. Ltd.
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Portable Windows Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Portions are Copyright (C) 1993 Free Software Foundation, Inc.
 * All Rights Reserved.
 *
 * Contributor(s): ______________________________________.
 */

#ifndef PTLIB_SEMAPHORE_H
#define PTLIB_SEMAPHORE_H

#ifdef P_USE_PRAGMA
#pragma interface
#endif

#include <ptlib/psync.h>
#include <limits.h>
#include <ptlib/atomic.h>

class PSemaphore : public PSync
{
  PCLASSINFO(PSemaphore, PSync);

  public:
    PSemaphore(
      unsigned initial = 0,         
      unsigned maximum = UINT_MAX   
    ) { Reset(initial, maximum); }

    PSemaphore(
      const PString & name,
      unsigned initial = 0,         
      unsigned maximum = UINT_MAX   
    ) : m_name(name) { Reset(initial, maximum); }

    PSemaphore(const PSemaphore & sem)
      : PSync()
      , m_name(sem.m_name)
    { Reset(sem.m_initial, sem.m_maximum); }

    ~PSemaphore();

    virtual void Wait();

    virtual PBoolean Wait(
      const PTimeInterval & timeout // Amount of time to wait for semaphore.
    );

    virtual void Signal();

    virtual void Reset(
      unsigned initial = 0,         
      unsigned maximum = UINT_MAX   
    );

    unsigned GetInitial() const  { return m_initial; }

    unsigned GetMaximum() const { return m_maximum; }


  protected:
    PString  m_name;
    unsigned m_maximum;
    unsigned m_initial;


// Include platform dependent part of class
#ifdef _WIN32
#include "msos/ptlib/semaphor.h"
#else
#include "unix/ptlib/semaphor.h"
#endif
};


#endif // PTLIB_SEMAPHORE_H


// End Of File ///////////////////////////////////////////////////////////////