Condition

/* -*-c++-*- OpenThreads library, Copyright (C) 2002 - 2007  The Open Thread Group
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * 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 
 * OpenSceneGraph Public License for more details.
*/


//
// Condition - C++ condition class
// ~~~~~~~~~
//

#ifndef _OPENTHREADS_CONDITION_
#define _OPENTHREADS_CONDITION_

#include <OpenThreads/Exports>
#include <OpenThreads/Mutex>

namespace OpenThreads {

/**
 *  @class Condition
 *  @brief  This class provides an object-oriented thread condition interface.
 */
class OPENTHREAD_EXPORT_DIRECTIVE Condition {

public:

    /**
     *  Constructor
     */
    Condition();

    /**
     *  Destructor
     */
    virtual ~Condition();

    /**
     *  Wait on a mutex.
     */
    virtual int wait(Mutex *mutex);

    /**
     *  Wait on a mutex for a given amount of time (ms)
     *
     *  @return 0 if normal, -1 if errno set, errno code otherwise.
     */
    virtual int wait(Mutex *mutex, unsigned long int ms);

    /**
     *  Signal a SINGLE thread to wake if it's waiting.
     *
     *  @return 0 if normal, -1 if errno set, errno code otherwise.
     */
    virtual int signal();

    /**
     *  Wake all threads waiting on this condition.
     *
     *  @return 0 if normal, -1 if errno set, errno code otherwise.
     */
    virtual int broadcast();

private:

    /**
     *  Private copy constructor, to prevent tampering.
     */
    Condition(const Condition &/*c*/) {};

    /**
     *  Private copy assignment, to prevent tampering.
     */
    Condition &operator=(const Condition &/*c*/) {return *(this);};

    /**
     *  Implementation-specific data
     */
    void *_prvData;

};

}

#endif // !_OPENTHREADS_CONDITION_