source: trunk/synergy/lib/mt/CMutex.h@ 3472

/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2002 Chris Schoeneman
 * 
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file COPYING that should have accompanied this file.
 * 
 * This package 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.
 */

#ifndef CMUTEX_H
#define CMUTEX_H

#include "IArchMultithread.h"

//! Mutual exclusion
/*!
A non-recursive mutual exclusion object.  Only one thread at a time can
hold a lock on a mutex.  Any thread that attempts to lock a locked mutex
will block until the mutex is unlocked.  At that time, if any threads are
blocked, exactly one waiting thread will acquire the lock and continue
running.  A thread may not lock a mutex it already owns the lock on;  if
it tries it will deadlock itself.
*/
class CMutex {
public:
        CMutex();
        //! Equivalent to default c'tor
        /*!
        Copy c'tor doesn't copy anything.  It just makes it possible to
        copy objects that contain a mutex.
        */
        CMutex(const CMutex&);
        ~CMutex();

        //! @name manipulators
        //@{

        //! Does nothing
        /*!
        This does nothing.  It just makes it possible to assign objects
        that contain a mutex.
        */
        CMutex&                         operator=(const CMutex&);

        //@}
        //! @name accessors
        //@{

        //! Lock the mutex
        /*!
        Locks the mutex, which must not have been previously locked by the
        calling thread.  This blocks if the mutex is already locked by another
        thread.

        (cancellation point)
        */
        void                            lock() const;

        //! Unlock the mutex
        /*!
        Unlocks the mutex, which must have been previously locked by the
        calling thread.
        */
        void                            unlock() const;

        //@}

private:
        friend class CCondVarBase;
        CArchMutex                      m_mutex;
};

#endif