/*---------------------------------------------------------------
 * Copyright (c) 1999,2000,2001,2002,2003
 * The Board of Trustees of the University of Illinois
 * All Rights Reserved.
 *---------------------------------------------------------------
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 * obtaining a copy of this software (Iperf) and associated
 * documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the
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 * 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:
 *
 *
 * Redistributions of source code must retain the above
 * copyright notice, this list of conditions and
 * the following disclaimers.
 *
 *
 * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following
 * disclaimers in the documentation and/or other materials
 * provided with the distribution.
 *
 *
 * Neither the names of the University of Illinois, NCSA,
 * nor the names of its contributors may be used to endorse
 * or promote products derived from this Software without
 * specific prior written permission.
 *
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 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * ________________________________________________________________
 * National Laboratory for Applied Network Research
 * National Center for Supercomputing Applications
 * University of Illinois at Urbana-Champaign
 * http://www.ncsa.uiuc.edu
 * ________________________________________________________________
 *
 * Mutex.h
 * by Mark Gates <mgates@nlanr.net>
 * -------------------------------------------------------------------
 * An abstract class for locking a mutex (mutual exclusion). If
 * threads are not available, this does nothing.
 * ------------------------------------------------------------------- */
#ifndef MUTEX_H
#define MUTEX_H

#include "headers.h"

#if   defined( HAVE_POSIX_THREAD )
    typedef pthread_mutex_t Mutex;
#elif defined( HAVE_WIN32_THREAD )
    typedef HANDLE Mutex;
#else
    typedef int Mutex;
#endif

/* ------------------------------------------------------------------- *
class Mutex {
public:*/

    // initialize mutex
#if   defined( HAVE_POSIX_THREAD )
    #define Mutex_Initialize( MutexPtr ) pthread_mutex_init( MutexPtr, NULL )
#elif defined( HAVE_WIN32_THREAD )
    #define Mutex_Initialize( MutexPtr ) *MutexPtr = CreateMutex( NULL, 0, NULL )
#else
    #define Mutex_Initialize( MutexPtr )
#endif

    // lock the mutex variable
#if   defined( HAVE_POSIX_THREAD )
    #define Mutex_Lock( MutexPtr ) pthread_mutex_lock( MutexPtr )
#elif defined( HAVE_WIN32_THREAD )
    #define Mutex_Lock( MutexPtr ) WaitForSingleObject( *MutexPtr, INFINITE )
#else
    #define Mutex_Lock( MutexPtr )
#endif

    // unlock the mutex variable
#if   defined( HAVE_POSIX_THREAD )
    #define Mutex_Unlock( MutexPtr ) pthread_mutex_unlock( MutexPtr )
#elif defined( HAVE_WIN32_THREAD )
    #define Mutex_Unlock( MutexPtr ) ReleaseMutex( *MutexPtr )
#else
    #define Mutex_Unlock( MutexPtr )
#endif

    // destroy, making sure mutex is unlocked
#if   defined( HAVE_POSIX_THREAD )
    #define Mutex_Destroy( MutexPtr )  do {         \
        int rc = pthread_mutex_destroy( MutexPtr ); \
        if ( rc == EBUSY ) {                        \
            Mutex_Unlock( MutexPtr );               \
            pthread_mutex_destroy( MutexPtr );      \
        }                                           \
    } while ( 0 )
#elif defined( HAVE_WIN32_THREAD )
    #define Mutex_Destroy( MutexPtr ) CloseHandle( *MutexPtr )
#else
    #define Mutex_Destroy( MutexPtr )
#endif

#endif // MUTEX_H