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btlocks.c

/* -*- Mode: C++; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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 the Netscape Portable Runtime (NSPR).
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998-2000
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * ***** END LICENSE BLOCK ***** */

/*
** File:        btlocks.c
** Description: Implemenation for thread locks using bthreads
** Exports:     prlock.h
*/

#include "primpl.h"

#include <string.h>
#include <sys/time.h>

void
_PR_InitLocks (void)
{
}

PR_IMPLEMENT(PRLock*)
    PR_NewLock (void)
{
    PRLock *lock;
    status_t semresult;

    if (!_pr_initialized) _PR_ImplicitInitialization();

    lock = PR_NEWZAP(PRLock);
    if (lock != NULL) {

      lock->benaphoreCount = 0;
      lock->semaphoreID = create_sem( 0, "nsprLockSem" );
      if( lock->semaphoreID < B_NO_ERROR ) {

          PR_DELETE( lock );
          lock = NULL;
      }
    }

    return lock;
}

PR_IMPLEMENT(void)
    PR_DestroyLock (PRLock* lock)
{
    status_t result;

    PR_ASSERT(NULL != lock);
    result = delete_sem(lock->semaphoreID);
    PR_ASSERT(result == B_NO_ERROR);
    PR_DELETE(lock);
}

PR_IMPLEMENT(void)
    PR_Lock (PRLock* lock)
{
    PR_ASSERT(lock != NULL);

    if( atomic_add( &lock->benaphoreCount, 1 ) > 0 ) {

      if( acquire_sem(lock->semaphoreID ) != B_NO_ERROR ) {

          atomic_add( &lock->benaphoreCount, -1 );
          return;
      }
    }

    lock->owner = find_thread( NULL );
}

PR_IMPLEMENT(PRStatus)
    PR_Unlock (PRLock* lock)
{
    PR_ASSERT(lock != NULL);
    lock->owner = NULL;
    if( atomic_add( &lock->benaphoreCount, -1 ) > 1 ) {

      release_sem( lock->semaphoreID );
    }

    return PR_SUCCESS;
}

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