gecko-dev/security/nss/lib/util/nsslocks.c

106 строки
3.3 KiB
C

/*
* 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 security libraries.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1994-2000 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License Version 2 or later (the
* "GPL"), in which case the provisions of the GPL are applicable
* instead of those above. If you wish to allow use of your
* version of this file only under the terms of the GPL and not to
* allow others to use your version of this file under the MPL,
* indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by
* the GPL. If you do not delete the provisions above, a recipient
* may use your version of this file under either the MPL or the
* GPL.
*/
/*
* nsslocks.h - threadsafe functions to initialize lock pointers.
*
* NOTE - These are not public interfaces
*
* $Id: nsslocks.c,v 1.3 2001/01/30 21:02:28 wtc%netscape.com Exp $
*/
#include "seccomon.h"
#include "nsslocks.h"
#include "pratom.h"
#include "prthread.h"
/* Given the address of a (global) pointer to a PZLock,
* atomicly create the lock and initialize the (global) pointer,
* if it is not already created/initialized.
*/
SECStatus
__nss_InitLock( PZLock **ppLock, nssILockType ltype )
{
static PRInt32 initializers;
PORT_Assert( ppLock != NULL);
/* atomically initialize the lock */
while (!*ppLock) {
PRInt32 myAttempt = PR_AtomicIncrement(&initializers);
if (myAttempt == 1) {
*ppLock = PZ_NewLock(ltype);
(void) PR_AtomicDecrement(&initializers);
break;
}
PR_Sleep(PR_INTERVAL_NO_WAIT); /* PR_Yield() */
(void) PR_AtomicDecrement(&initializers);
}
return (*ppLock != NULL) ? SECSuccess : SECFailure;
}
SECStatus
nss_InitLock( PZLock **ppLock, nssILockType ltype )
{
return __nss_InitLock(ppLock, ltype);
}
/* Given the address of a (global) pointer to a PZMonitor,
* atomicly create the monitor and initialize the (global) pointer,
* if it is not already created/initialized.
*/
SECStatus
nss_InitMonitor(PZMonitor **ppMonitor, nssILockType ltype )
{
static PRInt32 initializers;
PORT_Assert( ppMonitor != NULL);
/* atomically initialize the lock */
while (!*ppMonitor) {
PRInt32 myAttempt = PR_AtomicIncrement(&initializers);
if (myAttempt == 1) {
*ppMonitor = PZ_NewMonitor(ltype);
(void) PR_AtomicDecrement(&initializers);
break;
}
PR_Sleep(PR_INTERVAL_NO_WAIT); /* PR_Yield() */
(void) PR_AtomicDecrement(&initializers);
}
return (*ppMonitor != NULL) ? SECSuccess : SECFailure;
}