pjs/security/nss/lib/util/nsslocks.c

113 строки
3.7 KiB
C

/* ***** 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 security libraries.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1994-2000
* 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 ***** */
/*
* nsslocks.h - threadsafe functions to initialize lock pointers.
*
* NOTE - These are not public interfaces
*
* $Id: nsslocks.c,v 1.5 2004-04-25 15:03:17 gerv%gerv.net 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) {
if (!*ppLock) {
*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) {
if (!*ppMonitor) {
*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;
}