/security/nss/lib/pk11wrap/pk11list.c

  1/* ***** BEGIN LICENSE BLOCK *****
  2 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  3 *
  4 * The contents of this file are subject to the Mozilla Public License Version
  5 * 1.1 (the "License"); you may not use this file except in compliance with
  6 * the License. You may obtain a copy of the License at
  7 * http://www.mozilla.org/MPL/
  8 *
  9 * Software distributed under the License is distributed on an "AS IS" basis,
 10 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 11 * for the specific language governing rights and limitations under the
 12 * License.
 13 *
 14 * The Original Code is the Netscape security libraries.
 15 *
 16 * The Initial Developer of the Original Code is
 17 * Netscape Communications Corporation.
 18 * Portions created by the Initial Developer are Copyright (C) 1994-2000
 19 * the Initial Developer. All Rights Reserved.
 20 *
 21 * Contributor(s):
 22 *
 23 * Alternatively, the contents of this file may be used under the terms of
 24 * either the GNU General Public License Version 2 or later (the "GPL"), or
 25 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 26 * in which case the provisions of the GPL or the LGPL are applicable instead
 27 * of those above. If you wish to allow use of your version of this file only
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 29 * use your version of this file under the terms of the MPL, indicate your
 30 * decision by deleting the provisions above and replace them with the notice
 31 * and other provisions required by the GPL or the LGPL. If you do not delete
 32 * the provisions above, a recipient may use your version of this file under
 33 * the terms of any one of the MPL, the GPL or the LGPL.
 34 *
 35 * ***** END LICENSE BLOCK ***** */
 36/*
 37 * Locking and queue management primatives
 38 *
 39 */
 40
 41#include "seccomon.h"
 42#include "nssilock.h"
 43#include "secmod.h"
 44#include "secmodi.h"
 45#include "secmodti.h"
 46#include "nssrwlk.h"
 47
 48/*
 49 * create a new lock for a Module List
 50 */
 51SECMODListLock *SECMOD_NewListLock()
 52{
 53    return NSSRWLock_New( 10, "moduleListLock");
 54}
 55
 56/*
 57 * destroy the lock
 58 */
 59void SECMOD_DestroyListLock(SECMODListLock *lock) 
 60{
 61    NSSRWLock_Destroy(lock);
 62}
 63
 64
 65/*
 66 * Lock the List for Read: NOTE: this assumes the reading isn't so common
 67 * the writing will be starved.
 68 */
 69void SECMOD_GetReadLock(SECMODListLock *modLock) 
 70{
 71    NSSRWLock_LockRead(modLock);
 72}
 73
 74/*
 75 * Release the Read lock
 76 */
 77void SECMOD_ReleaseReadLock(SECMODListLock *modLock) 
 78{
 79    NSSRWLock_UnlockRead(modLock);
 80}
 81
 82
 83/*
 84 * lock the list for Write
 85 */
 86void SECMOD_GetWriteLock(SECMODListLock *modLock) 
 87{
 88    NSSRWLock_LockWrite(modLock);
 89}
 90
 91
 92/*
 93 * Release the Write Lock: NOTE, this code is pretty inefficient if you have
 94 * lots of write collisions.
 95 */
 96void SECMOD_ReleaseWriteLock(SECMODListLock *modLock) 
 97{
 98    NSSRWLock_UnlockWrite(modLock);
 99}
100
101
102/*
103 * must Hold the Write lock
104 */
105void
106SECMOD_RemoveList(SECMODModuleList **parent, SECMODModuleList *child) 
107{
108    *parent = child->next;
109    child->next = NULL;
110}
111
112/*
113 * if lock is not specified, it must already be held
114 */
115void
116SECMOD_AddList(SECMODModuleList *parent, SECMODModuleList *child, 
117							SECMODListLock *lock) 
118{
119    if (lock) { SECMOD_GetWriteLock(lock); }
120
121    child->next = parent->next;
122    parent->next = child;
123
124   if (lock) { SECMOD_ReleaseWriteLock(lock); }
125}
126
127