tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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pk11list.c (1803B)

      1 /* This Source Code Form is subject to the terms of the Mozilla Public
      2 * License, v. 2.0. If a copy of the MPL was not distributed with this
      3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      4 /*
      5 * Locking and queue management primatives
      6 *
      7 */
      8 
      9 #include "seccomon.h"
     10 #include "nssilock.h"
     11 #include "secmod.h"
     12 #include "secmodi.h"
     13 #include "secmodti.h"
     14 #include "nssrwlk.h"
     15 
     16 /*
     17 * create a new lock for a Module List
     18 */
     19 SECMODListLock *
     20 SECMOD_NewListLock()
     21 {
     22    return NSSRWLock_New(10, "moduleListLock");
     23 }
     24 
     25 /*
     26 * destroy the lock
     27 */
     28 void
     29 SECMOD_DestroyListLock(SECMODListLock *lock)
     30 {
     31    NSSRWLock_Destroy(lock);
     32 }
     33 
     34 /*
     35 * Lock the list for reading.
     36 * Note: this uses a non-reentrant lock. Writers are given preference.
     37 */
     38 void
     39 SECMOD_GetReadLock(SECMODListLock *modLock)
     40 {
     41    NSSRWLock_LockRead(modLock);
     42 }
     43 
     44 /*
     45 * Release the Read lock
     46 */
     47 void
     48 SECMOD_ReleaseReadLock(SECMODListLock *modLock)
     49 {
     50    NSSRWLock_UnlockRead(modLock);
     51 }
     52 
     53 /*
     54 * lock the list for Write
     55 */
     56 void
     57 SECMOD_GetWriteLock(SECMODListLock *modLock)
     58 {
     59    NSSRWLock_LockWrite(modLock);
     60 }
     61 
     62 /*
     63 * Release the Write Lock: NOTE, this code is pretty inefficient if you have
     64 * lots of write collisions.
     65 */
     66 void
     67 SECMOD_ReleaseWriteLock(SECMODListLock *modLock)
     68 {
     69    NSSRWLock_UnlockWrite(modLock);
     70 }
     71 
     72 /*
     73 * must Hold the Write lock
     74 */
     75 void
     76 SECMOD_RemoveList(SECMODModuleList **parent, SECMODModuleList *child)
     77 {
     78    *parent = child->next;
     79    child->next = NULL;
     80 }
     81 
     82 /*
     83 * if lock is not specified, it must already be held
     84 */
     85 void
     86 SECMOD_AddList(SECMODModuleList *parent, SECMODModuleList *child,
     87               SECMODListLock *lock)
     88 {
     89    if (lock) {
     90        SECMOD_GetWriteLock(lock);
     91    }
     92 
     93    child->next = parent->next;
     94    parent->next = child;
     95 
     96    if (lock) {
     97        SECMOD_ReleaseWriteLock(lock);
     98    }
     99 }