nsprpub/pr/include/prcmon.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef prcmon_h___
   7 #define prcmon_h___
   8
   9 /*
  10 ** Interface to cached monitors. Cached monitors use an address to find a
  11 ** given PR monitor. In this way a monitor can be associated with another
  12 ** object without preallocating a monitor for all objects.
  13 **
  14 ** A hash table is used to quickly map addresses to individual monitors
  15 ** and the system automatically grows the hash table as needed.
  16 **
  17 ** Cache monitors are about 5 times slower to use than uncached monitors.
  18 */
  19 #include "prmon.h"
  20 #include "prinrval.h"
  21
  22 PR_BEGIN_EXTERN_C
  23
  24 /**
  25 ** Like PR_EnterMonitor except use the "address" to find a monitor in the
  26 ** monitor cache. If successful, returns the PRMonitor now associated
  27 ** with "address". Note that you must PR_CExitMonitor the address to
  28 ** release the monitor cache entry (otherwise the monitor cache will fill
  29 ** up). This call will return NULL if the monitor cache needs to be
  30 ** expanded and the system is out of memory.
  31 */
  32 NSPR_API(PRMonitor*) PR_CEnterMonitor(void *address);
  33
  34 /*
  35 ** Like PR_ExitMonitor except use the "address" to find a monitor in the
  36 ** monitor cache.
  37 */
  38 NSPR_API(PRStatus) PR_CExitMonitor(void *address);
  39
  40 /*
  41 ** Like PR_Wait except use the "address" to find a monitor in the
  42 ** monitor cache.
  43 */
  44 NSPR_API(PRStatus) PR_CWait(void *address, PRIntervalTime timeout);
  45
  46 /*
  47 ** Like PR_Notify except use the "address" to find a monitor in the
  48 ** monitor cache.
  49 */
  50 NSPR_API(PRStatus) PR_CNotify(void *address);
  51
  52 /*
  53 ** Like PR_NotifyAll except use the "address" to find a monitor in the
  54 ** monitor cache.
  55 */
  56 NSPR_API(PRStatus) PR_CNotifyAll(void *address);
  57
  58 /*
  59 ** Set a callback to be invoked each time a monitor is recycled from the cache
  60 ** freelist, with the monitor's cache-key passed in address.
  61 */
  62 NSPR_API(void) PR_CSetOnMonitorRecycle(void (PR_CALLBACK *callback)(void *address));
  63
  64 PR_END_EXTERN_C
  65
  66 #endif /* prcmon_h___ */