libraries/source/spidermonkey/include-win32-debug/nspr/prmon.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 prmon_h___
   7 #define prmon_h___
   8
   9 #include "prtypes.h"
  10 #include "prinrval.h"
  11
  12 PR_BEGIN_EXTERN_C
  13
  14 typedef struct PRMonitor PRMonitor;
  15
  16 /*
  17 ** Create a new monitor. Monitors are re-entrant locks with a single built-in
  18 ** condition variable.
  19 **
  20 ** This may fail if memory is tight or if some operating system resource
  21 ** is low.
  22 */
  23 NSPR_API(PRMonitor*) PR_NewMonitor(void);
  24
  25 /*
  26 ** Destroy a monitor. The caller is responsible for guaranteeing that the
  27 ** monitor is no longer in use. There must be no thread waiting on the monitor's
  28 ** condition variable and that the lock is not held.
  29 **
  30 */
  31 NSPR_API(void) PR_DestroyMonitor(PRMonitor *mon);
  32
  33 /*
  34 ** Enter the lock associated with the monitor. If the calling thread currently
  35 ** is in the monitor, the call to enter will silently succeed. In either case,
  36 ** it will increment the entry count by one.
  37 */
  38 NSPR_API(void) PR_EnterMonitor(PRMonitor *mon);
  39
  40 /*
  41 ** Decrement the entry count associated with the monitor. If the decremented
  42 ** entry count is zero, the monitor is exited. Returns PR_FAILURE if the
  43 ** calling thread has not entered the monitor.
  44 */
  45 NSPR_API(PRStatus) PR_ExitMonitor(PRMonitor *mon);
  46
  47 /*
  48 ** Wait for a notify on the monitor's condition variable. Sleep for "ticks"
  49 ** amount of time (if "ticks" is PR_INTERVAL_NO_TIMEOUT then the sleep is
  50 ** indefinite).
  51 **
  52 ** While the thread is waiting it exits the monitor (as if it called
  53 ** PR_ExitMonitor as many times as it had called PR_EnterMonitor).  When
  54 ** the wait has finished the thread regains control of the monitors lock
  55 ** with the same entry count as before the wait began.
  56 **
  57 ** The thread waiting on the monitor will be resumed when the monitor is
  58 ** notified (assuming the thread is the next in line to receive the
  59 ** notify) or when the "ticks" timeout elapses.
  60 **
  61 ** Returns PR_FAILURE if the caller has not entered the monitor.
  62 */
  63 NSPR_API(PRStatus) PR_Wait(PRMonitor *mon, PRIntervalTime ticks);
  64
  65 /*
  66 ** Notify a thread waiting on the monitor's condition variable. If a thread
  67 ** is waiting on the condition variable (using PR_Wait) then it is awakened
  68 ** and attempts to reenter the monitor.
  69 */
  70 NSPR_API(PRStatus) PR_Notify(PRMonitor *mon);
  71
  72 /*
  73 ** Notify all of the threads waiting on the monitor's condition variable.
  74 ** All of threads waiting on the condition are scheduled to reenter the
  75 ** monitor.
  76 */
  77 NSPR_API(PRStatus) PR_NotifyAll(PRMonitor *mon);
  78
  79 /*
  80 ** PR_ASSERT_CURRENT_THREAD_IN_MONITOR
  81 ** If the current thread is in |mon|, this assertion is guaranteed to
  82 ** succeed.  Otherwise, the behavior of this function is undefined.
  83 */
  84 #if defined(DEBUG) || defined(FORCE_PR_ASSERT)
  85 #define PR_ASSERT_CURRENT_THREAD_IN_MONITOR(/* PRMonitor* */ mon) \
  86     PR_AssertCurrentThreadInMonitor(mon)
  87 #else
  88 #define PR_ASSERT_CURRENT_THREAD_IN_MONITOR(/* PRMonitor* */ mon)
  89 #endif
  90
  91 /* Don't call this function directly. */
  92 NSPR_API(void) PR_AssertCurrentThreadInMonitor(PRMonitor *mon);
  93
  94 PR_END_EXTERN_C
  95
  96 #endif /* prmon_h___ */