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       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         393 : 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        8809 : 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        9064 : 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        9064 : 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          56 : 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          56 : 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           0 : 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        6741 : NSPR_API(void) PR_AssertCurrentThreadInMonitor(PRMonitor *mon);
      93             : 
      94             : PR_END_EXTERN_C
      95             : 
      96             : #endif /* prmon_h___ */