1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* 3 * The contents of this file are subject to the Mozilla Public 4 * License Version 1.1 (the "License"); you may not use this file 5 * except in compliance with the License. You may obtain a copy of 6 * the License at http://www.mozilla.org/MPL/ 7 * 8 * Software distributed under the License is distributed on an "AS 9 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or 10 * implied. See the License for the specific language governing 11 * rights and limitations under the License. 12 * 13 * The Original Code is the Netscape Portable Runtime (NSPR). 14 * 15 * The Initial Developer of the Original Code is Netscape 16 * Communications Corporation. Portions created by Netscape are 17 * Copyright (C) 1998-2000 Netscape Communications Corporation. All 18 * Rights Reserved. 19 * 20 * Contributor(s): 21 * 22 * Alternatively, the contents of this file may be used under the 23 * terms of the GNU General Public License Version 2 or later (the 24 * "GPL"), in which case the provisions of the GPL are applicable 25 * instead of those above. If you wish to allow use of your 26 * version of this file only under the terms of the GPL and not to 27 * allow others to use your version of this file under the MPL, 28 * indicate your decision by deleting the provisions above and 29 * replace them with the notice and other provisions required by 30 * the GPL. If you do not delete the provisions above, a recipient 31 * may use your version of this file under either the MPL or the 32 * GPL. 33 */ 34 35 #ifndef prmon_h___ 36 #define prmon_h___ 37 38 #include "prtypes.h" 39 #include "prinrval.h" 40 41 PR_BEGIN_EXTERN_C 42 43 typedef struct PRMonitor PRMonitor; 44 45 /* 46 ** Create a new monitor. Monitors are re-entrant locks with a single built-in 47 ** condition variable. 48 ** 49 ** This may fail if memory is tight or if some operating system resource 50 ** is low. 51 */ 52 NSPR_API(PRMonitor*) PR_NewMonitor(void); 53 54 /* 55 ** Destroy a monitor. The caller is responsible for guaranteeing that the 56 ** monitor is no longer in use. There must be no thread waiting on the monitor's 57 ** condition variable and that the lock is not held. 58 ** 59 */ 60 NSPR_API(void) PR_DestroyMonitor(PRMonitor *mon); 61 62 /* 63 ** Enter the lock associated with the monitor. If the calling thread currently 64 ** is in the monitor, the call to enter will silently succeed. In either case, 65 ** it will increment the entry count by one. 66 */ 67 NSPR_API(void) PR_EnterMonitor(PRMonitor *mon); 68 69 /* 70 ** Decrement the entry count associated with the monitor. If the decremented 71 ** entry count is zero, the monitor is exited. Returns PR_FAILURE if the 72 ** calling thread has not entered the monitor. 73 */ 74 NSPR_API(PRStatus) PR_ExitMonitor(PRMonitor *mon); 75 76 /* 77 ** Wait for a notify on the monitor's condition variable. Sleep for "ticks" 78 ** amount of time (if "ticks" is PR_INTERVAL_NO_TIMEOUT then the sleep is 79 ** indefinite). 80 ** 81 ** While the thread is waiting it exits the monitor (as if it called 82 ** PR_ExitMonitor as many times as it had called PR_EnterMonitor). When 83 ** the wait has finished the thread regains control of the monitors lock 84 ** with the same entry count as before the wait began. 85 ** 86 ** The thread waiting on the monitor will be resumed when the monitor is 87 ** notified (assuming the thread is the next in line to receive the 88 ** notify) or when the "ticks" timeout elapses. 89 ** 90 ** Returns PR_FAILURE if the caller has not entered the monitor. 91 */ 92 NSPR_API(PRStatus) PR_Wait(PRMonitor *mon, PRIntervalTime ticks); 93 94 /* 95 ** Notify a thread waiting on the monitor's condition variable. If a thread 96 ** is waiting on the condition variable (using PR_Wait) then it is awakened 97 ** and attempts to reenter the monitor. 98 */ 99 NSPR_API(PRStatus) PR_Notify(PRMonitor *mon); 100 101 /* 102 ** Notify all of the threads waiting on the monitor's condition variable. 103 ** All of threads waiting on the condition are scheduled to reenter the 104 ** monitor. 105 */ 106 NSPR_API(PRStatus) PR_NotifyAll(PRMonitor *mon); 107 108 PR_END_EXTERN_C 109 110 #endif /* prmon_h___ */ 111
