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
12PR_BEGIN_EXTERN_C
13
14typedef 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*/
23NSPR_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*/
31NSPR_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*/
38NSPR_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*/
45NSPR_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*/
63NSPR_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*/
70NSPR_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*/
77NSPR_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. */
92NSPR_API(void) PR_AssertCurrentThreadInMonitor(PRMonitor *mon);
93
94PR_END_EXTERN_C
95
96#endif /* prmon_h___ */
97

source code of include/nspr/prmon.h