source: mainline/kernel/generic/src/synch/condvar.c@ 8ccd2ea

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 8ccd2ea was b3f8fb7, checked in by Martin Decky <martin@…>, 18 years ago

huge type system cleanup
remove cyclical type dependencies across multiple header files
many minor coding style fixes

  • Property mode set to 100644
File size: 3.0 KB
RevLine 
[f761f1eb]1/*
[df4ed85]2 * Copyright (c) 2001-2004 Jakub Jermar
[f761f1eb]3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
[cc73a8a1]29/** @addtogroup sync
[b45c443]30 * @{
31 */
32
[cf26ba9]33/**
[b45c443]34 * @file
[cf26ba9]35 * @brief Condition variables.
36 */
37
[f761f1eb]38#include <synch/condvar.h>
39#include <synch/mutex.h>
40#include <synch/waitq.h>
[df364582]41#include <synch/synch.h>
[c0bc189]42#include <arch.h>
[f761f1eb]43
[c0bc189]44/** Initialize condition variable.
[df364582]45 *
46 * @param cv Condition variable.
47 */
[f761f1eb]48void condvar_initialize(condvar_t *cv)
49{
50 waitq_initialize(&cv->wq);
51}
52
[c0bc189]53/**
[df364582]54 * Signal the condition has become true
55 * to the first waiting thread by waking it up.
56 *
[a783ca4]57 * @param cv Condition variable.
[df364582]58 */
[f761f1eb]59void condvar_signal(condvar_t *cv)
60{
61 waitq_wakeup(&cv->wq, WAKEUP_FIRST);
62}
63
[c0bc189]64/**
[df364582]65 * Signal the condition has become true
66 * to all waiting threads by waking them up.
67 *
[a783ca4]68 * @param cv Condition variable.
[df364582]69 */
[f761f1eb]70void condvar_broadcast(condvar_t *cv)
71{
72 waitq_wakeup(&cv->wq, WAKEUP_ALL);
73}
74
[c0bc189]75/** Wait for the condition becoming true.
[df364582]76 *
[a783ca4]77 * @param cv Condition variable.
78 * @param mtx Mutex.
79 * @param usec Timeout value in microseconds.
[116d1ef4]80 * @param flags Select mode of operation.
[a783ca4]81 *
[116d1ef4]82 * For exact description of meaning of possible combinations
83 * of usec and flags, see comment for waitq_sleep_timeout().
84 * Note that when SYNCH_FLAGS_NON_BLOCKING is specified here,
85 * ESYNCH_WOULD_BLOCK is always returned.
[a783ca4]86 *
87 * @return See comment for waitq_sleep_timeout().
[df364582]88 */
[7f1c620]89int _condvar_wait_timeout(condvar_t *cv, mutex_t *mtx, uint32_t usec, int flags)
[f761f1eb]90{
91 int rc;
[c0bc189]92 ipl_t ipl;
[f761f1eb]93
[c0bc189]94 ipl = waitq_sleep_prepare(&cv->wq);
[f761f1eb]95 mutex_unlock(mtx);
[baafe71]96
97 cv->wq.missed_wakeups = 0; /* Enforce blocking. */
[116d1ef4]98 rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags);
[c0bc189]99
[f761f1eb]100 mutex_lock(mtx);
[c0bc189]101 waitq_sleep_finish(&cv->wq, rc, ipl);
102
[f761f1eb]103 return rc;
104}
[b45c443]105
[cc73a8a1]106/** @}
[b45c443]107 */
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