Subversion Repositories HelenOS-historic

Rev

Rev 1705 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
1 jermar 1
/*
2
 * Copyright (C) 2001-2004 Jakub Jermar
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
 
1757 jermar 29
/** @addtogroup sync
1702 cejka 30
 * @{
31
 */
32
 
1264 jermar 33
/**
1702 cejka 34
 * @file
1264 jermar 35
 * @brief   Condition variables.
36
 */
37
 
1 jermar 38
#include <synch/condvar.h>
39
#include <synch/mutex.h>
40
#include <synch/waitq.h>
387 jermar 41
#include <synch/synch.h>
1375 jermar 42
#include <arch.h>
43
#include <typedefs.h>
1 jermar 44
 
1375 jermar 45
/** Initialize condition variable.
387 jermar 46
 *
47
 * @param cv Condition variable.
48
 */
1 jermar 49
void condvar_initialize(condvar_t *cv)
50
{
51
    waitq_initialize(&cv->wq);
52
}
53
 
1375 jermar 54
/**
387 jermar 55
 * Signal the condition has become true
56
 * to the first waiting thread by waking it up.
57
 *
404 jermar 58
 * @param cv Condition variable.
387 jermar 59
 */
1 jermar 60
void condvar_signal(condvar_t *cv)
61
{
62
    waitq_wakeup(&cv->wq, WAKEUP_FIRST);
63
}
64
 
1375 jermar 65
/**
387 jermar 66
 * Signal the condition has become true
67
 * to all waiting threads by waking them up.
68
 *
404 jermar 69
 * @param cv Condition variable.
387 jermar 70
 */
1 jermar 71
void condvar_broadcast(condvar_t *cv)
72
{
73
    waitq_wakeup(&cv->wq, WAKEUP_ALL);
74
}
75
 
1375 jermar 76
/** Wait for the condition becoming true.
387 jermar 77
 *
404 jermar 78
 * @param cv Condition variable.
79
 * @param mtx Mutex.
80
 * @param usec Timeout value in microseconds.
1502 jermar 81
 * @param flags Select mode of operation.
404 jermar 82
 *
1502 jermar 83
 * For exact description of meaning of possible combinations
84
 * of usec and flags, see comment for waitq_sleep_timeout().
85
 * Note that when SYNCH_FLAGS_NON_BLOCKING is specified here,
86
 * ESYNCH_WOULD_BLOCK is always returned.
404 jermar 87
 *
88
 * @return See comment for waitq_sleep_timeout().
387 jermar 89
 */
1502 jermar 90
int _condvar_wait_timeout(condvar_t *cv, mutex_t *mtx, __u32 usec, int flags)
1 jermar 91
{
92
    int rc;
1375 jermar 93
    ipl_t ipl;
1 jermar 94
 
1375 jermar 95
    ipl = waitq_sleep_prepare(&cv->wq);
1 jermar 96
    mutex_unlock(mtx);
1375 jermar 97
 
1416 jermar 98
    cv->wq.missed_wakeups = 0;  /* Enforce blocking. */
1502 jermar 99
    rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags);
1416 jermar 100
 
1 jermar 101
    mutex_lock(mtx);
1375 jermar 102
    waitq_sleep_finish(&cv->wq, rc, ipl);
103
 
1 jermar 104
    return rc;
105
}
1702 cejka 106
 
1757 jermar 107
/** @}
1702 cejka 108
 */