WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/synch/condvar.c


/*
 * Copyright (C) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/**
 * @file    condvar.c
 * @brief   Condition variables.
 */
 
#include <synch/condvar.h>
#include <synch/mutex.h>
#include <synch/waitq.h>
#include <synch/synch.h>
#include <arch.h>
#include <typedefs.h>
 
/** Initialize condition variable.
 *
 * @param cv Condition variable.
 */
void condvar_initialize(condvar_t *cv)
{
    waitq_initialize(&cv->wq);
}
 
/**
 * Signal the condition has become true
 * to the first waiting thread by waking it up.
 *
 * @param cv Condition variable.
 */
void condvar_signal(condvar_t *cv)
{
    waitq_wakeup(&cv->wq, WAKEUP_FIRST);
}
 
/**
 * Signal the condition has become true
 * to all waiting threads by waking them up.
 *
 * @param cv Condition variable.
 */
void condvar_broadcast(condvar_t *cv)
{
    waitq_wakeup(&cv->wq, WAKEUP_ALL);
}
 
/** Wait for the condition becoming true.
 *
 * @param cv Condition variable.
 * @param mtx Mutex.
 * @param usec Timeout value in microseconds.
 
 *
 * For exact description of meaning of possible values of usec,
 * see comment for waitq_sleep_timeout().
 *
 * @return See comment for waitq_sleep_timeout().
 */
int _condvar_wait_timeout(condvar_t *cv, mutex_t *mtx, __u32 usec)
{
    int rc;
    ipl_t ipl;
 
    ipl = waitq_sleep_prepare(&cv->wq);
    mutex_unlock(mtx);
 
    cv->wq.missed_wakeups = 0;  /* Enforce blocking. */
    rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, SYNCH_BLOCKING);
 
    mutex_lock(mtx);
    waitq_sleep_finish(&cv->wq, rc, ipl);
 
    return rc;
}
 

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/synch/condvar.c – Rev 1375 → 1416

Rev 1375		Rev 1416
1	/*	1	/*
2	* Copyright (C) 2001-2004 Jakub Jermar	2	* Copyright (C) 2001-2004 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	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	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.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	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	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	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	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	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	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.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/**	29	/**
30	* @file condvar.c	30	* @file condvar.c
31	* @brief Condition variables.	31	* @brief Condition variables.
32	*/	32	*/
33		33
34	#include <synch/condvar.h>	34	#include <synch/condvar.h>
35	#include <synch/mutex.h>	35	#include <synch/mutex.h>
36	#include <synch/waitq.h>	36	#include <synch/waitq.h>
37	#include <synch/synch.h>	37	#include <synch/synch.h>
38	#include <arch.h>	38	#include <arch.h>
39	#include <typedefs.h>	39	#include <typedefs.h>
40		40
41	/** Initialize condition variable.	41	/** Initialize condition variable.
42	*	42	*
43	* @param cv Condition variable.	43	* @param cv Condition variable.
44	*/	44	*/
45	void condvar_initialize(condvar_t *cv)	45	void condvar_initialize(condvar_t *cv)
46	{	46	{
47	waitq_initialize(&cv->wq);	47	waitq_initialize(&cv->wq);
48	}	48	}
49		49
50	/**	50	/**
51	* Signal the condition has become true	51	* Signal the condition has become true
52	* to the first waiting thread by waking it up.	52	* to the first waiting thread by waking it up.
53	*	53	*
54	* @param cv Condition variable.	54	* @param cv Condition variable.
55	*/	55	*/
56	void condvar_signal(condvar_t *cv)	56	void condvar_signal(condvar_t *cv)
57	{	57	{
58	waitq_wakeup(&cv->wq, WAKEUP_FIRST);	58	waitq_wakeup(&cv->wq, WAKEUP_FIRST);
59	}	59	}
60		60
61	/**	61	/**
62	* Signal the condition has become true	62	* Signal the condition has become true
63	* to all waiting threads by waking them up.	63	* to all waiting threads by waking them up.
64	*	64	*
65	* @param cv Condition variable.	65	* @param cv Condition variable.
66	*/	66	*/
67	void condvar_broadcast(condvar_t *cv)	67	void condvar_broadcast(condvar_t *cv)
68	{	68	{
69	waitq_wakeup(&cv->wq, WAKEUP_ALL);	69	waitq_wakeup(&cv->wq, WAKEUP_ALL);
70	}	70	}
71		71
72	/** Wait for the condition becoming true.	72	/** Wait for the condition becoming true.
73	*	73	*
74	* @param cv Condition variable.	74	* @param cv Condition variable.
75	* @param mtx Mutex.	75	* @param mtx Mutex.
76	* @param usec Timeout value in microseconds.	76	* @param usec Timeout value in microseconds.
77	* @param trywait Blocking versus non-blocking operation mode switch.	-
78	*	77	*
79	* For exact description of possible combinations of	78	* For exact description of meaning of possible values of usec,
80	* usec and trywait, see comment for waitq_sleep_timeout().	79	* see comment for waitq_sleep_timeout().
81	*	80	*
82	* @return See comment for waitq_sleep_timeout().	81	* @return See comment for waitq_sleep_timeout().
83	*/	82	*/
84	int _condvar_wait_timeout(condvar_t cv, mutex_t mtx, __u32 usec, int trywait)	83	int _condvar_wait_timeout(condvar_t cv, mutex_t mtx, __u32 usec)
85	{	84	{
86	int rc;	85	int rc;
87	ipl_t ipl;	86	ipl_t ipl;
88		87
89	ipl = waitq_sleep_prepare(&cv->wq);	88	ipl = waitq_sleep_prepare(&cv->wq);
90	mutex_unlock(mtx);	89	mutex_unlock(mtx);
91		90
-		91	cv->wq.missed_wakeups = 0; /* Enforce blocking. */
92	rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, trywait);	92	rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, SYNCH_BLOCKING);
93		93
94	mutex_lock(mtx);	94	mutex_lock(mtx);
95	waitq_sleep_finish(&cv->wq, rc, ipl);	95	waitq_sleep_finish(&cv->wq, rc, ipl);
96		96
97	return rc;	97	return rc;
98	}	98	}
99		99