WebSVN – HelenOS – Diff – /trunk/kernel/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.
 */
 
/** @addtogroup sync
 * @{
 */
 
/**
 * @file
 * @brief   Condition variables.
 */
 
#include <synch/condvar.h>
#include <synch/mutex.h>
#include <synch/waitq.h>
#include <synch/synch.h>
#include <arch.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.
 * @param flags     Select mode of operation.
 *
 * For exact description of meaning of possible combinations of usec and flags,
 * see comment for waitq_sleep_timeout().  Note that when
 * SYNCH_FLAGS_NON_BLOCKING is specified here, ESYNCH_WOULD_BLOCK is always
 * returned.
 *
 * @return      See comment for waitq_sleep_timeout().
 */
int _condvar_wait_timeout(condvar_t *cv, mutex_t *mtx, uint32_t usec, int flags)
{
    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, flags);
 
    mutex_lock(mtx);
    waitq_sleep_finish(&cv->wq, rc, ipl);
 
    return rc;
}
 
/** @}
 */
 

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/synch/condvar.c @ 2071 – Rev 2089 → 3186

Rev 2089		Rev 3186
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	/** @addtogroup sync	29	/** @addtogroup sync
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file	34	* @file
35	* @brief Condition variables.	35	* @brief Condition variables.
36	*/	36	*/
37		37
38	#include <synch/condvar.h>	38	#include <synch/condvar.h>
39	#include <synch/mutex.h>	39	#include <synch/mutex.h>
40	#include <synch/waitq.h>	40	#include <synch/waitq.h>
41	#include <synch/synch.h>	41	#include <synch/synch.h>
42	#include <arch.h>	42	#include <arch.h>
43		43
44	/** Initialize condition variable.	44	/** Initialize condition variable.
45	*	45	*
46	* @param cv Condition variable.	46	* @param cv Condition variable.
47	*/	47	*/
48	void condvar_initialize(condvar_t *cv)	48	void condvar_initialize(condvar_t *cv)
49	{	49	{
50	waitq_initialize(&cv->wq);	50	waitq_initialize(&cv->wq);
51	}	51	}
52		52
53	/**	-
54	* Signal the condition has become true	53	/** Signal the condition has become true to the first waiting thread by waking
55	* to the first waiting thread by waking it up.	54	* it up.
56	*	55	*
57	* @param cv Condition variable.	56	* @param cv Condition variable.
58	*/	57	*/
59	void condvar_signal(condvar_t *cv)	58	void condvar_signal(condvar_t *cv)
60	{	59	{
61	waitq_wakeup(&cv->wq, WAKEUP_FIRST);	60	waitq_wakeup(&cv->wq, WAKEUP_FIRST);
62	}	61	}
63		62
64	/**	-
65	* Signal the condition has become true	63	/** Signal the condition has become true to all waiting threads by waking
66	* to all waiting threads by waking them up.	64	* them up.
67	*	65	*
68	* @param cv Condition variable.	66	* @param cv Condition variable.
69	*/	67	*/
70	void condvar_broadcast(condvar_t *cv)	68	void condvar_broadcast(condvar_t *cv)
71	{	69	{
72	waitq_wakeup(&cv->wq, WAKEUP_ALL);	70	waitq_wakeup(&cv->wq, WAKEUP_ALL);
73	}	71	}
74		72
75	/** Wait for the condition becoming true.	73	/** Wait for the condition becoming true.
76	*	74	*
77	* @param cv Condition variable.	75	* @param cv Condition variable.
78	* @param mtx Mutex.	76	* @param mtx Mutex.
79	* @param usec Timeout value in microseconds.	77	* @param usec Timeout value in microseconds.
80	* @param flags Select mode of operation.	78	* @param flags Select mode of operation.
81	*	79	*
82	* For exact description of meaning of possible combinations	80	* For exact description of meaning of possible combinations of usec and flags,
83	* of usec and flags, see comment for waitq_sleep_timeout().	81	* see comment for waitq_sleep_timeout(). Note that when
84	* Note that when SYNCH_FLAGS_NON_BLOCKING is specified here,	82	* SYNCH_FLAGS_NON_BLOCKING is specified here, ESYNCH_WOULD_BLOCK is always
85	* ESYNCH_WOULD_BLOCK is always returned.	83	* returned.
86	*	84	*
87	* @return See comment for waitq_sleep_timeout().	85	* @return See comment for waitq_sleep_timeout().
88	*/	86	*/
89	int _condvar_wait_timeout(condvar_t cv, mutex_t mtx, uint32_t usec, int flags)	87	int _condvar_wait_timeout(condvar_t cv, mutex_t mtx, uint32_t usec, int flags)
90	{	88	{
91	int rc;	89	int rc;
92	ipl_t ipl;	90	ipl_t ipl;
93		91
94	ipl = waitq_sleep_prepare(&cv->wq);	92	ipl = waitq_sleep_prepare(&cv->wq);
95	mutex_unlock(mtx);	93	mutex_unlock(mtx);
96		94
97	cv->wq.missed_wakeups = 0; /* Enforce blocking. */	95	cv->wq.missed_wakeups = 0; /* Enforce blocking. */
98	rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags);	96	rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags);
99		97
100	mutex_lock(mtx);	98	mutex_lock(mtx);
101	waitq_sleep_finish(&cv->wq, rc, ipl);	99	waitq_sleep_finish(&cv->wq, rc, ipl);
102		100
103	return rc;	101	return rc;
104	}	102	}
105		103
106	/** @}	104	/** @}
107	*/	105	*/
108		106