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.
 */
 
 /** @addtogroup sync Synchronization
 * @ingroup kernel
 * @{
 */
 
/**
 * @file
 * @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.
 * @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, __u32 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-historic

(root)/kernel/trunk/generic/src/synch/condvar.c – Rev 1502 → 1702

Rev 1502		Rev 1702
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 Synchronization
-		30	* @ingroup kernel
-		31	* @{
-		32	*/
-		33
29	/**	34	/**
30	* @file condvar.c	35	* @file
31	* @brief Condition variables.	36	* @brief Condition variables.
32	*/	37	*/
33		38
34	#include <synch/condvar.h>	39	#include <synch/condvar.h>
35	#include <synch/mutex.h>	40	#include <synch/mutex.h>
36	#include <synch/waitq.h>	41	#include <synch/waitq.h>
37	#include <synch/synch.h>	42	#include <synch/synch.h>
38	#include <arch.h>	43	#include <arch.h>
39	#include <typedefs.h>	44	#include <typedefs.h>
40		45
41	/** Initialize condition variable.	46	/** Initialize condition variable.
42	*	47	*
43	* @param cv Condition variable.	48	* @param cv Condition variable.
44	*/	49	*/
45	void condvar_initialize(condvar_t *cv)	50	void condvar_initialize(condvar_t *cv)
46	{	51	{
47	waitq_initialize(&cv->wq);	52	waitq_initialize(&cv->wq);
48	}	53	}
49		54
50	/**	55	/**
51	* Signal the condition has become true	56	* Signal the condition has become true
52	* to the first waiting thread by waking it up.	57	* to the first waiting thread by waking it up.
53	*	58	*
54	* @param cv Condition variable.	59	* @param cv Condition variable.
55	*/	60	*/
56	void condvar_signal(condvar_t *cv)	61	void condvar_signal(condvar_t *cv)
57	{	62	{
58	waitq_wakeup(&cv->wq, WAKEUP_FIRST);	63	waitq_wakeup(&cv->wq, WAKEUP_FIRST);
59	}	64	}
60		65
61	/**	66	/**
62	* Signal the condition has become true	67	* Signal the condition has become true
63	* to all waiting threads by waking them up.	68	* to all waiting threads by waking them up.
64	*	69	*
65	* @param cv Condition variable.	70	* @param cv Condition variable.
66	*/	71	*/
67	void condvar_broadcast(condvar_t *cv)	72	void condvar_broadcast(condvar_t *cv)
68	{	73	{
69	waitq_wakeup(&cv->wq, WAKEUP_ALL);	74	waitq_wakeup(&cv->wq, WAKEUP_ALL);
70	}	75	}
71		76
72	/** Wait for the condition becoming true.	77	/** Wait for the condition becoming true.
73	*	78	*
74	* @param cv Condition variable.	79	* @param cv Condition variable.
75	* @param mtx Mutex.	80	* @param mtx Mutex.
76	* @param usec Timeout value in microseconds.	81	* @param usec Timeout value in microseconds.
77	* @param flags Select mode of operation.	82	* @param flags Select mode of operation.
78	*	83	*
79	* For exact description of meaning of possible combinations	84	* For exact description of meaning of possible combinations
80	* of usec and flags, see comment for waitq_sleep_timeout().	85	* of usec and flags, see comment for waitq_sleep_timeout().
81	* Note that when SYNCH_FLAGS_NON_BLOCKING is specified here,	86	* Note that when SYNCH_FLAGS_NON_BLOCKING is specified here,
82	* ESYNCH_WOULD_BLOCK is always returned.	87	* ESYNCH_WOULD_BLOCK is always returned.
83	*	88	*
84	* @return See comment for waitq_sleep_timeout().	89	* @return See comment for waitq_sleep_timeout().
85	*/	90	*/
86	int _condvar_wait_timeout(condvar_t cv, mutex_t mtx, __u32 usec, int flags)	91	int _condvar_wait_timeout(condvar_t cv, mutex_t mtx, __u32 usec, int flags)
87	{	92	{
88	int rc;	93	int rc;
89	ipl_t ipl;	94	ipl_t ipl;
90		95
91	ipl = waitq_sleep_prepare(&cv->wq);	96	ipl = waitq_sleep_prepare(&cv->wq);
92	mutex_unlock(mtx);	97	mutex_unlock(mtx);
93		98
94	cv->wq.missed_wakeups = 0; /* Enforce blocking. */	99	cv->wq.missed_wakeups = 0; /* Enforce blocking. */
95	rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags);	100	rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags);
96		101
97	mutex_lock(mtx);	102	mutex_lock(mtx);
98	waitq_sleep_finish(&cv->wq, rc, ipl);	103	waitq_sleep_finish(&cv->wq, rc, ipl);
99		104
100	return rc;	105	return rc;
101	}	106	}
-		107
-		108	/** @}
-		109	*/
-		110
102		111