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
 
 * @{
 */
 
/**
 * @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 1702 → 1705

Rev 1702		Rev 1705
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	29	/** @addtogroup sync
30	* @ingroup kernel	-
31	* @{	30	* @{
32	*/	31	*/
33		32
34	/**	33	/**
35	* @file	34	* @file
36	* @brief Condition variables.	35	* @brief Condition variables.
37	*/	36	*/
38		37
39	#include <synch/condvar.h>	38	#include <synch/condvar.h>
40	#include <synch/mutex.h>	39	#include <synch/mutex.h>
41	#include <synch/waitq.h>	40	#include <synch/waitq.h>
42	#include <synch/synch.h>	41	#include <synch/synch.h>
43	#include <arch.h>	42	#include <arch.h>
44	#include <typedefs.h>	43	#include <typedefs.h>
45		44
46	/** Initialize condition variable.	45	/** Initialize condition variable.
47	*	46	*
48	* @param cv Condition variable.	47	* @param cv Condition variable.
49	*/	48	*/
50	void condvar_initialize(condvar_t *cv)	49	void condvar_initialize(condvar_t *cv)
51	{	50	{
52	waitq_initialize(&cv->wq);	51	waitq_initialize(&cv->wq);
53	}	52	}
54		53
55	/**	54	/**
56	* Signal the condition has become true	55	* Signal the condition has become true
57	* to the first waiting thread by waking it up.	56	* to the first waiting thread by waking it up.
58	*	57	*
59	* @param cv Condition variable.	58	* @param cv Condition variable.
60	*/	59	*/
61	void condvar_signal(condvar_t *cv)	60	void condvar_signal(condvar_t *cv)
62	{	61	{
63	waitq_wakeup(&cv->wq, WAKEUP_FIRST);	62	waitq_wakeup(&cv->wq, WAKEUP_FIRST);
64	}	63	}
65		64
66	/**	65	/**
67	* Signal the condition has become true	66	* Signal the condition has become true
68	* to all waiting threads by waking them up.	67	* to all waiting threads by waking them up.
69	*	68	*
70	* @param cv Condition variable.	69	* @param cv Condition variable.
71	*/	70	*/
72	void condvar_broadcast(condvar_t *cv)	71	void condvar_broadcast(condvar_t *cv)
73	{	72	{
74	waitq_wakeup(&cv->wq, WAKEUP_ALL);	73	waitq_wakeup(&cv->wq, WAKEUP_ALL);
75	}	74	}
76		75
77	/** Wait for the condition becoming true.	76	/** Wait for the condition becoming true.
78	*	77	*
79	* @param cv Condition variable.	78	* @param cv Condition variable.
80	* @param mtx Mutex.	79	* @param mtx Mutex.
81	* @param usec Timeout value in microseconds.	80	* @param usec Timeout value in microseconds.
82	* @param flags Select mode of operation.	81	* @param flags Select mode of operation.
83	*	82	*
84	* For exact description of meaning of possible combinations	83	* For exact description of meaning of possible combinations
85	* of usec and flags, see comment for waitq_sleep_timeout().	84	* of usec and flags, see comment for waitq_sleep_timeout().
86	* Note that when SYNCH_FLAGS_NON_BLOCKING is specified here,	85	* Note that when SYNCH_FLAGS_NON_BLOCKING is specified here,
87	* ESYNCH_WOULD_BLOCK is always returned.	86	* ESYNCH_WOULD_BLOCK is always returned.
88	*	87	*
89	* @return See comment for waitq_sleep_timeout().	88	* @return See comment for waitq_sleep_timeout().
90	*/	89	*/
91	int _condvar_wait_timeout(condvar_t cv, mutex_t mtx, __u32 usec, int flags)	90	int _condvar_wait_timeout(condvar_t cv, mutex_t mtx, __u32 usec, int flags)
92	{	91	{
93	int rc;	92	int rc;
94	ipl_t ipl;	93	ipl_t ipl;
95		94
96	ipl = waitq_sleep_prepare(&cv->wq);	95	ipl = waitq_sleep_prepare(&cv->wq);
97	mutex_unlock(mtx);	96	mutex_unlock(mtx);
98		97
99	cv->wq.missed_wakeups = 0; /* Enforce blocking. */	98	cv->wq.missed_wakeups = 0; /* Enforce blocking. */
100	rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags);	99	rc = waitq_sleep_timeout_unsafe(&cv->wq, usec, flags);
101		100
102	mutex_lock(mtx);	101	mutex_lock(mtx);
103	waitq_sleep_finish(&cv->wq, rc, ipl);	102	waitq_sleep_finish(&cv->wq, rc, ipl);
104		103
105	return rc;	104	return rc;
106	}	105	}
107		106
108	/** @}	107	/** @}
109	*/	108	*/
110		109
111		110