WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/synch/semaphore.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   Semaphores.
 */
 
#include <synch/semaphore.h>
#include <synch/waitq.h>
#include <synch/spinlock.h>
#include <synch/synch.h>
#include <arch/asm.h>
#include <arch.h>
 
/** Initialize semaphore
 *
 * Initialize semaphore.
 *
 * @param s Semaphore.
 * @param val Maximal number of threads allowed to enter critical section.
 */
void semaphore_initialize(semaphore_t *s, int val)
{
    ipl_t ipl;
   
    waitq_initialize(&s->wq);
   
    ipl = interrupts_disable();
 
    spinlock_lock(&s->wq.lock);
    s->wq.missed_wakeups = val;
    spinlock_unlock(&s->wq.lock);
 
    interrupts_restore(ipl);
}
 
/** Semaphore down
 *
 * Semaphore down.
 * Conditional mode and mode with timeout can be requested.
 *
 * @param s Semaphore.
 * @param usec Timeout in microseconds.
 * @param flags Select mode of operation.
 *
 * For exact description of possible combinations of
 * usec and flags, see comment for waitq_sleep_timeout().
 *
 * @return See comment for waitq_sleep_timeout().
 */
int _semaphore_down_timeout(semaphore_t *s, __u32 usec, int flags)
{
    return waitq_sleep_timeout(&s->wq, usec, flags);
}
 
/** Semaphore up
 *
 * Semaphore up.
 *
 * @param s Semaphore.
 */
void semaphore_up(semaphore_t *s)
{
    waitq_wakeup(&s->wq, WAKEUP_FIRST);
}
 
/** @}
 */
 
 

Rev 1702	Rev 1757
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 Semaphores.	35	* @brief Semaphores.
36	*/	36	*/
37		37
38	#include <synch/semaphore.h>	38	#include <synch/semaphore.h>
39	#include <synch/waitq.h>	39	#include <synch/waitq.h>
40	#include <synch/spinlock.h>	40	#include <synch/spinlock.h>
41	#include <synch/synch.h>	41	#include <synch/synch.h>
42	#include <arch/asm.h>	42	#include <arch/asm.h>
43	#include <arch.h>	43	#include <arch.h>
44		44
45	/** Initialize semaphore	45	/** Initialize semaphore
46	*	46	*
47	* Initialize semaphore.	47	* Initialize semaphore.
48	*	48	*
49	* @param s Semaphore.	49	* @param s Semaphore.
50	* @param val Maximal number of threads allowed to enter critical section.	50	* @param val Maximal number of threads allowed to enter critical section.
51	*/	51	*/
52	void semaphore_initialize(semaphore_t *s, int val)	52	void semaphore_initialize(semaphore_t *s, int val)
53	{	53	{
54	ipl_t ipl;	54	ipl_t ipl;
55		55
56	waitq_initialize(&s->wq);	56	waitq_initialize(&s->wq);
57		57
58	ipl = interrupts_disable();	58	ipl = interrupts_disable();
59		59
60	spinlock_lock(&s->wq.lock);	60	spinlock_lock(&s->wq.lock);
61	s->wq.missed_wakeups = val;	61	s->wq.missed_wakeups = val;
62	spinlock_unlock(&s->wq.lock);	62	spinlock_unlock(&s->wq.lock);
63		63
64	interrupts_restore(ipl);	64	interrupts_restore(ipl);
65	}	65	}
66		66
67	/** Semaphore down	67	/** Semaphore down
68	*	68	*
69	* Semaphore down.	69	* Semaphore down.
70	* Conditional mode and mode with timeout can be requested.	70	* Conditional mode and mode with timeout can be requested.
71	*	71	*
72	* @param s Semaphore.	72	* @param s Semaphore.
73	* @param usec Timeout in microseconds.	73	* @param usec Timeout in microseconds.
74	* @param flags Select mode of operation.	74	* @param flags Select mode of operation.
75	*	75	*
76	* For exact description of possible combinations of	76	* For exact description of possible combinations of
77	* usec and flags, see comment for waitq_sleep_timeout().	77	* usec and flags, see comment for waitq_sleep_timeout().
78	*	78	*
79	* @return See comment for waitq_sleep_timeout().	79	* @return See comment for waitq_sleep_timeout().
80	*/	80	*/
81	int _semaphore_down_timeout(semaphore_t *s, __u32 usec, int flags)	81	int _semaphore_down_timeout(semaphore_t *s, __u32 usec, int flags)
82	{	82	{
83	return waitq_sleep_timeout(&s->wq, usec, flags);	83	return waitq_sleep_timeout(&s->wq, usec, flags);
84	}	84	}
85		85
86	/** Semaphore up	86	/** Semaphore up
87	*	87	*
88	* Semaphore up.	88	* Semaphore up.
89	*	89	*
90	* @param s Semaphore.	90	* @param s Semaphore.
91	*/	91	*/
92	void semaphore_up(semaphore_t *s)	92	void semaphore_up(semaphore_t *s)
93	{	93	{
94	waitq_wakeup(&s->wq, WAKEUP_FIRST);	94	waitq_wakeup(&s->wq, WAKEUP_FIRST);
95	}	95	}
96		96
97	/** @}	97	/** @}
98	*/	98	*/
99		-
100		99

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/synch/semaphore.c – Rev 1702 → 1757