WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/synch/spinlock.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    spinlock.c
 * @brief   Spinlocks.
 */
 
#include <synch/spinlock.h>
#include <atomic.h>
#include <arch/barrier.h>
#include <arch.h>
#include <preemption.h>
#include <print.h>
#include <debug.h>
#include <symtab.h>
 
#ifdef CONFIG_SMP
 
/** Initialize spinlock
 *
 * Initialize spinlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
void spinlock_initialize(spinlock_t *sl, char *name)
{
    atomic_set(&sl->val, 0);
#ifdef CONFIG_DEBUG_SPINLOCK
    sl->name = name;
#endif  
}
 
/** Lock spinlock
 *
 * Lock spinlock.
 * This version has limitted ability to report
 * possible occurence of deadlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
#ifdef CONFIG_DEBUG_SPINLOCK
void spinlock_lock_debug(spinlock_t *sl)
{
    count_t i = 0;
    char *symbol;
    bool deadlock_reported = false;
 
    preemption_disable();
    while (test_and_set(&sl->val)) {
        if (i++ > 300000 && sl!=&printflock) {
            printf("cpu%d: looping on spinlock %.*p:%s, caller=%.*p",
                   CPU->id, sizeof(__address) * 2, sl, sl->name, sizeof(__address) * 2, CALLER);
            symbol = get_symtab_entry(CALLER);
            if (symbol)
                printf("(%s)", symbol);
            printf("\n");
            i = 0;
            deadlock_reported = true;
        }
    }
 
    if (deadlock_reported)
        printf("cpu%d: not deadlocked\n", CPU->id);
 
    /*
     * Prevent critical section code from bleeding out this way up.
     */
    CS_ENTER_BARRIER();
}
#endif
 
/** Lock spinlock conditionally
 *
 * Lock spinlock conditionally.
 * If the spinlock is not available at the moment,
 * signal failure.
 *
 * @param sl Pointer to spinlock_t structure.
 *
 * @return Zero on failure, non-zero otherwise.
 */
int spinlock_trylock(spinlock_t *sl)
{
    int rc;
   
    preemption_disable();
    rc = !test_and_set(&sl->val);
 
    /*
     * Prevent critical section code from bleeding out this way up.
     */
    CS_ENTER_BARRIER();
 
    if (!rc)
        preemption_enable();
   
    return rc;
}
 
#endif
 

Rev 1224	Rev 1264
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	/**
-		30	* @file spinlock.c
-		31	* @brief Spinlocks.
-		32	*/
-		33
29	#include <synch/spinlock.h>	34	#include <synch/spinlock.h>
30	#include <atomic.h>	35	#include <atomic.h>
31	#include <arch/barrier.h>	36	#include <arch/barrier.h>
32	#include <arch.h>	37	#include <arch.h>
33	#include <preemption.h>	38	#include <preemption.h>
34	#include <print.h>	39	#include <print.h>
35	#include <debug.h>	40	#include <debug.h>
36	#include <symtab.h>	41	#include <symtab.h>
37		42
38	#ifdef CONFIG_SMP	43	#ifdef CONFIG_SMP
39		44
40	/** Initialize spinlock	45	/** Initialize spinlock
41	*	46	*
42	* Initialize spinlock.	47	* Initialize spinlock.
43	*	48	*
44	* @param sl Pointer to spinlock_t structure.	49	* @param sl Pointer to spinlock_t structure.
45	*/	50	*/
46	void spinlock_initialize(spinlock_t sl, char name)	51	void spinlock_initialize(spinlock_t sl, char name)
47	{	52	{
48	atomic_set(&sl->val, 0);	53	atomic_set(&sl->val, 0);
49	#ifdef CONFIG_DEBUG_SPINLOCK	54	#ifdef CONFIG_DEBUG_SPINLOCK
50	sl->name = name;	55	sl->name = name;
51	#endif	56	#endif
52	}	57	}
53		58
54	/** Lock spinlock	59	/** Lock spinlock
55	*	60	*
56	* Lock spinlock.	61	* Lock spinlock.
57	* This version has limitted ability to report	62	* This version has limitted ability to report
58	* possible occurence of deadlock.	63	* possible occurence of deadlock.
59	*	64	*
60	* @param sl Pointer to spinlock_t structure.	65	* @param sl Pointer to spinlock_t structure.
61	*/	66	*/
62	#ifdef CONFIG_DEBUG_SPINLOCK	67	#ifdef CONFIG_DEBUG_SPINLOCK
63	void spinlock_lock_debug(spinlock_t *sl)	68	void spinlock_lock_debug(spinlock_t *sl)
64	{	69	{
65	count_t i = 0;	70	count_t i = 0;
66	char *symbol;	71	char *symbol;
67	bool deadlock_reported = false;	72	bool deadlock_reported = false;
68		73
69	preemption_disable();	74	preemption_disable();
70	while (test_and_set(&sl->val)) {	75	while (test_and_set(&sl->val)) {
71	if (i++ > 300000 && sl!=&printflock) {	76	if (i++ > 300000 && sl!=&printflock) {
72	printf("cpu%d: looping on spinlock %.p:%s, caller=%.p",	77	printf("cpu%d: looping on spinlock %.p:%s, caller=%.p",
73	CPU->id, sizeof(__address) * 2, sl, sl->name, sizeof(__address) * 2, CALLER);	78	CPU->id, sizeof(__address) * 2, sl, sl->name, sizeof(__address) * 2, CALLER);
74	symbol = get_symtab_entry(CALLER);	79	symbol = get_symtab_entry(CALLER);
75	if (symbol)	80	if (symbol)
76	printf("(%s)", symbol);	81	printf("(%s)", symbol);
77	printf("\n");	82	printf("\n");
78	i = 0;	83	i = 0;
79	deadlock_reported = true;	84	deadlock_reported = true;
80	}	85	}
81	}	86	}
82		87
83	if (deadlock_reported)	88	if (deadlock_reported)
84	printf("cpu%d: not deadlocked\n", CPU->id);	89	printf("cpu%d: not deadlocked\n", CPU->id);
85		90
86	/*	91	/*
87	* Prevent critical section code from bleeding out this way up.	92	* Prevent critical section code from bleeding out this way up.
88	*/	93	*/
89	CS_ENTER_BARRIER();	94	CS_ENTER_BARRIER();
90	}	95	}
91	#endif	96	#endif
92		97
93	/** Lock spinlock conditionally	98	/** Lock spinlock conditionally
94	*	99	*
95	* Lock spinlock conditionally.	100	* Lock spinlock conditionally.
96	* If the spinlock is not available at the moment,	101	* If the spinlock is not available at the moment,
97	* signal failure.	102	* signal failure.
98	*	103	*
99	* @param sl Pointer to spinlock_t structure.	104	* @param sl Pointer to spinlock_t structure.
100	*	105	*
101	* @return Zero on failure, non-zero otherwise.	106	* @return Zero on failure, non-zero otherwise.
102	*/	107	*/
103	int spinlock_trylock(spinlock_t *sl)	108	int spinlock_trylock(spinlock_t *sl)
104	{	109	{
105	int rc;	110	int rc;
106		111
107	preemption_disable();	112	preemption_disable();
108	rc = !test_and_set(&sl->val);	113	rc = !test_and_set(&sl->val);
109		114
110	/*	115	/*
111	* Prevent critical section code from bleeding out this way up.	116	* Prevent critical section code from bleeding out this way up.
112	*/	117	*/
113	CS_ENTER_BARRIER();	118	CS_ENTER_BARRIER();
114		119
115	if (!rc)	120	if (!rc)
116	preemption_enable();	121	preemption_enable();
117		122
118	return rc;	123	return rc;
119	}	124	}
120		125
121	#endif	126	#endif
122		127

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/synch/spinlock.c – Rev 1224 → 1264