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.
 */
 
#include <synch/spinlock.h>
#include <arch/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  
}
 
#ifdef CONFIG_DEBUG_SPINLOCK
/** Lock spinlock
 *
 * Lock spinlock.
 * This version has limitted ability to report
 * possible occurence of deadlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
void spinlock_lock(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, sl, sl->name, 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();
 
}
 
#else
 
/** Lock spinlock
 *
 * Lock spinlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
void spinlock_lock(spinlock_t *sl)
{
    preemption_disable();
 
    /*
     * Each architecture has its own efficient/recommended
     * implementation of spinlock.
     */
    spinlock_arch(&sl->val);
 
    /*
     * 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;
}
 
/** Unlock spinlock
 *
 * Unlock spinlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
void spinlock_unlock(spinlock_t *sl)
{
    ASSERT(atomic_get(&sl->val) != 0);
 
    /*
     * Prevent critical section code from bleeding out this way down.
     */
    CS_LEAVE_BARRIER();
   
    atomic_set(&sl->val,0);
    preemption_enable();
}
 
#endif
 

Rev 625	Rev 787
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	#include <synch/spinlock.h>	29	#include <synch/spinlock.h>
30	#include <arch/atomic.h>	30	#include <arch/atomic.h>
31	#include <arch/barrier.h>	31	#include <arch/barrier.h>
32	#include <arch.h>	32	#include <arch.h>
33	#include <preemption.h>	33	#include <preemption.h>
34	#include <print.h>	34	#include <print.h>
35	#include <debug.h>	35	#include <debug.h>
36	#include <symtab.h>	36	#include <symtab.h>
37		37
38	#ifdef CONFIG_SMP	38	#ifdef CONFIG_SMP
39		39
40	/** Initialize spinlock	40	/** Initialize spinlock
41	*	41	*
42	* Initialize spinlock.	42	* Initialize spinlock.
43	*	43	*
44	* @param sl Pointer to spinlock_t structure.	44	* @param sl Pointer to spinlock_t structure.
45	*/	45	*/
46	void spinlock_initialize(spinlock_t sl, char name)	46	void spinlock_initialize(spinlock_t sl, char name)
47	{	47	{
48	atomic_set(&sl->val, 0);	48	atomic_set(&sl->val, 0);
49	#ifdef CONFIG_DEBUG_SPINLOCK	49	#ifdef CONFIG_DEBUG_SPINLOCK
50	sl->name = name;	50	sl->name = name;
51	#endif	51	#endif
52	}	52	}
53		53
54	#ifdef CONFIG_DEBUG_SPINLOCK	54	#ifdef CONFIG_DEBUG_SPINLOCK
55	/** Lock spinlock	55	/** Lock spinlock
56	*	56	*
57	* Lock spinlock.	57	* Lock spinlock.
58	* This version has limitted ability to report	58	* This version has limitted ability to report
59	* possible occurence of deadlock.	59	* possible occurence of deadlock.
60	*	60	*
61	* @param sl Pointer to spinlock_t structure.	61	* @param sl Pointer to spinlock_t structure.
62	*/	62	*/
63	void spinlock_lock(spinlock_t *sl)	63	void spinlock_lock(spinlock_t *sl)
64	{	64	{
65	count_t i = 0;	65	count_t i = 0;
66	char *symbol;	66	char *symbol;
67	bool deadlock_reported = false;	67	bool deadlock_reported = false;
68		68
69	preemption_disable();	69	preemption_disable();
70	while (test_and_set(&sl->val)) {	70	while (test_and_set(&sl->val)) {
71	if (i++ > 300000) {	71	if (i++ > 300000 && sl!=&printflock) {
72	printf("cpu%d: looping on spinlock %p:%s, caller=%p",	72	printf("cpu%d: looping on spinlock %p:%s, caller=%p",
73	CPU->id, sl, sl->name, CALLER);	73	CPU->id, sl, sl->name, CALLER);
74	symbol = get_symtab_entry(CALLER);	74	symbol = get_symtab_entry(CALLER);
75	if (symbol)	75	if (symbol)
76	printf("(%s)", symbol);	76	printf("(%s)", symbol);
77	printf("\n");	77	printf("\n");
78	i = 0;	78	i = 0;
79	deadlock_reported = true;	79	deadlock_reported = true;
80	}	80	}
81	}	81	}
82		82
83	if (deadlock_reported)	83	if (deadlock_reported)
84	printf("cpu%d: not deadlocked\n", CPU->id);	84	printf("cpu%d: not deadlocked\n", CPU->id);
85		85
86	/*	86	/*
87	* Prevent critical section code from bleeding out this way up.	87	* Prevent critical section code from bleeding out this way up.
88	*/	88	*/
89	CS_ENTER_BARRIER();	89	CS_ENTER_BARRIER();
90		90
91	}	91	}
92		92
93	#else	93	#else
94		94
95	/** Lock spinlock	95	/** Lock spinlock
96	*	96	*
97	* Lock spinlock.	97	* Lock spinlock.
98	*	98	*
99	* @param sl Pointer to spinlock_t structure.	99	* @param sl Pointer to spinlock_t structure.
100	*/	100	*/
101	void spinlock_lock(spinlock_t *sl)	101	void spinlock_lock(spinlock_t *sl)
102	{	102	{
103	preemption_disable();	103	preemption_disable();
104		104
105	/*	105	/*
106	* Each architecture has its own efficient/recommended	106	* Each architecture has its own efficient/recommended
107	* implementation of spinlock.	107	* implementation of spinlock.
108	*/	108	*/
109	spinlock_arch(&sl->val);	109	spinlock_arch(&sl->val);
110		110
111	/*	111	/*
112	* Prevent critical section code from bleeding out this way up.	112	* Prevent critical section code from bleeding out this way up.
113	*/	113	*/
114	CS_ENTER_BARRIER();	114	CS_ENTER_BARRIER();
115	}	115	}
116	#endif	116	#endif
117		117
118	/** Lock spinlock conditionally	118	/** Lock spinlock conditionally
119	*	119	*
120	* Lock spinlock conditionally.	120	* Lock spinlock conditionally.
121	* If the spinlock is not available at the moment,	121	* If the spinlock is not available at the moment,
122	* signal failure.	122	* signal failure.
123	*	123	*
124	* @param sl Pointer to spinlock_t structure.	124	* @param sl Pointer to spinlock_t structure.
125	*	125	*
126	* @return Zero on failure, non-zero otherwise.	126	* @return Zero on failure, non-zero otherwise.
127	*/	127	*/
128	int spinlock_trylock(spinlock_t *sl)	128	int spinlock_trylock(spinlock_t *sl)
129	{	129	{
130	int rc;	130	int rc;
131		131
132	preemption_disable();	132	preemption_disable();
133	rc = !test_and_set(&sl->val);	133	rc = !test_and_set(&sl->val);
134		134
135	/*	135	/*
136	* Prevent critical section code from bleeding out this way up.	136	* Prevent critical section code from bleeding out this way up.
137	*/	137	*/
138	CS_ENTER_BARRIER();	138	CS_ENTER_BARRIER();
139		139
140	if (!rc)	140	if (!rc)
141	preemption_enable();	141	preemption_enable();
142		142
143	return rc;	143	return rc;
144	}	144	}
145		145
146	/** Unlock spinlock	146	/** Unlock spinlock
147	*	147	*
148	* Unlock spinlock.	148	* Unlock spinlock.
149	*	149	*
150	* @param sl Pointer to spinlock_t structure.	150	* @param sl Pointer to spinlock_t structure.
151	*/	151	*/
152	void spinlock_unlock(spinlock_t *sl)	152	void spinlock_unlock(spinlock_t *sl)
153	{	153	{
154	ASSERT(atomic_get(&sl->val) != 0);	154	ASSERT(atomic_get(&sl->val) != 0);
155		155
156	/*	156	/*
157	* Prevent critical section code from bleeding out this way down.	157	* Prevent critical section code from bleeding out this way down.
158	*/	158	*/
159	CS_LEAVE_BARRIER();	159	CS_LEAVE_BARRIER();
160		160
161	atomic_set(&sl->val,0);	161	atomic_set(&sl->val,0);
162	preemption_enable();	162	preemption_enable();
163	}	163	}
164		164
165	#endif	165	#endif
166		166

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/synch/spinlock.c – Rev 625 → 787