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)
{
    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;
    __address caller = ((__address *) &sl)[-1];
    char *symbol;
    bool deadlock_reported = false;
 
    preemption_disable();
    while (test_and_set(&sl->val)) {
        if (i++ > 300000) {
            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(sl->val != 0);
 
    /*
     * Prevent critical section code from bleeding out this way down.
     */
    CS_LEAVE_BARRIER();
   
    sl->val = 0;
    preemption_enable();
}
 
#endif
 

Rev 552	Rev 557
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	sl->val = 0;	48	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	int i = 0;	65	count_t i = 0;
66	__address caller = ((__address *) &sl)[-1];	66	__address caller = ((__address *) &sl)[-1];
67	char *symbol;	67	char *symbol;
-		68	bool deadlock_reported = false;
68		69
69	preemption_disable();	70	preemption_disable();
70	while (test_and_set(&sl->val)) {	71	while (test_and_set(&sl->val)) {
71	if (i++ > 300000) {	72	if (i++ > 300000) {
72	printf("cpu%d: looping on spinlock %p:%s, caller=%p",	73	printf("cpu%d: looping on spinlock %p:%s, caller=%p",
73	CPU->id, sl, sl->name, caller);	74	CPU->id, sl, sl->name, caller);
74	symbol = get_symtab_entry(caller);	75	symbol = get_symtab_entry(caller);
75	if (symbol)	76	if (symbol)
76	printf("(%s)", symbol);	77	printf("(%s)", symbol);
77	printf("\n");	78	printf("\n");
78	i = 0;	79	i = 0;
-		80	deadlock_reported = true;
79	}	81	}
80	}	82	}
81		83
-		84	if (deadlock_reported)
-		85	printf("cpu%d: not deadlocked\n", CPU->id);
-		86
82	/*	87	/*
83	* Prevent critical section code from bleeding out this way up.	88	* Prevent critical section code from bleeding out this way up.
84	*/	89	*/
85	CS_ENTER_BARRIER();	90	CS_ENTER_BARRIER();
86		91
87	}	92	}
88		93
89	#else	94	#else
90		95
91	/** Lock spinlock	96	/** Lock spinlock
92	*	97	*
93	* Lock spinlock.	98	* Lock spinlock.
94	*	99	*
95	* @param sl Pointer to spinlock_t structure.	100	* @param sl Pointer to spinlock_t structure.
96	*/	101	*/
97	void spinlock_lock(spinlock_t *sl)	102	void spinlock_lock(spinlock_t *sl)
98	{	103	{
99	preemption_disable();	104	preemption_disable();
100		105
101	/*	106	/*
102	* Each architecture has its own efficient/recommended	107	* Each architecture has its own efficient/recommended
103	* implementation of spinlock.	108	* implementation of spinlock.
104	*/	109	*/
105	spinlock_arch(&sl->val);	110	spinlock_arch(&sl->val);
106		111
107	/*	112	/*
108	* Prevent critical section code from bleeding out this way up.	113	* Prevent critical section code from bleeding out this way up.
109	*/	114	*/
110	CS_ENTER_BARRIER();	115	CS_ENTER_BARRIER();
111	}	116	}
112	#endif	117	#endif
113		118
114	/** Lock spinlock conditionally	119	/** Lock spinlock conditionally
115	*	120	*
116	* Lock spinlock conditionally.	121	* Lock spinlock conditionally.
117	* If the spinlock is not available at the moment,	122	* If the spinlock is not available at the moment,
118	* signal failure.	123	* signal failure.
119	*	124	*
120	* @param sl Pointer to spinlock_t structure.	125	* @param sl Pointer to spinlock_t structure.
121	*	126	*
122	* @return Zero on failure, non-zero otherwise.	127	* @return Zero on failure, non-zero otherwise.
123	*/	128	*/
124	int spinlock_trylock(spinlock_t *sl)	129	int spinlock_trylock(spinlock_t *sl)
125	{	130	{
126	int rc;	131	int rc;
127		132
128	preemption_disable();	133	preemption_disable();
129	rc = !test_and_set(&sl->val);	134	rc = !test_and_set(&sl->val);
130		135
131	/*	136	/*
132	* Prevent critical section code from bleeding out this way up.	137	* Prevent critical section code from bleeding out this way up.
133	*/	138	*/
134	CS_ENTER_BARRIER();	139	CS_ENTER_BARRIER();
135		140
136	if (!rc)	141	if (!rc)
137	preemption_enable();	142	preemption_enable();
138		143
139	return rc;	144	return rc;
140	}	145	}
141		146
142	/** Unlock spinlock	147	/** Unlock spinlock
143	*	148	*
144	* Unlock spinlock.	149	* Unlock spinlock.
145	*	150	*
146	* @param sl Pointer to spinlock_t structure.	151	* @param sl Pointer to spinlock_t structure.
147	*/	152	*/
148	void spinlock_unlock(spinlock_t *sl)	153	void spinlock_unlock(spinlock_t *sl)
149	{	154	{
150	ASSERT(sl->val != 0);	155	ASSERT(sl->val != 0);
151		156
152	/*	157	/*
153	* Prevent critical section code from bleeding out this way down.	158	* Prevent critical section code from bleeding out this way down.
154	*/	159	*/
155	CS_LEAVE_BARRIER();	160	CS_LEAVE_BARRIER();
156		161
157	sl->val = 0;	162	sl->val = 0;
158	preemption_enable();	163	preemption_enable();
159	}	164	}
160		165
161	#endif	166	#endif
162		167

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(root)/kernel/trunk/generic/src/synch/spinlock.c @ 1757 – Rev 552 → 557