WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/time/clock.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    clock.c
 * @brief   High-level clock interrupt handler.
 *
 * This file contains the clock() function which is the source
 * of preemption. It is also responsible for executing expired
 * timeouts.
 */
 
#include <time/clock.h>
#include <time/timeout.h>
#include <arch/types.h>
#include <config.h>
#include <synch/spinlock.h>
#include <synch/waitq.h>
#include <func.h>
#include <proc/scheduler.h>
#include <cpu.h>
#include <arch.h>
#include <adt/list.h>
#include <atomic.h>
#include <proc/thread.h>
 
/** Clock routine
 *
 * Clock routine executed from clock interrupt handler
 * (assuming interrupts_disable()'d). Runs expired timeouts
 * and preemptive scheduling.
 *
 */
void clock(void)
{
    link_t *l;
    timeout_t *h;
    timeout_handler_t f;
    void *arg;
    int i;
 
    /*
     * To avoid lock ordering problems,
     * run all expired timeouts as you visit them.
     */
    for (i = 0; i < CPU->missed_clock_ticks; i++) {
        spinlock_lock(&CPU->timeoutlock);
        while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {
            h = list_get_instance(l, timeout_t, link);
            spinlock_lock(&h->lock);
            if (h->ticks-- != 0) {
                spinlock_unlock(&h->lock);
                break;
            }
            list_remove(l);
            f = h->handler;
            arg = h->arg;
            timeout_reinitialize(h);
            spinlock_unlock(&h->lock); 
            spinlock_unlock(&CPU->timeoutlock);
 
            f(arg);
 
            spinlock_lock(&CPU->timeoutlock);
        }
        spinlock_unlock(&CPU->timeoutlock);
    }
    CPU->missed_clock_ticks = 0;
 
    /*
     * Do CPU usage accounting and find out whether to preempt THREAD.
     */
 
    if (THREAD) {
        __u64 ticks;
       
        spinlock_lock(&CPU->lock);
        CPU->needs_relink++;
        spinlock_unlock(&CPU->lock);   
   
        spinlock_lock(&THREAD->lock);
        if ((ticks = THREAD->ticks))
            THREAD->ticks--;
        spinlock_unlock(&THREAD->lock);
       
        if (!ticks && !PREEMPTION_DISABLED) {
            scheduler();
        }
    }
 
}
 

Rev 1264	Rev 1431
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	/**	29	/**
30	* @file clock.c	30	* @file clock.c
31	* @brief High-level clock interrupt handler.	31	* @brief High-level clock interrupt handler.
32	*	32	*
33	* This file contains the clock() function which is the source	33	* This file contains the clock() function which is the source
34	* of preemption. It is also responsible for executing expired	34	* of preemption. It is also responsible for executing expired
35	* timeouts.	35	* timeouts.
36	*/	36	*/
37		37
38	#include <time/clock.h>	38	#include <time/clock.h>
39	#include <time/timeout.h>	39	#include <time/timeout.h>
40	#include <arch/types.h>	40	#include <arch/types.h>
41	#include <config.h>	41	#include <config.h>
42	#include <synch/spinlock.h>	42	#include <synch/spinlock.h>
43	#include <synch/waitq.h>	43	#include <synch/waitq.h>
44	#include <func.h>	44	#include <func.h>
45	#include <proc/scheduler.h>	45	#include <proc/scheduler.h>
46	#include <cpu.h>	46	#include <cpu.h>
47	#include <arch.h>	47	#include <arch.h>
48	#include <adt/list.h>	48	#include <adt/list.h>
49	#include <atomic.h>	49	#include <atomic.h>
50	#include <proc/thread.h>	50	#include <proc/thread.h>
51		51
52	/** Clock routine	52	/** Clock routine
53	*	53	*
54	* Clock routine executed from clock interrupt handler	54	* Clock routine executed from clock interrupt handler
55	* (assuming interrupts_disable()'d). Runs expired timeouts	55	* (assuming interrupts_disable()'d). Runs expired timeouts
56	* and preemptive scheduling.	56	* and preemptive scheduling.
57	*	57	*
58	*/	58	*/
59	void clock(void)	59	void clock(void)
60	{	60	{
61	link_t *l;	61	link_t *l;
62	timeout_t *h;	62	timeout_t *h;
63	timeout_handler_t f;	63	timeout_handler_t f;
64	void *arg;	64	void *arg;
-		65	int i;
65		66
66	/*	67	/*
67	* To avoid lock ordering problems,	68	* To avoid lock ordering problems,
68	* run all expired timeouts as you visit them.	69	* run all expired timeouts as you visit them.
69	*/	70	*/
-		71	for (i = 0; i < CPU->missed_clock_ticks; i++) {
70	spinlock_lock(&CPU->timeoutlock);	72	spinlock_lock(&CPU->timeoutlock);
71	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {	73	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {
72	h = list_get_instance(l, timeout_t, link);	74	h = list_get_instance(l, timeout_t, link);
73	spinlock_lock(&h->lock);	75	spinlock_lock(&h->lock);
74	if (h->ticks-- != 0) {	76	if (h->ticks-- != 0) {
75	spinlock_unlock(&h->lock);	77	spinlock_unlock(&h->lock);
76	break;	78	break;
77	}	79	}
78	list_remove(l);	80	list_remove(l);
79	f = h->handler;	81	f = h->handler;
80	arg = h->arg;	82	arg = h->arg;
81	timeout_reinitialize(h);	83	timeout_reinitialize(h);
82	spinlock_unlock(&h->lock);	84	spinlock_unlock(&h->lock);
83	spinlock_unlock(&CPU->timeoutlock);	85	spinlock_unlock(&CPU->timeoutlock);
84		86
85	f(arg);	87	f(arg);
86		88
87	spinlock_lock(&CPU->timeoutlock);	89	spinlock_lock(&CPU->timeoutlock);
-		90	}
-		91	spinlock_unlock(&CPU->timeoutlock);
88	}	92	}
89	spinlock_unlock(&CPU->timeoutlock);	93	CPU->missed_clock_ticks = 0;
90		94
91	/*	95	/*
92	* Do CPU usage accounting and find out whether to preempt THREAD.	96	* Do CPU usage accounting and find out whether to preempt THREAD.
93	*/	97	*/
94		98
95	if (THREAD) {	99	if (THREAD) {
96	__u64 ticks;	100	__u64 ticks;
97		101
98	spinlock_lock(&CPU->lock);	102	spinlock_lock(&CPU->lock);
99	CPU->needs_relink++;	103	CPU->needs_relink++;
100	spinlock_unlock(&CPU->lock);	104	spinlock_unlock(&CPU->lock);
101		105
102	spinlock_lock(&THREAD->lock);	106	spinlock_lock(&THREAD->lock);
103	if ((ticks = THREAD->ticks))	107	if ((ticks = THREAD->ticks))
104	THREAD->ticks--;	108	THREAD->ticks--;
105	spinlock_unlock(&THREAD->lock);	109	spinlock_unlock(&THREAD->lock);
106		110
107	if (!ticks && !PREEMPTION_DISABLED) {	111	if (!ticks && !PREEMPTION_DISABLED) {
108	scheduler();	112	scheduler();
109	}	113	}
110	}	114	}
111		115
112	}	116	}
113		117

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/time/clock.c @ 1757 – Rev 1264 → 1431