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;
 
    /*
     * To avoid lock ordering problems,
     * run all expired timeouts as you visit them.
     */
    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);
 
    /*
     * 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 1196	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 clock.c
-		31	* @brief High-level clock interrupt handler.
-		32	*
-		33	* This file contains the clock() function which is the source
-		34	* of preemption. It is also responsible for executing expired
-		35	* timeouts.
-		36	*/
-		37
29	#include <time/clock.h>	38	#include <time/clock.h>
30	#include <time/timeout.h>	39	#include <time/timeout.h>
31	#include <arch/types.h>	40	#include <arch/types.h>
32	#include <config.h>	41	#include <config.h>
33	#include <synch/spinlock.h>	42	#include <synch/spinlock.h>
34	#include <synch/waitq.h>	43	#include <synch/waitq.h>
35	#include <func.h>	44	#include <func.h>
36	#include <proc/scheduler.h>	45	#include <proc/scheduler.h>
37	#include <cpu.h>	46	#include <cpu.h>
38	#include <arch.h>	47	#include <arch.h>
39	#include <adt/list.h>	48	#include <adt/list.h>
40	#include <atomic.h>	49	#include <atomic.h>
41	#include <proc/thread.h>	50	#include <proc/thread.h>
42		51
43	/** Clock routine	52	/** Clock routine
44	*	53	*
45	* Clock routine executed from clock interrupt handler	54	* Clock routine executed from clock interrupt handler
46	* (assuming interrupts_disable()'d). Runs expired timeouts	55	* (assuming interrupts_disable()'d). Runs expired timeouts
47	* and preemptive scheduling.	56	* and preemptive scheduling.
48	*	57	*
49	*/	58	*/
50	void clock(void)	59	void clock(void)
51	{	60	{
52	link_t *l;	61	link_t *l;
53	timeout_t *h;	62	timeout_t *h;
54	timeout_handler_t f;	63	timeout_handler_t f;
55	void *arg;	64	void *arg;
56		65
57	/*	66	/*
58	* To avoid lock ordering problems,	67	* To avoid lock ordering problems,
59	* run all expired timeouts as you visit them.	68	* run all expired timeouts as you visit them.
60	*/	69	*/
61	spinlock_lock(&CPU->timeoutlock);	70	spinlock_lock(&CPU->timeoutlock);
62	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {	71	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {
63	h = list_get_instance(l, timeout_t, link);	72	h = list_get_instance(l, timeout_t, link);
64	spinlock_lock(&h->lock);	73	spinlock_lock(&h->lock);
65	if (h->ticks-- != 0) {	74	if (h->ticks-- != 0) {
66	spinlock_unlock(&h->lock);	75	spinlock_unlock(&h->lock);
67	break;	76	break;
68	}	77	}
69	list_remove(l);	78	list_remove(l);
70	f = h->handler;	79	f = h->handler;
71	arg = h->arg;	80	arg = h->arg;
72	timeout_reinitialize(h);	81	timeout_reinitialize(h);
73	spinlock_unlock(&h->lock);	82	spinlock_unlock(&h->lock);
74	spinlock_unlock(&CPU->timeoutlock);	83	spinlock_unlock(&CPU->timeoutlock);
75		84
76	f(arg);	85	f(arg);
77		86
78	spinlock_lock(&CPU->timeoutlock);	87	spinlock_lock(&CPU->timeoutlock);
79	}	88	}
80	spinlock_unlock(&CPU->timeoutlock);	89	spinlock_unlock(&CPU->timeoutlock);
81		90
82	/*	91	/*
83	* Do CPU usage accounting and find out whether to preempt THREAD.	92	* Do CPU usage accounting and find out whether to preempt THREAD.
84	*/	93	*/
85		94
86	if (THREAD) {	95	if (THREAD) {
87	__u64 ticks;	96	__u64 ticks;
88		97
89	spinlock_lock(&CPU->lock);	98	spinlock_lock(&CPU->lock);
90	CPU->needs_relink++;	99	CPU->needs_relink++;
91	spinlock_unlock(&CPU->lock);	100	spinlock_unlock(&CPU->lock);
92		101
93	spinlock_lock(&THREAD->lock);	102	spinlock_lock(&THREAD->lock);
94	if ((ticks = THREAD->ticks))	103	if ((ticks = THREAD->ticks))
95	THREAD->ticks--;	104	THREAD->ticks--;
96	spinlock_unlock(&THREAD->lock);	105	spinlock_unlock(&THREAD->lock);
97		106
98	if (!ticks && !PREEMPTION_DISABLED) {	107	if (!ticks && !PREEMPTION_DISABLED) {
99	scheduler();	108	scheduler();
100	}	109	}
101	}	110	}
102		111
103	}	112	}
104		113

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/time/clock.c @ 1731 – Rev 1196 → 1264