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.
 */
 
 
 
 
 
 
 
 /** @addtogroup generic   
 * @{
 */
 
/**
 * @file
 * @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>
#include <sysinfo/sysinfo.h>
#include <arch/barrier.h>
 
/* Pointers to public variables with time */
struct ptime {
    __native seconds1;
    __native useconds;
    __native seconds2;
};
struct ptime *public_time;
/* Variable holding fragment of second, so that we would update
 * seconds correctly
 */
static __native secfrag = 0;
 
/** Initialize realtime clock counter
 *
 * The applications (and sometimes kernel) need to access accurate
 * information about realtime data. We allocate 1 page with these
 * data and update it periodically.
 *
 *
 */
void clock_counter_init(void)
{
    void *faddr;
 
    faddr = (void *)PFN2ADDR(frame_alloc(0, FRAME_ATOMIC));
    if (!faddr)
        panic("Cannot allocate page for clock");
   
    public_time = (struct ptime *)PA2KA(faddr);
 
        /* TODO: We would need some arch dependent settings here */
    public_time->seconds1 = 0;
    public_time->seconds2 = 0;
    public_time->useconds = 0;
 
    sysinfo_set_item_val("clock.faddr", NULL, (__native)faddr);
}
 
 
/** Update public counters
 *
 * Update it only on first processor
 * TODO: Do we really need so many write barriers?
 */
static void clock_update_counters(void)
{
    if (CPU->id == 0) {
        secfrag += 1000000/HZ;
        if (secfrag >= 1000000) {
            secfrag -= 1000000;
            public_time->seconds1++;
            write_barrier();
            public_time->useconds = secfrag;
            write_barrier();
            public_time->seconds2 = public_time->seconds1;
        } else
            public_time->useconds += 1000000/HZ;
    }
}
 
/** 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;
    count_t missed_clock_ticks = CPU->missed_clock_ticks;
    int i;
 
    /*
     * To avoid lock ordering problems,
     * run all expired timeouts as you visit them.
     */
    for (i = 0; i <= missed_clock_ticks; i++) {
        clock_update_counters();
        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 += 1 + missed_clock_ticks;
        spinlock_unlock(&CPU->lock);   
   
        spinlock_lock(&THREAD->lock);
        if ((ticks = THREAD->ticks)) {
            if (ticks >= 1 + missed_clock_ticks)
                THREAD->ticks -= 1 + missed_clock_ticks;
            else
                THREAD->ticks = 0;
        }
        spinlock_unlock(&THREAD->lock);
       
        if (!ticks && !PREEMPTION_DISABLED) {
            scheduler();
        }
    }
 
}
 
 /** @}
 */
 
 

Rev 1704	Rev 1705
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	/** @defgroup others Others	-
30	* @ingroup kernel	-
31	* @{	-
32	* @}	-
33	*/	-
34		-
35	/** @addtogroup generic generic	29	/** @addtogroup generic
36	* @{	30	* @{
37	*/	31	*/
38		32
39	/**	33	/**
40	* @file	34	* @file
41	* @brief High-level clock interrupt handler.	35	* @brief High-level clock interrupt handler.
42	*	36	*
43	* This file contains the clock() function which is the source	37	* This file contains the clock() function which is the source
44	* of preemption. It is also responsible for executing expired	38	* of preemption. It is also responsible for executing expired
45	* timeouts.	39	* timeouts.
46	*/	40	*/
47		41
48	#include <time/clock.h>	42	#include <time/clock.h>
49	#include <time/timeout.h>	43	#include <time/timeout.h>
50	#include <arch/types.h>	44	#include <arch/types.h>
51	#include <config.h>	45	#include <config.h>
52	#include <synch/spinlock.h>	46	#include <synch/spinlock.h>
53	#include <synch/waitq.h>	47	#include <synch/waitq.h>
54	#include <func.h>	48	#include <func.h>
55	#include <proc/scheduler.h>	49	#include <proc/scheduler.h>
56	#include <cpu.h>	50	#include <cpu.h>
57	#include <arch.h>	51	#include <arch.h>
58	#include <adt/list.h>	52	#include <adt/list.h>
59	#include <atomic.h>	53	#include <atomic.h>
60	#include <proc/thread.h>	54	#include <proc/thread.h>
61	#include <sysinfo/sysinfo.h>	55	#include <sysinfo/sysinfo.h>
62	#include <arch/barrier.h>	56	#include <arch/barrier.h>
63		57
64	/* Pointers to public variables with time */	58	/* Pointers to public variables with time */
65	struct ptime {	59	struct ptime {
66	__native seconds1;	60	__native seconds1;
67	__native useconds;	61	__native useconds;
68	__native seconds2;	62	__native seconds2;
69	};	63	};
70	struct ptime *public_time;	64	struct ptime *public_time;
71	/* Variable holding fragment of second, so that we would update	65	/* Variable holding fragment of second, so that we would update
72	* seconds correctly	66	* seconds correctly
73	*/	67	*/
74	static __native secfrag = 0;	68	static __native secfrag = 0;
75		69
76	/** Initialize realtime clock counter	70	/** Initialize realtime clock counter
77	*	71	*
78	* The applications (and sometimes kernel) need to access accurate	72	* The applications (and sometimes kernel) need to access accurate
79	* information about realtime data. We allocate 1 page with these	73	* information about realtime data. We allocate 1 page with these
80	* data and update it periodically.	74	* data and update it periodically.
81	*	75	*
82	*	76	*
83	*/	77	*/
84	void clock_counter_init(void)	78	void clock_counter_init(void)
85	{	79	{
86	void *faddr;	80	void *faddr;
87		81
88	faddr = (void *)PFN2ADDR(frame_alloc(0, FRAME_ATOMIC));	82	faddr = (void *)PFN2ADDR(frame_alloc(0, FRAME_ATOMIC));
89	if (!faddr)	83	if (!faddr)
90	panic("Cannot allocate page for clock");	84	panic("Cannot allocate page for clock");
91		85
92	public_time = (struct ptime *)PA2KA(faddr);	86	public_time = (struct ptime *)PA2KA(faddr);
93		87
94	/* TODO: We would need some arch dependent settings here */	88	/* TODO: We would need some arch dependent settings here */
95	public_time->seconds1 = 0;	89	public_time->seconds1 = 0;
96	public_time->seconds2 = 0;	90	public_time->seconds2 = 0;
97	public_time->useconds = 0;	91	public_time->useconds = 0;
98		92
99	sysinfo_set_item_val("clock.faddr", NULL, (__native)faddr);	93	sysinfo_set_item_val("clock.faddr", NULL, (__native)faddr);
100	}	94	}
101		95
102		96
103	/** Update public counters	97	/** Update public counters
104	*	98	*
105	* Update it only on first processor	99	* Update it only on first processor
106	* TODO: Do we really need so many write barriers?	100	* TODO: Do we really need so many write barriers?
107	*/	101	*/
108	static void clock_update_counters(void)	102	static void clock_update_counters(void)
109	{	103	{
110	if (CPU->id == 0) {	104	if (CPU->id == 0) {
111	secfrag += 1000000/HZ;	105	secfrag += 1000000/HZ;
112	if (secfrag >= 1000000) {	106	if (secfrag >= 1000000) {
113	secfrag -= 1000000;	107	secfrag -= 1000000;
114	public_time->seconds1++;	108	public_time->seconds1++;
115	write_barrier();	109	write_barrier();
116	public_time->useconds = secfrag;	110	public_time->useconds = secfrag;
117	write_barrier();	111	write_barrier();
118	public_time->seconds2 = public_time->seconds1;	112	public_time->seconds2 = public_time->seconds1;
119	} else	113	} else
120	public_time->useconds += 1000000/HZ;	114	public_time->useconds += 1000000/HZ;
121	}	115	}
122	}	116	}
123		117
124	/** Clock routine	118	/** Clock routine
125	*	119	*
126	* Clock routine executed from clock interrupt handler	120	* Clock routine executed from clock interrupt handler
127	* (assuming interrupts_disable()'d). Runs expired timeouts	121	* (assuming interrupts_disable()'d). Runs expired timeouts
128	* and preemptive scheduling.	122	* and preemptive scheduling.
129	*	123	*
130	*/	124	*/
131	void clock(void)	125	void clock(void)
132	{	126	{
133	link_t *l;	127	link_t *l;
134	timeout_t *h;	128	timeout_t *h;
135	timeout_handler_t f;	129	timeout_handler_t f;
136	void *arg;	130	void *arg;
137	count_t missed_clock_ticks = CPU->missed_clock_ticks;	131	count_t missed_clock_ticks = CPU->missed_clock_ticks;
138	int i;	132	int i;
139		133
140	/*	134	/*
141	* To avoid lock ordering problems,	135	* To avoid lock ordering problems,
142	* run all expired timeouts as you visit them.	136	* run all expired timeouts as you visit them.
143	*/	137	*/
144	for (i = 0; i <= missed_clock_ticks; i++) {	138	for (i = 0; i <= missed_clock_ticks; i++) {
145	clock_update_counters();	139	clock_update_counters();
146	spinlock_lock(&CPU->timeoutlock);	140	spinlock_lock(&CPU->timeoutlock);
147	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {	141	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {
148	h = list_get_instance(l, timeout_t, link);	142	h = list_get_instance(l, timeout_t, link);
149	spinlock_lock(&h->lock);	143	spinlock_lock(&h->lock);
150	if (h->ticks-- != 0) {	144	if (h->ticks-- != 0) {
151	spinlock_unlock(&h->lock);	145	spinlock_unlock(&h->lock);
152	break;	146	break;
153	}	147	}
154	list_remove(l);	148	list_remove(l);
155	f = h->handler;	149	f = h->handler;
156	arg = h->arg;	150	arg = h->arg;
157	timeout_reinitialize(h);	151	timeout_reinitialize(h);
158	spinlock_unlock(&h->lock);	152	spinlock_unlock(&h->lock);
159	spinlock_unlock(&CPU->timeoutlock);	153	spinlock_unlock(&CPU->timeoutlock);
160		154
161	f(arg);	155	f(arg);
162		156
163	spinlock_lock(&CPU->timeoutlock);	157	spinlock_lock(&CPU->timeoutlock);
164	}	158	}
165	spinlock_unlock(&CPU->timeoutlock);	159	spinlock_unlock(&CPU->timeoutlock);
166	}	160	}
167	CPU->missed_clock_ticks = 0;	161	CPU->missed_clock_ticks = 0;
168		162
169	/*	163	/*
170	* Do CPU usage accounting and find out whether to preempt THREAD.	164	* Do CPU usage accounting and find out whether to preempt THREAD.
171	*/	165	*/
172		166
173	if (THREAD) {	167	if (THREAD) {
174	__u64 ticks;	168	__u64 ticks;
175		169
176	spinlock_lock(&CPU->lock);	170	spinlock_lock(&CPU->lock);
177	CPU->needs_relink += 1 + missed_clock_ticks;	171	CPU->needs_relink += 1 + missed_clock_ticks;
178	spinlock_unlock(&CPU->lock);	172	spinlock_unlock(&CPU->lock);
179		173
180	spinlock_lock(&THREAD->lock);	174	spinlock_lock(&THREAD->lock);
181	if ((ticks = THREAD->ticks)) {	175	if ((ticks = THREAD->ticks)) {
182	if (ticks >= 1 + missed_clock_ticks)	176	if (ticks >= 1 + missed_clock_ticks)
183	THREAD->ticks -= 1 + missed_clock_ticks;	177	THREAD->ticks -= 1 + missed_clock_ticks;
184	else	178	else
185	THREAD->ticks = 0;	179	THREAD->ticks = 0;
186	}	180	}
187	spinlock_unlock(&THREAD->lock);	181	spinlock_unlock(&THREAD->lock);
188		182
189	if (!ticks && !PREEMPTION_DISABLED) {	183	if (!ticks && !PREEMPTION_DISABLED) {
190	scheduler();	184	scheduler();
191	}	185	}
192	}	186	}
193		187
194	}	188	}
195		189
196	/** @}	190	/** @}
197	*/	191	*/
198		192
199		193

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(root)/kernel/trunk/generic/src/time/clock.c – Rev 1704 → 1705