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.
 */
 
/** @defgroup others Others
 * @ingroup kernel
 * @{
 * @}
 */
 
 /** @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 1457	Rev 1702
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
-		36	* @{
-		37	*/
-		38
29	/**	39	/**
30	* @file clock.c	40	* @file
31	* @brief High-level clock interrupt handler.	41	* @brief High-level clock interrupt handler.
32	*	42	*
33	* This file contains the clock() function which is the source	43	* This file contains the clock() function which is the source
34	* of preemption. It is also responsible for executing expired	44	* of preemption. It is also responsible for executing expired
35	* timeouts.	45	* timeouts.
36	*/	46	*/
37		47
38	#include <time/clock.h>	48	#include <time/clock.h>
39	#include <time/timeout.h>	49	#include <time/timeout.h>
40	#include <arch/types.h>	50	#include <arch/types.h>
41	#include <config.h>	51	#include <config.h>
42	#include <synch/spinlock.h>	52	#include <synch/spinlock.h>
43	#include <synch/waitq.h>	53	#include <synch/waitq.h>
44	#include <func.h>	54	#include <func.h>
45	#include <proc/scheduler.h>	55	#include <proc/scheduler.h>
46	#include <cpu.h>	56	#include <cpu.h>
47	#include <arch.h>	57	#include <arch.h>
48	#include <adt/list.h>	58	#include <adt/list.h>
49	#include <atomic.h>	59	#include <atomic.h>
50	#include <proc/thread.h>	60	#include <proc/thread.h>
51	#include <sysinfo/sysinfo.h>	61	#include <sysinfo/sysinfo.h>
52	#include <arch/barrier.h>	62	#include <arch/barrier.h>
53		63
54	/* Pointers to public variables with time */	64	/* Pointers to public variables with time */
55	struct ptime {	65	struct ptime {
56	__native seconds1;	66	__native seconds1;
57	__native useconds;	67	__native useconds;
58	__native seconds2;	68	__native seconds2;
59	};	69	};
60	struct ptime *public_time;	70	struct ptime *public_time;
61	/* Variable holding fragment of second, so that we would update	71	/* Variable holding fragment of second, so that we would update
62	* seconds correctly	72	* seconds correctly
63	*/	73	*/
64	static __native secfrag = 0;	74	static __native secfrag = 0;
65		75
66	/** Initialize realtime clock counter	76	/** Initialize realtime clock counter
67	*	77	*
68	* The applications (and sometimes kernel) need to access accurate	78	* The applications (and sometimes kernel) need to access accurate
69	* information about realtime data. We allocate 1 page with these	79	* information about realtime data. We allocate 1 page with these
70	* data and update it periodically.	80	* data and update it periodically.
71	*	81	*
72	*	82	*
73	*/	83	*/
74	void clock_counter_init(void)	84	void clock_counter_init(void)
75	{	85	{
76	void *faddr;	86	void *faddr;
77		87
78	faddr = (void *)PFN2ADDR(frame_alloc(0, FRAME_ATOMIC));	88	faddr = (void *)PFN2ADDR(frame_alloc(0, FRAME_ATOMIC));
79	if (!faddr)	89	if (!faddr)
80	panic("Cannot allocate page for clock");	90	panic("Cannot allocate page for clock");
81		91
82	public_time = (struct ptime *)PA2KA(faddr);	92	public_time = (struct ptime *)PA2KA(faddr);
83		93
84	/* TODO: We would need some arch dependent settings here */	94	/* TODO: We would need some arch dependent settings here */
85	public_time->seconds1 = 0;	95	public_time->seconds1 = 0;
86	public_time->seconds2 = 0;	96	public_time->seconds2 = 0;
87	public_time->useconds = 0;	97	public_time->useconds = 0;
88		98
89	sysinfo_set_item_val("clock.faddr", NULL, (__native)faddr);	99	sysinfo_set_item_val("clock.faddr", NULL, (__native)faddr);
90	}	100	}
91		101
92		102
93	/** Update public counters	103	/** Update public counters
94	*	104	*
95	* Update it only on first processor	105	* Update it only on first processor
96	* TODO: Do we really need so many write barriers?	106	* TODO: Do we really need so many write barriers?
97	*/	107	*/
98	static void clock_update_counters(void)	108	static void clock_update_counters(void)
99	{	109	{
100	if (CPU->id == 0) {	110	if (CPU->id == 0) {
101	secfrag += 1000000/HZ;	111	secfrag += 1000000/HZ;
102	if (secfrag >= 1000000) {	112	if (secfrag >= 1000000) {
103	secfrag -= 1000000;	113	secfrag -= 1000000;
104	public_time->seconds1++;	114	public_time->seconds1++;
105	write_barrier();	115	write_barrier();
106	public_time->useconds = secfrag;	116	public_time->useconds = secfrag;
107	write_barrier();	117	write_barrier();
108	public_time->seconds2 = public_time->seconds1;	118	public_time->seconds2 = public_time->seconds1;
109	} else	119	} else
110	public_time->useconds += 1000000/HZ;	120	public_time->useconds += 1000000/HZ;
111	}	121	}
112	}	122	}
113		123
114	/** Clock routine	124	/** Clock routine
115	*	125	*
116	* Clock routine executed from clock interrupt handler	126	* Clock routine executed from clock interrupt handler
117	* (assuming interrupts_disable()'d). Runs expired timeouts	127	* (assuming interrupts_disable()'d). Runs expired timeouts
118	* and preemptive scheduling.	128	* and preemptive scheduling.
119	*	129	*
120	*/	130	*/
121	void clock(void)	131	void clock(void)
122	{	132	{
123	link_t *l;	133	link_t *l;
124	timeout_t *h;	134	timeout_t *h;
125	timeout_handler_t f;	135	timeout_handler_t f;
126	void *arg;	136	void *arg;
127	count_t missed_clock_ticks = CPU->missed_clock_ticks;	137	count_t missed_clock_ticks = CPU->missed_clock_ticks;
128	int i;	138	int i;
129		139
130	/*	140	/*
131	* To avoid lock ordering problems,	141	* To avoid lock ordering problems,
132	* run all expired timeouts as you visit them.	142	* run all expired timeouts as you visit them.
133	*/	143	*/
134	for (i = 0; i <= missed_clock_ticks; i++) {	144	for (i = 0; i <= missed_clock_ticks; i++) {
135	clock_update_counters();	145	clock_update_counters();
136	spinlock_lock(&CPU->timeoutlock);	146	spinlock_lock(&CPU->timeoutlock);
137	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {	147	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {
138	h = list_get_instance(l, timeout_t, link);	148	h = list_get_instance(l, timeout_t, link);
139	spinlock_lock(&h->lock);	149	spinlock_lock(&h->lock);
140	if (h->ticks-- != 0) {	150	if (h->ticks-- != 0) {
141	spinlock_unlock(&h->lock);	151	spinlock_unlock(&h->lock);
142	break;	152	break;
143	}	153	}
144	list_remove(l);	154	list_remove(l);
145	f = h->handler;	155	f = h->handler;
146	arg = h->arg;	156	arg = h->arg;
147	timeout_reinitialize(h);	157	timeout_reinitialize(h);
148	spinlock_unlock(&h->lock);	158	spinlock_unlock(&h->lock);
149	spinlock_unlock(&CPU->timeoutlock);	159	spinlock_unlock(&CPU->timeoutlock);
150		160
151	f(arg);	161	f(arg);
152		162
153	spinlock_lock(&CPU->timeoutlock);	163	spinlock_lock(&CPU->timeoutlock);
154	}	164	}
155	spinlock_unlock(&CPU->timeoutlock);	165	spinlock_unlock(&CPU->timeoutlock);
156	}	166	}
157	CPU->missed_clock_ticks = 0;	167	CPU->missed_clock_ticks = 0;
158		168
159	/*	169	/*
160	* Do CPU usage accounting and find out whether to preempt THREAD.	170	* Do CPU usage accounting and find out whether to preempt THREAD.
161	*/	171	*/
162		172
163	if (THREAD) {	173	if (THREAD) {
164	__u64 ticks;	174	__u64 ticks;
165		175
166	spinlock_lock(&CPU->lock);	176	spinlock_lock(&CPU->lock);
167	CPU->needs_relink += 1 + missed_clock_ticks;	177	CPU->needs_relink += 1 + missed_clock_ticks;
168	spinlock_unlock(&CPU->lock);	178	spinlock_unlock(&CPU->lock);
169		179
170	spinlock_lock(&THREAD->lock);	180	spinlock_lock(&THREAD->lock);
171	if ((ticks = THREAD->ticks)) {	181	if ((ticks = THREAD->ticks)) {
172	if (ticks >= 1 + missed_clock_ticks)	182	if (ticks >= 1 + missed_clock_ticks)
173	THREAD->ticks -= 1 + missed_clock_ticks;	183	THREAD->ticks -= 1 + missed_clock_ticks;
174	else	184	else
175	THREAD->ticks = 0;	185	THREAD->ticks = 0;
176	}	186	}
177	spinlock_unlock(&THREAD->lock);	187	spinlock_unlock(&THREAD->lock);
178		188
179	if (!ticks && !PREEMPTION_DISABLED) {	189	if (!ticks && !PREEMPTION_DISABLED) {
180	scheduler();	190	scheduler();
181	}	191	}
182	}	192	}
183		193
184	}	194	}
-		195
-		196	/** @}
-		197	*/
-		198
185		199

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(root)/kernel/trunk/generic/src/time/clock.c – Rev 1457 → 1702