WebSVN – HelenOS-historic – Diff – /uspace/trunk/libc/generic/time.c


/*
 * Copyright (C) 2006 Ondrej Palkovsky
 * 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 libc
 * @{
 */
/** @file
 */
 
#include <sys/time.h>
#include <unistd.h>
#include <ipc/ipc.h>
#include <stdio.h>
#include <arch/barrier.h>
#include <unistd.h>
#include <atomic.h>
#include <futex.h>
#include <ipc/services.h>
 
#include <sysinfo.h>
#include <as.h>
#include <ddi.h>
 
/* Pointers to public variables with time */
struct {
    volatile sysarg_t seconds1;
    volatile sysarg_t useconds;
    volatile sysarg_t seconds2;
} *ktime = NULL;
 
 
/** POSIX gettimeofday
 *
 * The time variables are memory mapped(RO) from kernel, which updates
 * them periodically. As it is impossible to read 2 values atomically, we
 * use a trick: First read a seconds, then read microseconds, then
 * read seconds again. If a second elapsed in the meantime, read
 * useconds again. This provides assurance, that at least the
 * sequence of subsequent gettimeofday calls is ordered.
 */
int gettimeofday(struct timeval *tv, struct timezone *tz)
{
    void *mapping;
    sysarg_t s1, s2;
    sysarg_t rights;
    int res;
 
    if (!ktime) {
        mapping = as_get_mappable_page(PAGE_SIZE);
        /* Get the mapping of kernel clock */
        res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV,
                      mapping, PAGE_SIZE, SERVICE_MEM_REALTIME,
                      NULL,&rights,NULL);
        if (res) {
            printf("Failed to initialize timeofday memarea\n");
            _exit(1);
        }
        if (! (rights & AS_AREA_READ)) {
            printf("Received bad rights on time area: %X\n",
                   rights);
            as_area_destroy(mapping);
            _exit(1);
        }
        ktime = mapping;
    }
    if (tz) {
        tz->tz_minuteswest = 0;
        tz->tz_dsttime = DST_NONE;
    }
 
    s2 = ktime->seconds2;
    read_barrier();
    tv->tv_usec = ktime->useconds;
    read_barrier();
    s1 = ktime->seconds1;
    if (s1 != s2) {
        tv->tv_usec = 0;
        tv->tv_sec = s1 > s2 ? s1 : s2;
    } else
        tv->tv_sec = s1;
 
    return 0;
}
 
/** Wait unconditionally for specified microseconds */
void usleep(unsigned long usec)
{
    atomic_t futex = FUTEX_INITIALIZER;
 
    futex_initialize(&futex,0);
    futex_down_timeout(&futex, usec, 0);
}
 
 
 /** @}
 */
 
 
 

Rev 1596	Rev 1653
1	/*	1	/*
2	* Copyright (C) 2006 Ondrej Palkovsky	2	* Copyright (C) 2006 Ondrej Palkovsky
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	*/
-		28
-		29	/** @addtogroup libc
-		30	* @{
-		31	*/
-		32	/** @file
27	*/	33	*/
28		34
29	#include <sys/time.h>	35	#include <sys/time.h>
30	#include <unistd.h>	36	#include <unistd.h>
31	#include <ipc/ipc.h>	37	#include <ipc/ipc.h>
32	#include <stdio.h>	38	#include <stdio.h>
33	#include <arch/barrier.h>	39	#include <arch/barrier.h>
34	#include <unistd.h>	40	#include <unistd.h>
35	#include <atomic.h>	41	#include <atomic.h>
36	#include <futex.h>	42	#include <futex.h>
37	#include <ipc/services.h>	43	#include <ipc/services.h>
38		44
39	#include <sysinfo.h>	45	#include <sysinfo.h>
40	#include <as.h>	46	#include <as.h>
41	#include <ddi.h>	47	#include <ddi.h>
42		48
43	/* Pointers to public variables with time */	49	/* Pointers to public variables with time */
44	struct {	50	struct {
45	volatile sysarg_t seconds1;	51	volatile sysarg_t seconds1;
46	volatile sysarg_t useconds;	52	volatile sysarg_t useconds;
47	volatile sysarg_t seconds2;	53	volatile sysarg_t seconds2;
48	} *ktime = NULL;	54	} *ktime = NULL;
49		55
50		56
51	/** POSIX gettimeofday	57	/** POSIX gettimeofday
52	*	58	*
53	* The time variables are memory mapped(RO) from kernel, which updates	59	* The time variables are memory mapped(RO) from kernel, which updates
54	* them periodically. As it is impossible to read 2 values atomically, we	60	* them periodically. As it is impossible to read 2 values atomically, we
55	* use a trick: First read a seconds, then read microseconds, then	61	* use a trick: First read a seconds, then read microseconds, then
56	* read seconds again. If a second elapsed in the meantime, read	62	* read seconds again. If a second elapsed in the meantime, read
57	* useconds again. This provides assurance, that at least the	63	* useconds again. This provides assurance, that at least the
58	* sequence of subsequent gettimeofday calls is ordered.	64	* sequence of subsequent gettimeofday calls is ordered.
59	*/	65	*/
60	int gettimeofday(struct timeval tv, struct timezone tz)	66	int gettimeofday(struct timeval tv, struct timezone tz)
61	{	67	{
62	void *mapping;	68	void *mapping;
63	sysarg_t s1, s2;	69	sysarg_t s1, s2;
64	sysarg_t rights;	70	sysarg_t rights;
65	int res;	71	int res;
66		72
67	if (!ktime) {	73	if (!ktime) {
68	mapping = as_get_mappable_page(PAGE_SIZE);	74	mapping = as_get_mappable_page(PAGE_SIZE);
69	/* Get the mapping of kernel clock */	75	/* Get the mapping of kernel clock */
70	res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV,	76	res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV,
71	mapping, PAGE_SIZE, SERVICE_MEM_REALTIME,	77	mapping, PAGE_SIZE, SERVICE_MEM_REALTIME,
72	NULL,&rights,NULL);	78	NULL,&rights,NULL);
73	if (res) {	79	if (res) {
74	printf("Failed to initialize timeofday memarea\n");	80	printf("Failed to initialize timeofday memarea\n");
75	_exit(1);	81	_exit(1);
76	}	82	}
77	if (! (rights & AS_AREA_READ)) {	83	if (! (rights & AS_AREA_READ)) {
78	printf("Received bad rights on time area: %X\n",	84	printf("Received bad rights on time area: %X\n",
79	rights);	85	rights);
80	as_area_destroy(mapping);	86	as_area_destroy(mapping);
81	_exit(1);	87	_exit(1);
82	}	88	}
83	ktime = mapping;	89	ktime = mapping;
84	}	90	}
85	if (tz) {	91	if (tz) {
86	tz->tz_minuteswest = 0;	92	tz->tz_minuteswest = 0;
87	tz->tz_dsttime = DST_NONE;	93	tz->tz_dsttime = DST_NONE;
88	}	94	}
89		95
90	s2 = ktime->seconds2;	96	s2 = ktime->seconds2;
91	read_barrier();	97	read_barrier();
92	tv->tv_usec = ktime->useconds;	98	tv->tv_usec = ktime->useconds;
93	read_barrier();	99	read_barrier();
94	s1 = ktime->seconds1;	100	s1 = ktime->seconds1;
95	if (s1 != s2) {	101	if (s1 != s2) {
96	tv->tv_usec = 0;	102	tv->tv_usec = 0;
97	tv->tv_sec = s1 > s2 ? s1 : s2;	103	tv->tv_sec = s1 > s2 ? s1 : s2;
98	} else	104	} else
99	tv->tv_sec = s1;	105	tv->tv_sec = s1;
100		106
101	return 0;	107	return 0;
102	}	108	}
103		109
104	/** Wait unconditionally for specified microseconds */	110	/** Wait unconditionally for specified microseconds */
105	void usleep(unsigned long usec)	111	void usleep(unsigned long usec)
106	{	112	{
107	atomic_t futex = FUTEX_INITIALIZER;	113	atomic_t futex = FUTEX_INITIALIZER;
108		114
109	futex_initialize(&futex,0);	115	futex_initialize(&futex,0);
110	futex_down_timeout(&futex, usec, 0);	116	futex_down_timeout(&futex, usec, 0);
111	}	117	}
-		118
-		119
-		120	/** @}
-		121	*/
-		122
-		123
112		124

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libc/generic/time.c – Rev 1596 → 1653