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.
 */
 
#include <sys/time.h>
#include <unistd.h>
#include <ipc/ipc.h>
#include <stdio.h>
#include <arch/barrier.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.
 */
#define TMAREA (100*1024*1024)
int gettimeofday(struct timeval *tv, struct timezone *tz)
{
    void *mapping;
    sysarg_t s1, s2;
    sysarg_t t1;
    int res;
 
    if (!ktime) {
        /* TODO: specify better, where to map the area */
        /* Get the mapping of kernel clock */
        res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV,
                      TMAREA,
                      PAGE_SIZE,
                      AS_AREA_READ | AS_AREA_CACHEABLE,
                      &t1,&t1,&t1);
        if (res) {
            printf("Failed to initialize timeofday memarea\n");
            _exit(1);
        }
        ktime = (void *) (TMAREA);
    }
    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;
}
 

Rev 1442	Rev 1449
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	*/	27	*/
28		28
29	#include <time.h>	29	#include <sys/time.h>
30	#include <unistd.h>	30	#include <unistd.h>
31	#include <ipc/ipc.h>	31	#include <ipc/ipc.h>
32	#include <stdio.h>	32	#include <stdio.h>
33	#include <arch/barrier.h>	33	#include <arch/barrier.h>
34		34
35	#include <sysinfo.h>	35	#include <sysinfo.h>
36	#include <as.h>	36	#include <as.h>
37	#include <ddi.h>	37	#include <ddi.h>
38		38
39	/* Pointers to public variables with time */	39	/* Pointers to public variables with time */
40	struct {	40	struct {
41	volatile sysarg_t seconds1;	41	volatile sysarg_t seconds1;
42	volatile sysarg_t useconds;	42	volatile sysarg_t useconds;
43	volatile sysarg_t seconds2;	43	volatile sysarg_t seconds2;
44	} *ktime = NULL;	44	} *ktime = NULL;
45		45
46		46
47	/** POSIX gettimeofday	47	/** POSIX gettimeofday
48	*	48	*
49	* The time variables are memory mapped(RO) from kernel, which updates	49	* The time variables are memory mapped(RO) from kernel, which updates
50	* them periodically. As it is impossible to read 2 values atomically, we	50	* them periodically. As it is impossible to read 2 values atomically, we
51	* use a trick: First read a seconds, then read microseconds, then	51	* use a trick: First read a seconds, then read microseconds, then
52	* read seconds again. If a second elapsed in the meantime, read	52	* read seconds again. If a second elapsed in the meantime, read
53	* useconds again. This provides assurance, that at least the	53	* useconds again. This provides assurance, that at least the
54	* sequence of subsequent gettimeofday calls is ordered.	54	* sequence of subsequent gettimeofday calls is ordered.
55	*/	55	*/
56	#define TMAREA (10010241024)	56	#define TMAREA (10010241024)
57	int gettimeofday(struct timeval tv, struct timezone tz)	57	int gettimeofday(struct timeval tv, struct timezone tz)
58	{	58	{
59	void *mapping;	59	void *mapping;
60	sysarg_t s1, s2;	60	sysarg_t s1, s2;
61	sysarg_t t1;	61	sysarg_t t1;
62	int res;	62	int res;
63		63
64	if (!ktime) {	64	if (!ktime) {
65	/* TODO: specify better, where to map the area */	65	/* TODO: specify better, where to map the area */
66	/* Get the mapping of kernel clock */	66	/* Get the mapping of kernel clock */
67	res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV,	67	res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV,
68	TMAREA,	68	TMAREA,
69	PAGE_SIZE,	69	PAGE_SIZE,
70	AS_AREA_READ \| AS_AREA_CACHEABLE,	70	AS_AREA_READ \| AS_AREA_CACHEABLE,
71	&t1,&t1,&t1);	71	&t1,&t1,&t1);
72	if (res) {	72	if (res) {
73	printf("Failed to initialize timeofday memarea\n");	73	printf("Failed to initialize timeofday memarea\n");
74	_exit(1);	74	_exit(1);
75	}	75	}
76	ktime = (void *) (TMAREA);	76	ktime = (void *) (TMAREA);
77	}	77	}
78	if (tz) {	78	if (tz) {
79	tz->tz_minuteswest = 0;	79	tz->tz_minuteswest = 0;
80	tz->tz_dsttime = DST_NONE;	80	tz->tz_dsttime = DST_NONE;
81	}	81	}
82		82
83	s2 = ktime->seconds2;	83	s2 = ktime->seconds2;
84	read_barrier();	84	read_barrier();
85	tv->tv_usec = ktime->useconds;	85	tv->tv_usec = ktime->useconds;
86	read_barrier();	86	read_barrier();
87	s1 = ktime->seconds1;	87	s1 = ktime->seconds1;
88	if (s1 != s2) {	88	if (s1 != s2) {
89	tv->tv_usec = 0;	89	tv->tv_usec = 0;
90	tv->tv_sec = s1 > s2 ? s1 : s2;	90	tv->tv_sec = s1 > s2 ? s1 : s2;
91	} else	91	} else
92	tv->tv_sec = s1;	92	tv->tv_sec = s1;
93		93
94	return 0;	94	return 0;
95	}	95	}
96		96

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libc/generic/time.c – Rev 1442 → 1449