1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)usleep.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/time.h>
#include <signal.h>
#include <unistd.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
#else
#define TICK 10000 /* system clock resolution in microseconds */
#define USPS 1000000 /* number of microseconds in a second */
#define setvec(vec, a) \
vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0
static int ringring;
#endif
void
usleep(useconds)
unsigned int useconds;
{
#ifdef _THREAD_SAFE
struct timespec time_to_sleep;
if (useconds) {
time_to_sleep.ts_nsec = (useconds % 1000000) * 1000;
time_to_sleep.ts_sec = useconds / 1000000;
nanosleep(&time_to_sleep,NULL);
}
#else
register struct itimerval *itp;
struct itimerval itv, oitv;
struct sigvec vec, ovec;
long omask;
static void sleephandler();
itp = &itv;
if (!useconds)
return;
timerclear(&itp->it_interval);
timerclear(&itp->it_value);
if (setitimer(ITIMER_REAL, itp, &oitv) < 0)
return;
itp->it_value.tv_sec = useconds / USPS;
itp->it_value.tv_usec = useconds % USPS;
if (timerisset(&oitv.it_value)) {
if (timercmp(&oitv.it_value, &itp->it_value, >)) {
oitv.it_value.tv_sec -= itp->it_value.tv_sec;
oitv.it_value.tv_usec -= itp->it_value.tv_usec;
if (oitv.it_value.tv_usec < 0) {
oitv.it_value.tv_usec += USPS;
oitv.it_value.tv_sec--;
}
} else {
itp->it_value = oitv.it_value;
oitv.it_value.tv_sec = 0;
oitv.it_value.tv_usec = 2 * TICK;
}
}
setvec(vec, sleephandler);
(void) sigvec(SIGALRM, &vec, &ovec);
omask = sigblock(sigmask(SIGALRM));
ringring = 0;
(void) setitimer(ITIMER_REAL, itp, (struct itimerval *)0);
while (!ringring)
sigpause(omask &~ sigmask(SIGALRM));
(void) sigvec(SIGALRM, &ovec, (struct sigvec *)0);
(void) sigsetmask(omask);
(void) setitimer(ITIMER_REAL, &oitv, (struct itimerval *)0);
#endif
}
#ifndef _THREAD_SAFE
static void
sleephandler()
{
ringring = 1;
}
#endif
|
