1 /* Provide a replacement for the POSIX nanosleep function.
2 Copyright (C) 1999, 2000, 2002, 2004, 2005 Free Software Foundation, Inc.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
7 any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
17 #include <sys/cdefs.h>
18 __RCSID("$NetBSD: nanosleep.c,v 1.2 2016/05/17 14:00:09 christos Exp $");
19
20
21 /* written by Jim Meyering */
22
23 #ifdef HAVE_CONFIG_H
24 # include <config.h>
25 #endif
26
27 /* Undefine nanosleep here so any prototype is not redefined to be a
28 prototype for rpl_nanosleep. (they'd conflict e.g., on alpha-dec-osf3.2) */
29 #undef nanosleep
30
31 #include <stdbool.h>
32 #include <stdio.h>
33 #include <sys/types.h>
34 #include <signal.h>
35
36 #include <errno.h>
37
38 #if HAVE_UNISTD_H
39 # include <unistd.h>
40 #endif
41
42 #include "timespec.h"
43
44 /* Some systems (MSDOS) don't have SIGCONT.
45 Using SIGTERM here turns the signal-handling code below
46 into a no-op on such systems. */
47 #ifndef SIGCONT
48 # define SIGCONT SIGTERM
49 #endif
50
51 #if ! HAVE_SIGINTERRUPT
52 # define siginterrupt(sig, flag) /* empty */
53 #endif
54
55 static sig_atomic_t volatile suspended;
56
57 /* Handle SIGCONT. */
58
59 static void
sighandler(int sig)60 sighandler (int sig)
61 {
62 suspended = 1;
63 }
64
65 /* FIXME: comment */
66
67 static void
my_usleep(const struct timespec * ts_delay)68 my_usleep (const struct timespec *ts_delay)
69 {
70 struct timeval tv_delay;
71 tv_delay.tv_sec = ts_delay->tv_sec;
72 tv_delay.tv_usec = (ts_delay->tv_nsec + 999) / 1000;
73 if (tv_delay.tv_usec == 1000000)
74 {
75 tv_delay.tv_sec++;
76 tv_delay.tv_usec = 0;
77 }
78 select (0, NULL, NULL, NULL, &tv_delay);
79 }
80
81 /* FIXME: comment */
82
83 int
rpl_nanosleep(const struct timespec * requested_delay,struct timespec * remaining_delay)84 rpl_nanosleep (const struct timespec *requested_delay,
85 struct timespec *remaining_delay)
86 {
87 static bool initialized;
88
89 /* set up sig handler */
90 if (! initialized)
91 {
92 #ifdef SA_NOCLDSTOP
93 struct sigaction oldact, newact;
94 newact.sa_handler = sighandler;
95 sigemptyset (&newact.sa_mask);
96 newact.sa_flags = 0;
97
98 sigaction (SIGCONT, NULL, &oldact);
99 if (oldact.sa_handler != SIG_IGN)
100 sigaction (SIGCONT, &newact, NULL);
101 #else
102 if (signal (SIGCONT, SIG_IGN) != SIG_IGN)
103 {
104 signal (SIGCONT, sighandler);
105 siginterrupt (SIGCONT, 1);
106 }
107 #endif
108 initialized = true;
109 }
110
111 suspended = 0;
112
113 my_usleep (requested_delay);
114
115 if (suspended)
116 {
117 /* Calculate time remaining. */
118 /* FIXME: the code in sleep doesn't use this, so there's no
119 rush to implement it. */
120
121 errno = EINTR;
122 }
123
124 /* FIXME: Restore sig handler? */
125
126 return suspended;
127 }
128