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
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/* Implementation of the POSIX sleep function using nanosleep.
Copyright (C) 1996,1997,1998,1999,2003,2005 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <time.h>
#include <signal.h>
#include <string.h> /* For the real memset prototype. */
#include <unistd.h>
#include <sys/param.h>
#if 0
static void
cl (void *arg)
{
(void) __sigprocmask (SIG_SETMASK, arg, (sigset_t *) NULL);
}
#endif
/* We are going to use the `nanosleep' syscall of the kernel. But the
kernel does not implement the stupid SysV SIGCHLD vs. SIG_IGN
behaviour for this syscall. Therefore we have to emulate it here. */
unsigned int
__sleep (unsigned int seconds)
{
const unsigned int max
= (unsigned int) (((unsigned long int) (~((time_t) 0))) >> 1);
struct timespec ts;
sigset_t set, oset;
unsigned int result;
/* This is not necessary but some buggy programs depend on this. */
if (__builtin_expect (seconds == 0, 0))
{
#ifdef CANCELLATION_P
CANCELLATION_P (THREAD_SELF);
#endif
return 0;
}
ts.tv_sec = 0;
ts.tv_nsec = 0;
again:
if (sizeof (ts.tv_sec) <= sizeof (seconds))
{
/* Since SECONDS is unsigned assigning the value to .tv_sec can
overflow it. In this case we have to wait in steps. */
ts.tv_sec += MIN (seconds, max);
seconds -= (unsigned int) ts.tv_sec;
}
else
{
ts.tv_sec = (time_t) seconds;
seconds = 0;
}
/* Linux will wake up the system call, nanosleep, when SIGCHLD
arrives even if SIGCHLD is ignored. We have to deal with it
in libc. We block SIGCHLD first. */
__sigemptyset (&set);
__sigaddset (&set, SIGCHLD);
if (__sigprocmask (SIG_BLOCK, &set, &oset))
return -1;
/* If SIGCHLD is already blocked, we don't have to do anything. */
if (!__sigismember (&oset, SIGCHLD))
{
int saved_errno;
struct sigaction oact;
__sigemptyset (&set);
__sigaddset (&set, SIGCHLD);
/* We get the signal handler for SIGCHLD. */
if (__sigaction (SIGCHLD, (struct sigaction *) NULL, &oact) < 0)
{
saved_errno = errno;
/* Restore the original signal mask. */
(void) __sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
__set_errno (saved_errno);
return -1;
}
/* Note the sleep() is a cancellation point. But since we call
nanosleep() which itself is a cancellation point we do not
have to do anything here. */
if (oact.sa_handler == SIG_IGN)
{
//__libc_cleanup_push (cl, &oset);
/* We should leave SIGCHLD blocked. */
while (1)
{
result = __nanosleep (&ts, &ts);
if (result != 0 || seconds == 0)
break;
if (sizeof (ts.tv_sec) <= sizeof (seconds))
{
ts.tv_sec = MIN (seconds, max);
seconds -= (unsigned int) ts.tv_nsec;
}
}
//__libc_cleanup_pop (0);
saved_errno = errno;
/* Restore the original signal mask. */
(void) __sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
__set_errno (saved_errno);
goto out;
}
/* We should unblock SIGCHLD. Restore the original signal mask. */
(void) __sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
}
result = __nanosleep (&ts, &ts);
if (result == 0 && seconds != 0)
goto again;
out:
if (result != 0)
/* Round remaining time. */
result = seconds + (unsigned int) ts.tv_sec + (ts.tv_nsec >= 500000000L);
return result;
}
weak_alias (__sleep, sleep)
|
