+/* Implementation of the POSIX sleep function using nanosleep.
+ Copyright (C) 1996, 1997, 1998, 1999 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 Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
-#include <sys/time.h>
-#include <sys/types.h>
+ 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. 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 <unistd.h>
-void usleep(unsigned int usec)
-{
- struct timeval tv;
+libc_hidden_proto(sleep)
+
+libc_hidden_proto(sigaction)
+libc_hidden_proto(sigprocmask)
+//libc_hidden_proto(__sigaddset)
+//libc_hidden_proto(__sigemptyset)
+//libc_hidden_proto(__sigismember)
+libc_hidden_proto(nanosleep)
- tv.tv_sec = usec / 1000000;
- tv.tv_usec = usec % 1000000;
- select(0, 0, 0, 0, &tv);
+#if 0
+/* This is a quick and dirty, but not 100% compliant with
+ * the stupid SysV SIGCHLD vs. SIG_IGN behaviour. It is
+ * fine unless you are messing with SIGCHLD... */
+unsigned int sleep (unsigned int sec)
+{
+ unsigned int res;
+ struct timespec ts = { .tv_sec = (long int) seconds, .tv_nsec = 0 };
+ res = nanosleep(&ts, &ts);
+ if (res) res = (unsigned int) ts.tv_sec + (ts.tv_nsec >= 500000000L);
+ return res;
}
-unsigned int sleep(unsigned int sec)
+#else
+
+/* We are going to use the `nanosleep' syscall of the kernel. But the
+ kernel does not implement the sstupid SysV SIGCHLD vs. SIG_IGN
+ behaviour for this syscall. Therefore we have to emulate it here. */
+unsigned int sleep (unsigned int seconds)
{
- struct timeval tv;
+ struct timespec ts = { .tv_sec = (long int) seconds, .tv_nsec = 0 };
+ sigset_t set, oset;
+ unsigned int result;
+
+ /* This is not necessary but some buggy programs depend on this. */
+ if (seconds == 0)
+ return 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. */
+ if (__sigemptyset (&set) < 0
+ || __sigaddset (&set, SIGCHLD) < 0
+ || 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;
+
+ if (__sigemptyset (&set) < 0 || __sigaddset (&set, SIGCHLD) < 0)
+ return -1;
+
+ /* 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;
+ }
+
+ if (oact.sa_handler == SIG_IGN)
+ {
+ /* We should leave SIGCHLD blocked. */
+ result = nanosleep (&ts, &ts);
+
+ saved_errno = errno;
+ /* Restore the original signal mask. */
+ (void) sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
+ __set_errno (saved_errno);
+ }
+ else
+ {
+ /* We should unblock SIGCHLD. Restore the original signal mask. */
+ (void) sigprocmask (SIG_SETMASK, &oset, (sigset_t *) NULL);
+ result = nanosleep (&ts, &ts);
+ }
+ }
+ else
+ result = nanosleep (&ts, &ts);
+
+ if (result != 0)
+ /* Round remaining time. */
+ result = (unsigned int) ts.tv_sec + (ts.tv_nsec >= 500000000L);
- tv.tv_sec = sec;
- tv.tv_usec = 0;
- select(0, 0, 0, 0, &tv);
- return tv.tv_sec;
+ return result;
}
+#endif
+libc_hidden_def(sleep)
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