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authorUlrich Drepper <drepper@redhat.com>1998-11-17 20:39:52 +0000
committerUlrich Drepper <drepper@redhat.com>1998-11-17 20:39:52 +0000
commit45a9a50e68f58102e86b949527fd0c2bc0abf4ce (patch)
tree13b0b8386ad948982bb67bfe3f09e62e91f203b9 /sysdeps
parentd8cceb4fcf42c9dd7805b75a8640e15d00dd7ac9 (diff)
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Update.
* sysdeps/unix/sysv/linux/sleep.c (__sleep): Make Unix98 compliant by working removing SIG_IGN handler for SIGCHLD if necessary. Patch by H.J. Lu <hjl@lucon.org>.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/unix/sysv/linux/sleep.c54
1 files changed, 51 insertions, 3 deletions
diff --git a/sysdeps/unix/sysv/linux/sleep.c b/sysdeps/unix/sysv/linux/sleep.c
index f67403f694..5fb11603cf 100644
--- a/sysdeps/unix/sysv/linux/sleep.c
+++ b/sysdeps/unix/sysv/linux/sleep.c
@@ -1,5 +1,5 @@
/* Implementation of the POSIX sleep function using nanosleep.
- Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+ Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
@@ -18,18 +18,66 @@
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>
+/* 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 timespec ts = { tv_sec: (long int) seconds, tv_nsec: 0 };
+ sigset_t set, oset;
+ struct sigaction oact;
unsigned int result;
- if (__nanosleep (&ts, &ts) == 0)
- result = 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;
+
+ /* 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);