Import glibc-mainline for 2006-08-16

git-svn-id: svn://svn.eglibc.org/fsf/trunk@4 7b3dc134-2b1b-0410-93df-9e9f96275f8d

1 files changed, 149 insertions, 0 deletions

diff --git a/libc/sysdeps/unix/sysv/linux/sleep.c b/libc/sysdeps/unix/sysv/linux/sleep.c
new file mode 100644
index 000000000..0e41a1133
--- /dev/null
+++ b/libc/sysdeps/unix/sysv/linux/sleep.c
@@ -0,0 +1,149 @@
+/* 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)