X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fnanosleep.c;h=7a7cc02fd987c9cf8d77ec0f0533b11b6ce80c20;hb=26c5fd742f9136e2ddbd4695a9172c3fa30ea260;hp=26562662bf26fbd1b568941a577376b79cf8ee1f;hpb=7994372d6e3d595435a3d834eabe46a9a72ab665;p=gnulib.git

diff --git a/lib/nanosleep.c b/lib/nanosleep.c
index 26562662b..7a7cc02fd 100644
--- a/lib/nanosleep.c
+++ b/lib/nanosleep.c
@@ -1,10 +1,12 @@
 /* Provide a replacement for the POSIX nanosleep function.
-   Copyright (C) 1999, 2000 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   Copyright (C) 1999, 2000, 2002, 2004, 2005, 2006, 2007, 2008 Free
+   Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -12,34 +14,96 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* written by Jim Meyering */
 
 #include <config.h>
 
-/* Undefine nanosleep here so any prototype is not redefined to be a
-   prototype for rpl_nanosleep. (they'd conflict e.g., on alpha-dec-osf3.2)  */
-#undef nanosleep
+#include <time.h>
+
+#include "sig-handler.h"
+#include "timespec.h"
 
+#include <stdbool.h>
 #include <stdio.h>
 #include <sys/types.h>
+#include <sys/select.h>
 #include <signal.h>
 
+#include <sys/time.h>
 #include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
 
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
+#include <unistd.h>
+
+#undef nanosleep
+
+enum { BILLION = 1000 * 1000 * 1000 };
+
+#if HAVE_BUG_BIG_NANOSLEEP
+
+static void
+getnow (struct timespec *t)
+{
+# if defined CLOCK_MONOTONIC && HAVE_CLOCK_GETTIME
+  if (clock_gettime (CLOCK_MONOTONIC, t) == 0)
+    return;
+# endif
+  gettime (t);
+}
+
+int
+rpl_nanosleep (const struct timespec *requested_delay,
+	       struct timespec *remaining_delay)
+{
+  /* nanosleep mishandles large sleeps due to internal overflow
+     problems, so check that the proper amount of time has actually
+     elapsed.  */
 
-#include "nanosleep.h"
+  struct timespec delay = *requested_delay;
+  struct timespec t0;
+  getnow (&t0);
 
-static int suspended;
-int first_call = 1;
+  for (;;)
+    {
+      int r = nanosleep (&delay, remaining_delay);
+      if (r == 0)
+	{
+	  time_t secs_sofar;
+	  struct timespec now;
+	  getnow (&now);
+
+	  secs_sofar = now.tv_sec - t0.tv_sec;
+	  if (requested_delay->tv_sec < secs_sofar)
+	    return 0;
+	  delay.tv_sec = requested_delay->tv_sec - secs_sofar;
+	  delay.tv_nsec = requested_delay->tv_nsec - (now.tv_nsec - t0.tv_nsec);
+	  if (delay.tv_nsec < 0)
+	    {
+	      if (delay.tv_sec == 0)
+		return 0;
+	      delay.tv_nsec += BILLION;
+	      delay.tv_sec--;
+	    }
+	  else if (BILLION <= delay.tv_nsec)
+	    {
+	      delay.tv_nsec -= BILLION;
+	      delay.tv_sec++;
+	    }
+	}
+    }
+}
+
+#else
+
+/* Some systems (MSDOS) don't have SIGCONT.
+   Using SIGTERM here turns the signal-handling code below
+   into a no-op on such systems. */
+# ifndef SIGCONT
+#  define SIGCONT SIGTERM
+# endif
+
+static sig_atomic_t volatile suspended;
 
 /* Handle SIGCONT. */
 
@@ -49,47 +113,57 @@ sighandler (int sig)
   suspended = 1;
 }
 
-/* FIXME: comment */
+/* Suspend execution for at least *TS_DELAY seconds.  */
 
 static void
 my_usleep (const struct timespec *ts_delay)
 {
   struct timeval tv_delay;
   tv_delay.tv_sec = ts_delay->tv_sec;
-  tv_delay.tv_usec = ts_delay->tv_nsec / 1000;
-  select (0, (void *) 0, (void *) 0, (void *) 0, &tv_delay);
+  tv_delay.tv_usec = (ts_delay->tv_nsec + 999) / 1000;
+  if (tv_delay.tv_usec == 1000000)
+    {
+      time_t t1 = tv_delay.tv_sec + 1;
+      if (t1 < tv_delay.tv_sec)
+	tv_delay.tv_usec = 1000000 - 1; /* close enough */
+      else
+	{
+	  tv_delay.tv_sec = t1;
+	  tv_delay.tv_usec = 0;
+	}
+    }
+  select (0, NULL, NULL, NULL, &tv_delay);
 }
 
-/* FIXME: comment */
+/* Suspend execution for at least *REQUESTED_DELAY seconds.  The
+   *REMAINING_DELAY part isn't implemented yet.  */
 
 int
 rpl_nanosleep (const struct timespec *requested_delay,
-	   struct timespec *remaining_delay)
+	       struct timespec *remaining_delay)
 {
-#ifdef SA_NOCLDSTOP
-  struct sigaction oldact, newact;
-#endif
-
-  suspended = 0;
+  static bool initialized;
 
   /* set up sig handler */
-  if (first_call)
+  if (! initialized)
     {
-#ifdef SA_NOCLDSTOP
-      newact.sa_handler = sighandler;
-      sigemptyset (&newact.sa_mask);
-      newact.sa_flags = 0;
+      struct sigaction oldact;
 
       sigaction (SIGCONT, NULL, &oldact);
-      if (oldact.sa_handler != SIG_IGN)
-	sigaction (SIGCONT, &newact, NULL);
-#else
-      if (signal (SIGCONT, SIG_IGN) != SIG_IGN)
-	signal (SIGCONT, sighandler);
-#endif
-      first_call = 0;
+      if (get_handler (&oldact) != SIG_IGN)
+	{
+	  struct sigaction newact;
+
+	  newact.sa_handler = sighandler;
+	  sigemptyset (&newact.sa_mask);
+	  newact.sa_flags = 0;
+	  sigaction (SIGCONT, &newact, NULL);
+	}
+      initialized = true;
     }
 
+  suspended = 0;
+
   my_usleep (requested_delay);
 
   if (suspended)
@@ -105,3 +179,4 @@ rpl_nanosleep (const struct timespec *requested_delay,
 
   return suspended;
 }
+#endif