-mautoupdate

[gnulib.git] / lib / nanosleep.c

diff --git a/lib/nanosleep.c b/lib/nanosleep.c
index 7a7cc02..58fc788 100644 (file)
--- a/lib/nanosleep.c
+++ b/lib/nanosleep.c
@@ -1,7 +1,6 @@
 /* Provide a replacement for the POSIX nanosleep function.
 
-   Copyright (C) 1999, 2000, 2002, 2004, 2005, 2006, 2007, 2008 Free
-   Software Foundation, Inc.
+   Copyright (C) 1999-2000, 2002, 2004-2010 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
@@ -22,8 +21,9 @@
 
 #include <time.h>
 
+#include "intprops.h"
 #include "sig-handler.h"
-#include "timespec.h"
+#include "verify.h"
 
 #include <stdbool.h>
 #include <stdio.h>
@@ -42,56 +42,45 @@ 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)
+               struct timespec *remaining_delay)
 {
   /* nanosleep mishandles large sleeps due to internal overflow
-     problems, so check that the proper amount of time has actually
-     elapsed.  */
-
-  struct timespec delay = *requested_delay;
-  struct timespec t0;
-  getnow (&t0);
-
-  for (;;)
+     problems.  The worst known case of this is cygwin 1.5.x, which
+     can't sleep more than 49.7 days (2**32 milliseconds).  Solve this
+     by breaking the sleep up into smaller chunks.  Verify that time_t
+     is large enough.  */
+  verify (TYPE_MAXIMUM (time_t) / 49 / 24 / 60 / 60);
+  const time_t limit = 49 * 24 * 60 * 60;
+  time_t seconds = requested_delay->tv_sec;
+  struct timespec intermediate;
+  intermediate.tv_nsec = 0;
+
+  while (limit < seconds)
     {
-      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++;
-           }
-       }
+      int result;
+      intermediate.tv_sec = limit;
+      result = nanosleep (&intermediate, remaining_delay);
+      seconds -= limit;
+      if (result)
+        {
+          if (remaining_delay)
+            {
+              remaining_delay->tv_sec += seconds;
+              remaining_delay->tv_nsec += requested_delay->tv_nsec;
+              if (BILLION <= requested_delay->tv_nsec)
+                {
+                  remaining_delay->tv_sec++;
+                  remaining_delay->tv_nsec -= BILLION;
+                }
+            }
+          return result;
+        }
     }
+  intermediate.tv_sec = seconds;
+  intermediate.tv_nsec = requested_delay->tv_nsec;
+  return nanosleep (&intermediate, remaining_delay);
 }
 
 #else
@@ -125,12 +114,12 @@ my_usleep (const struct timespec *ts_delay)
     {
       time_t t1 = tv_delay.tv_sec + 1;
       if (t1 < tv_delay.tv_sec)
-       tv_delay.tv_usec = 1000000 - 1; /* close enough */
+        tv_delay.tv_usec = 1000000 - 1; /* close enough */
       else
-       {
-         tv_delay.tv_sec = t1;
-         tv_delay.tv_usec = 0;
-       }
+        {
+          tv_delay.tv_sec = t1;
+          tv_delay.tv_usec = 0;
+        }
     }
   select (0, NULL, NULL, NULL, &tv_delay);
 }
@@ -140,10 +129,16 @@ my_usleep (const struct timespec *ts_delay)
 
 int
 rpl_nanosleep (const struct timespec *requested_delay,
-              struct timespec *remaining_delay)
+               struct timespec *remaining_delay)
 {
   static bool initialized;
 
+  if (requested_delay->tv_nsec < 0 || BILLION <= requested_delay->tv_nsec)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
   /* set up sig handler */
   if (! initialized)
     {
@@ -151,14 +146,14 @@ rpl_nanosleep (const struct timespec *requested_delay,
 
       sigaction (SIGCONT, NULL, &oldact);
       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);
-       }
+        {
+          struct sigaction newact;
+
+          newact.sa_handler = sighandler;
+          sigemptyset (&newact.sa_mask);
+          newact.sa_flags = 0;
+          sigaction (SIGCONT, &newact, NULL);
+        }
       initialized = true;
     }
 
@@ -170,7 +165,7 @@ rpl_nanosleep (const struct timespec *requested_delay,
     {
       /* Calculate time remaining.  */
       /* FIXME: the code in sleep doesn't use this, so there's no
-        rush to implement it.  */
+         rush to implement it.  */
 
       errno = EINTR;
     }