xnanosleep: Rewrite to use new dtotimespec module.

It has the conversion code that used to be in xnanosleep.
* lib/xnanosleep.c: Do not include limits.h, stdbool.h, stdio.h,
assert.h, sys/types.h, or intprops.h.  Include timespec.h instead.
(TIME_T_MAX): Remove.
(xnanosleep): Rewrite in terms of dtotimespec.
* modules/xnanosleep (Depends-on): Add dtotimespec.
Remove intprops, stdbool.

1 files changed, 3 insertions, 63 deletions

diff --git a/lib/xnanosleep.c b/lib/xnanosleep.c
index 74cb895303..442ddf5c20 100644
--- a/lib/xnanosleep.c
+++ b/lib/xnanosleep.c
@@ -22,20 +22,11 @@
 
 #include "xnanosleep.h"
 
-#include <limits.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <assert.h>
+#include <timespec.h>
+
 #include <errno.h>
-#include <sys/types.h>
 #include <time.h>
 
-#include "intprops.h"
-
-#ifndef TIME_T_MAX
-# define TIME_T_MAX TYPE_MAXIMUM (time_t)
-#endif
-
 /* Sleep until the time (call it WAKE_UP_TIME) specified as
    SECONDS seconds after the time this function is called.
    SECONDS must be non-negative.  If SECONDS is so large that
@@ -46,61 +37,10 @@
 int
 xnanosleep (double seconds)
 {
-  enum { BILLION = 1000000000 };
-
-  /* For overflow checking, use naive comparison if possible, widening
-     to long double if double is not wide enough.  Otherwise, use <=,
-     not <, to avoid problems when TIME_T_MAX is less than SECONDS but
-     compares equal to SECONDS after loss of precision when coercing
-     from time_t to long double.  This mishandles near-maximal values
-     in some rare (perhaps theoretical) cases but that is better than
-     undefined behavior.  */
-  bool overflow = ((time_t) ((double) TIME_T_MAX / 2) == TIME_T_MAX / 2
-                   ? TIME_T_MAX < seconds
-                   : (time_t) ((long double) TIME_T_MAX / 2) == TIME_T_MAX / 2
-                   ? TIME_T_MAX < (long double) seconds
-                   : TIME_T_MAX <= (long double) seconds);
-
-  struct timespec ts_sleep;
-
-  assert (0 <= seconds);
-
-  /* Separate whole seconds from nanoseconds.  */
-  if (! overflow)
-    {
-      time_t floor_seconds = seconds;
-      double ns = BILLION * (seconds - floor_seconds);
-      ts_sleep.tv_sec = floor_seconds;
-
-      /* Round up to the next whole number, if necessary, so that we
-         always sleep for at least the requested amount of time.  Assuming
-         the default rounding mode, we don't have to worry about the
-         rounding error when computing 'ns' above, since the error won't
-         cause 'ns' to drop below an integer boundary.  */
-      ts_sleep.tv_nsec = ns;
-      ts_sleep.tv_nsec += (ts_sleep.tv_nsec < ns);
-
-      /* Normalize the interval length.  nanosleep requires this.  */
-      if (BILLION <= ts_sleep.tv_nsec)
-        {
-          if (ts_sleep.tv_sec == TIME_T_MAX)
-            overflow = true;
-          else
-            {
-              ts_sleep.tv_sec++;
-              ts_sleep.tv_nsec -= BILLION;
-            }
-        }
-    }
+  struct timespec ts_sleep = dtotimespec (seconds);
 
   for (;;)
     {
-      if (overflow)
-        {
-          ts_sleep.tv_sec = TIME_T_MAX;
-          ts_sleep.tv_nsec = BILLION - 1;
-        }
-
       /* Linux-2.6.8.1's nanosleep returns -1, but doesn't set errno
          when resumed after being suspended.  Earlier versions would
          set errno to EINTR.  nanosleep from linux-2.6.10, as well as