xnanosleep.c

Tag

Show log
Commit

Hash : 3ac95524
Author :
Date : 2007-02-12T18:49:19

New module 'time', so that apps can include <time.h> as per
POSIX and GNU instead of separate include files like time_r.h
and timegm.h.  This implementation tries out a simpler approach
for replacing decls in standard include files (as compared to
the string module), somewhat as an experiment.

* config/srclist.txt: Comment out mktime.c for now.
* doc/gnulib-tool.texi (Initial import): Don't use time_r as an example
since it doesn't apply any more.  Use generic wording instead.
* MODULES.html.sh (Support for systems lacking POSIX:2001): New module
'time'.
* lib/time_.h, m4/time_h.m4, modules/time: New files.
* lib/strptime.h, lib/time_r.h, lib/timegm.h: Remove.
* lib/mktime.c: Include config.h depending on _LIBC, not HAVE_CONFIG_H.
Don't include <sys/types.h>; no longer needed since we assume C89.
* lib/mktime.c: Don't include "time_r.h"; no longer needed.
* lib/strftime.c: Likewise.
* lib/time_r.c: Likewise.
* lib/nanosleep.c (nanosleep): #undef after include files, not before.
* lib/nanosleep.c: Include <time.h> first, to check interface.
* lib/strptime.c: Likewise.
* lib/time_r.c: Likewise.
* lib/timegm.c: Likewise.
* lib/strptime.c: Don't include strptime.h or time_r.h; no longer
needed.
* lib/timegm.c: Don't include timegm.h; no longer needed.
* lib/timespec.h: Don't include <sys/time.h> before <time.h>;
time.h now handles any problems in that area.
(struct timespec, nanosleep): Remove; time.h now arranges for these.
* lib/xnanosleep.c: Don't include timespec.h; no longer needed now
that time.h defines struct timespec.
* m4/nanosleep.m4 (gl_FUNC_NANOSLEEP): Check that nanosleep is declared.
Set REPLACE_NANOSLEEP.  Don't AC_DEFINE nanosleep; the time module now
handles that.
* m4/strptime.m4 (gl_FUNC_STPRTIME): Set REPLACE_STRPTIME.
* m4/time_r.m4 (gl_TIME_R): Don't define HAVE_TIME_R_POSIX; no longer
needed.  Set REPLACE_LOCALTIME.
* m4/timegm.m4 (gl_FUNC_TIMEGM): Set REPLACE_TIMEGM.
* m4/timespec.m4 (gl_CHECK_TYPE_STRUCT_TIMESPEC): Move to time_h.m4.
(gl_TIMESPEC): Don't check for sys/time.h or struct timespec or
nanosleep; time_h.m4 now does that.  Don't require
gl_USE_SYSTEM_EXTENSIONS; no longer needed directly, and the time
module handles this now.
* modules/getdate (Depends-on): Remove timespec.  Add time.
* modules/nanosleep (Depends-on): Likewise.
* modules/stat-time (Depends-on): Likewise.
* modules/nanosleep (Include): Include time.h, not timespec.h.
* modules/strptime (Files): Remove lib/strptime.h.
(Depends-on): Add extensions, time.
(Include): Include time.h, not strptime.h.
* modules/time_r (Files): Remove lib/time_r.h.
(Depends-on): Add time.
(Include): Include time.h, not time_r.h.
* modules/timegm: Likewise.
* modules/timespec (Description): Now does timespec-related decls
of our own, instead of struct timespec itself.
(Depends-on): Add time; remove extensions.
(Maintainer): Add self.
* modules/utimecmp (Depends-on): Add time; remove timespec.
* modules/utimens (Depends-on): Likewise.
* modules/xnanosleep (Depends-on): Likewise.

Download

lib/xnanosleep.c

/* xnanosleep.c -- a more convenient interface to nanosleep

   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 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.

   This program 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 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

/* Mostly written (for sleep.c) by Paul Eggert.
   Factored out (creating this file) by Jim Meyering.  */

#include <config.h>

#include "xnanosleep.h"

#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <assert.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
   it is not representable as a `struct timespec', then use
   the maximum value for that interval.  Return -1 on failure
   (setting errno), 0 on success.  */

int
xnanosleep (double seconds)
{
  enum { BILLION = 1000000000 };

  bool overflow = false;
  double ns;
  struct timespec ts_sleep;

  assert (0 <= seconds);

  /* Separate whole seconds from nanoseconds.
     Be careful to detect any overflow.  */
  ts_sleep.tv_sec = seconds;
  ns = BILLION * (seconds - ts_sleep.tv_sec);
  overflow |= ! (ts_sleep.tv_sec <= seconds && 0 <= ns && ns <= BILLION);
  ts_sleep.tv_nsec = ns;

  /* 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 += (ts_sleep.tv_nsec < ns);

  /* Normalize the interval length.  nanosleep requires this.  */
  if (BILLION <= ts_sleep.tv_nsec)
    {
      time_t t = ts_sleep.tv_sec + 1;

      /* Detect integer overflow.  */
      overflow |= (t < ts_sleep.tv_sec);

      ts_sleep.tv_sec = t;
      ts_sleep.tv_nsec -= BILLION;
    }

  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
	 implementations by (all?) other vendors, doesn't return -1
	 in that case;  either it continues sleeping (if time remains)
	 or it returns zero (if the wake-up time has passed).  */
      errno = 0;
      if (nanosleep (&ts_sleep, NULL) == 0)
	break;
      if (errno != EINTR && errno != 0)
	return -1;
    }

  return 0;
}

Download

kc3-lang/gnulib/lib/xnanosleep.c

Commit

lib/xnanosleep.c