1  /* Pausing execution of the current thread.
       2     Copyright (C) 2007, 2009-2021 Free Software Foundation, Inc.
       3     Written by Bruno Haible <bruno@clisp.org>, 2007.
       4  
       5     This program is free software: you can redistribute it and/or modify
       6     it under the terms of the GNU General Public License as published by
       7     the Free Software Foundation; either version 3 of the License, or
       8     (at your option) any later version.
       9  
      10     This program is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      13     GNU General Public License for more details.
      14  
      15     You should have received a copy of the GNU General Public License
      16     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <config.h>
      19  
      20  /* Specification.  */
      21  #include <unistd.h>
      22  
      23  #include <limits.h>
      24  
      25  #include "verify.h"
      26  
      27  #if defined _WIN32 && ! defined __CYGWIN__
      28  
      29  # define WIN32_LEAN_AND_MEAN  /* avoid including junk */
      30  # include <windows.h>
      31  
      32  unsigned int
      33  sleep (unsigned int seconds)
      34  {
      35    unsigned int remaining;
      36  
      37    /* Sleep for 1 second many times, because
      38         1. Sleep is not interruptible by Ctrl-C,
      39         2. we want to avoid arithmetic overflow while multiplying with 1000.  */
      40    for (remaining = seconds; remaining > 0; remaining--)
      41      Sleep (1000);
      42  
      43    return remaining;
      44  }
      45  
      46  #elif HAVE_SLEEP
      47  
      48  # undef sleep
      49  
      50  /* Guarantee unlimited sleep and a reasonable return value.  Cygwin
      51     1.5.x rejects attempts to sleep more than 49.7 days (2**32
      52     milliseconds), but uses uninitialized memory which results in a
      53     garbage answer.  Similarly, Linux 2.6.9 with glibc 2.3.4 has a too
      54     small return value when asked to sleep more than 24.85 days.  */
      55  unsigned int
      56  rpl_sleep (unsigned int seconds)
      57  {
      58    /* This requires int larger than 16 bits.  */
      59    verify (UINT_MAX / 24 / 24 / 60 / 60);
      60    const unsigned int limit = 24 * 24 * 60 * 60;
      61    while (limit < seconds)
      62      {
      63        unsigned int result;
      64        seconds -= limit;
      65        result = sleep (limit);
      66        if (result)
      67          return seconds + result;
      68      }
      69    return sleep (seconds);
      70  }
      71  
      72  #else /* !HAVE_SLEEP */
      73  
      74   #error "Please port gnulib sleep.c to your platform, possibly using usleep() or select(), then report this to bug-gnulib."
      75  
      76  #endif