# sleep.m4 serial 3

dnl Copyright (C) 2007-2010 Free Software Foundation, Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_SLEEP],

[

AC_REQUIRE([gl_UNISTD_H_DEFAULTS])

dnl We expect to see the declaration of sleep() in a header file.

dnl Older versions of mingw have a sleep() function that is an alias to

dnl _sleep() in MSVCRT. It has a different signature than POSIX sleep():

dnl it takes the number of milliseconds as argument and returns void.

dnl mingw does not declare this function.

AC_CHECK_DECLS([sleep], , , [#include <unistd.h>])

AC_CHECK_FUNCS_ONCE([sleep])

if test $ac_cv_have_decl_sleep != yes; then

HAVE_SLEEP=0

AC_LIBOBJ([sleep])

else

dnl Cygwin 1.5.x has a bug where sleep can't exceed 49.7 days.

AC_CACHE_CHECK([for working sleep], [gl_cv_func_sleep_works],

[AC_RUN_IFELSE([AC_LANG_PROGRAM([[

#include <errno.h>

#include <unistd.h>

#include <signal.h>

static void

handle_alarm (int sig)

{

if (sig != SIGALRM)

_exit (2);

}

]], [[

/* Failure to compile this test due to missing alarm is okay,

since all such platforms (mingw) also lack sleep. */

unsigned int pentecost = 50 * 24 * 60 * 60; /* 50 days. */

unsigned int remaining;

signal (SIGALRM, handle_alarm);

alarm (1);

remaining = sleep (pentecost);

return !(pentecost - 10 < remaining && remaining <= pentecost);]])],

[gl_cv_func_sleep_works=yes], [gl_cv_func_sleep_works=no],

[gl_cv_func_sleep_works="guessing no"])])

if test "$gl_cv_func_sleep_works" != yes; then

REPLACE_SLEEP=1

AC_LIBOBJ([sleep])

fi

fi

])