grub/m4/sleep.m4
Vladimir 'phcoder' Serbinenko 053cfcddf1 Import new gnulib.
2013-04-11 21:12:46 +02:00

62 lines
2 KiB
Text

# sleep.m4 serial 7
dnl Copyright (C) 2007-2013 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])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
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 $ac_cv_have_decl_sleep != yes; then
HAVE_SLEEP=0
else
dnl Cygwin 1.5.x has a bug where sleep can't exceed 49.7 days.
AC_CACHE_CHECK([for working sleep], [gl_cv_func_sleep_works],
[AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <errno.h>
#include <unistd.h>
#include <signal.h>
static void
handle_alarm (int sig)
{
if (sig != SIGALRM)
_exit (2);
}
]], [[
/* Failure to compile this test due to missing alarm is okay,
since all such platforms (mingw) also lack sleep. */
unsigned int pentecost = 50 * 24 * 60 * 60; /* 50 days. */
unsigned int remaining;
signal (SIGALRM, handle_alarm);
alarm (1);
remaining = sleep (pentecost);
if (remaining > pentecost)
return 3;
if (remaining <= pentecost - 10)
return 4;
return 0;
]])],
[gl_cv_func_sleep_works=yes], [gl_cv_func_sleep_works=no],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu*) gl_cv_func_sleep_works="guessing yes" ;;
# If we don't know, assume the worst.
*) gl_cv_func_sleep_works="guessing no" ;;
esac
])])
case "$gl_cv_func_sleep_works" in
*yes) ;;
*)
REPLACE_SLEEP=1
;;
esac
fi
])