2 dnl Copyright (C) 2009-2011 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 dnl This macro intentionally does not check for select or nanosleep;
8 dnl both of those modules can require external libraries.
9 AC_DEFUN([gl_FUNC_USLEEP],
11 AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
12 dnl usleep was required in POSIX 2001, but dropped as obsolete in
13 dnl POSIX 2008; therefore, it is not always exposed in headers.
14 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
15 AC_CHECK_FUNCS_ONCE([usleep])
16 AC_CHECK_TYPE([useconds_t], [],
17 [AC_DEFINE([useconds_t], [unsigned int], [Define to an unsigned 32-bit
18 type if <sys/types.h> lacks this type.])])
19 if test $ac_cv_func_usleep = no; then
23 dnl POSIX allows implementations to reject arguments larger than
24 dnl 999999, but GNU guarantees it will work.
25 AC_CACHE_CHECK([whether usleep allows large arguments],
26 [gl_cv_func_usleep_works],
27 [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
29 ]], [[return !!usleep (1000000);]])],
30 [gl_cv_func_usleep_works=yes], [gl_cv_func_usleep_works=no],
31 [gl_cv_func_usleep_works="guessing no"])])
32 if test "$gl_cv_func_usleep_works" != yes; then