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-rw-r--r--m4/usleep.m449
1 files changed, 49 insertions, 0 deletions
diff --git a/m4/usleep.m4 b/m4/usleep.m4
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+++ b/m4/usleep.m4
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+# usleep.m4 serial 7
+dnl Copyright (C) 2009-2022 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.
+
+dnl This macro intentionally does not check for select or nanosleep;
+dnl both of those modules can require external libraries.
+AC_DEFUN([gl_FUNC_USLEEP],
+[
+ AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+ dnl usleep was required in POSIX 2001, but dropped as obsolete in
+ dnl POSIX 2008; therefore, it is not always exposed in headers.
+ AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CHECK_FUNCS_ONCE([usleep])
+ AC_CHECK_TYPE([useconds_t], [],
+ [AC_DEFINE([useconds_t], [unsigned int], [Define to an unsigned 32-bit
+ type if <sys/types.h> lacks this type.])])
+ if test $ac_cv_func_usleep = no; then
+ HAVE_USLEEP=0
+ else
+ dnl POSIX allows implementations to reject arguments larger than
+ dnl 999999, but GNU guarantees it will work.
+ AC_CACHE_CHECK([whether usleep allows large arguments],
+ [gl_cv_func_usleep_works],
+ [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <unistd.h>
+]], [[return !!usleep (1000000);]])],
+ [gl_cv_func_usleep_works=yes], [gl_cv_func_usleep_works=no],
+ [case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu* | gnu*) gl_cv_func_usleep_works="guessing yes" ;;
+ # Guess yes on musl systems.
+ *-musl*) gl_cv_func_usleep_works="guessing yes" ;;
+ # Guess no on native Windows.
+ mingw*) gl_cv_func_usleep_works="guessing no" ;;
+ # If we don't know, obey --enable-cross-guesses.
+ *) gl_cv_func_usleep_works="$gl_cross_guess_normal" ;;
+ esac
+ ])])
+ case "$gl_cv_func_usleep_works" in
+ *yes) ;;
+ *)
+ REPLACE_USLEEP=1
+ ;;
+ esac
+ fi
+])