dnl check for vprintf/vsprintf() which are GNU extensions
AC_FUNC_VPRINTF
dnl check for vsnprintf() which is another GNU extension
-AC_CHECK_FUNC(vsnprintf, AC_DEFINE(HAVE_VSNPRINTF))
+AC_CHECK_FUNCS(vsnprintf)
+
+dnl check for usleep() and nanosleep() which is better in MT programs
+AC_CHECK_FUNCS(nanosleep,
+ AC_DEFINE(HAVE_NANOSLEEP),
+ [AC_CHECK_LIB(posix4, nanosleep, AC_DEFINE(HAVE_NANOSLEEP))])
+AC_CHECK_FUNCS(usleep)
AC_LANG_SAVE
AC_LANG_CPLUSPLUS