dnl CF_FUNC_NANOSLEEP version: 5 updated: 2017/01/21 11:06:25
dnl -----------------
dnl Check for existence of workable nanosleep() function.  Some systems, e.g.,
dnl AIX 4.x, provide a non-working version.
AC_DEFUN([CF_FUNC_NANOSLEEP],[
AC_CACHE_CHECK(if nanosleep really works,cf_cv_func_nanosleep,[
AC_TRY_RUN([
#include <stdio.h>
#include <errno.h>
#include <time.h>

#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif

int main(void) {
	struct timespec ts1, ts2;
	int code;
	ts1.tv_sec  = 0;
	ts1.tv_nsec = 750000000;
	ts2.tv_sec  = 0;
	ts2.tv_nsec = 0;
	errno = 0;
	code = nanosleep(&ts1, &ts2); /* on failure errno is ENOSYS. */
	${cf_cv_main_return:-return}(code != 0);
}
],
	[cf_cv_func_nanosleep=yes],
	[cf_cv_func_nanosleep=no],
	[cf_cv_func_nanosleep=unknown])])

test "$cf_cv_func_nanosleep" = "yes" && AC_DEFINE(HAVE_NANOSLEEP,1,[Define to 1 if we have nanosleep()])
])
