Make TIM_sleep() use nanosleep(2) if we have it.

Make it respect Open Groups 1 second limit on usleep if not.



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@3978 d4fa192b-c00b-0410-8231-f00ffab90ce4

configure.ac

@@ -108,6 +108,7 @@ AC_CHECK_FUNCS([fmtcheck])
 AC_CHECK_FUNCS([getdtablesize])
 AC_CHECK_FUNCS([abort2])
 AC_CHECK_FUNCS([timegm])
+AC_CHECK_FUNCS([nanosleep])
 
 save_LIBS="${LIBS}"
 LIBS="${PTHREAD_LIBS}"

lib/libvarnish/time.c

@@ -152,10 +152,20 @@ TIM_parse(const char *p)
 void
 TIM_sleep(double t)
 {
-	if (t > 100.0)
-		(void)sleep((int)round(t));
-	else
-		(void)usleep((int)round(t * 1e6));
+	struct timespec ts;
+
+	ts.tv_sec = floor(t);
+	ts.tv_nsec = floor((t - ts.tv_sec) * 1e9);
+
+#ifdef HAVE_NANOSLEEP
+	(void)nanosleep(&ts, NULL);
+#else
+	if (ts.tv_sec > 0)
+		(void)sleep(ts.tv_sec);
+	ts.tv_nsec /= 1000;
+	if (ts.tv_nsec > 0)
+		(void)usleep(ts.tv_nsec);
+#endif
 }