Try to improve rrl timing

Add a +burst option to mdig so that we have a second to setup the
mdig calls then they run at the start of the next second.

RRL uses 'queries in a second' as a approximation to
'queries per second'. Getting the bursts of traffic to all happen in
the same second should prevent false negatives in the system test.

We now have a second to setup the traffic in.  Then the traffic should
be sent at the start of the next second.  If that still fails we
should move to +burst=<now+2> (further extend mdig) instead of the
implicit <now+1> as the trigger second.

bin/tests/system/rrl/tests.sh

@@ -80,7 +80,7 @@ burst () {
         eval BURST_DOM="$BURST_DOM_BASE"
         DOMS="$DOMS $BURST_DOM"
     done
-    ARGS="+nocookie +continue +time=1 +tries=1 -p ${PORT} $* @$ns2 $DOMS"
+    ARGS="+burst +nocookie +continue +time=1 +tries=1 -p ${PORT} $* @$ns2 $DOMS"
     $MDIG $ARGS 2>&1 |                                                  \
         tr -d '\r' |                                                    \
         tee -a full-$FILENAME |                                         \
@@ -92,7 +92,7 @@ burst () {
 		-e 's/;; .* status: NOERROR.*/NOERROR/p'		\
 		-e 's/;; .* status: SERVFAIL.*/SERVFAIL/p'		\
 		-e 's/response failed with timed out.*/drop/p'		\
-		-e 's/;; communications error to.*/drop/p' >> $FILENAME
+		-e 's/;; communications error to.*/drop/p' >> $FILENAME &
     QNUM=`expr $QNUM + $BURST_LIMIT`
 }
 
@@ -104,6 +104,8 @@ range () {
 #   $1=domain  $2=IP address  $3=# of IP addresses  $4=TC  $5=drop
 #	$6=NXDOMAIN  $7=SERVFAIL or other errors
 ck_result() {
+    # wait to the background mdig calls to complete.
+    wait
     BAD=no
     ADDRS=`egrep "^$2$" mdig.out-$1				2>/dev/null | wc -l`
     # count simple truncated and truncated NXDOMAIN as TC

bin/tools/mdig.c

@@ -83,10 +83,15 @@
 #define UDPTIMEOUT 5
 #define MAXTRIES   0xffffffff
 
+#define NS_PER_US  1000	   /*%< Nanoseconds per microsecond. */
+#define US_PER_SEC 1000000 /*%< Microseconds per second. */
+#define US_PER_MS  1000	   /*%< Microseconds per millisecond. */
+
 static isc_mem_t *mctx;
 static dns_requestmgr_t *requestmgr;
 static const char *batchname;
 static FILE *batchfp;
+static bool burst = false;
 static bool have_ipv4 = false;
 static bool have_ipv6 = false;
 static bool have_src = false;
@@ -1222,7 +1227,9 @@ plus_option(char *option, struct query *query, bool global) {
 			GLOBAL();
 			besteffort = state;
 			break;
-		case 'u': /* bufsize */
+		case 'u':
+			switch (cmd[2]) {
+			case 'f': /* bufsize */
 				FULLCHECK("bufsize");
 				if (value == NULL) {
 					goto need_value;
@@ -1235,6 +1242,15 @@ plus_option(char *option, struct query *query, bool global) {
 				CHECK("parse_uint(buffer size)", result);
 				query->udpsize = num;
 				break;
+			case 'r': /* burst */
+				FULLCHECK("burst");
+				GLOBAL();
+				burst = state;
+				break;
+			default:
+				goto invalid_option;
+			}
+			break;
 		default:
 			goto invalid_option;
 		}
@@ -2044,6 +2060,21 @@ parse_args(bool is_batchfile, int argc, char **argv) {
 	}
 }
 
+#ifdef WIN32
+static void
+usleep(unsigned int usec) {
+	HANDLE timer;
+	LARGE_INTEGER ft;
+
+	ft.QuadPart = -(10 * (__int64)usec);
+
+	timer = CreateWaitableTimer(NULL, TRUE, NULL);
+	SetWaitableTimer(timer, &ft, 0, NULL, NULL, 0);
+	WaitForSingleObject(timer, INFINITE);
+	CloseHandle(timer);
+}
+#endif
+
 /*% Main processing routine for mdig */
 int
 main(int argc, char *argv[]) {
@@ -2152,6 +2183,32 @@ main(int argc, char *argv[]) {
 	query = ISC_LIST_HEAD(queries);
 	RUNCHECK(isc_app_onrun(mctx, task, sendqueries, query));
 
+	/*
+	 * Stall to the start of a new second.
+	 */
+	if (burst) {
+		isc_time_t start, now;
+		RUNCHECK(isc_time_now(&start));
+		/*
+		 * Sleep to 1ms of the end of the second then run a busy loop
+		 * until the second changes.
+		 */
+		do {
+			RUNCHECK(isc_time_now(&now));
+			if (isc_time_seconds(&start) == isc_time_seconds(&now))
+			{
+				int us = US_PER_SEC -
+					 (isc_time_nanoseconds(&now) /
+					  NS_PER_US);
+				if (us > US_PER_MS) {
+					usleep(us - US_PER_MS);
+				}
+			} else {
+				break;
+			}
+		} while (1);
+	}
+
 	(void)isc_app_run();
 
 	query = ISC_LIST_HEAD(queries);

bin/tools/mdig.rst

@@ -130,6 +130,9 @@ The global query options are:
    This option attempts to display [or does not display] the contents of messages which are malformed. The
    default is to not display malformed answers.
 
+``+burst``
+   This option delays queries until the start of the next second.
+
 ``+[no]cl``
    This option displays [or does not display] the CLASS when printing the record.
 

doc/man/mdig.1in

@@ -132,6 +132,9 @@ default is to display it.
 This option attempts to display [or does not display] the contents of messages which are malformed. The
 default is to not display malformed answers.
 .TP
+.B \fB+burst\fP
+This option delays queries until the start of the next second.
+.TP
 .B \fB+[no]cl\fP
 This option displays [or does not display] the CLASS when printing the record.
 .TP