dig: Use high resolution clocks when microsecond accuracy is requested

The TIME_NOW macro calls isc_time_now which uses CLOCK_REALTIME_COARSE
for getting the current time. This is perfectly fine for millisecond,
however when the user request microsecond resolutiuon, they are going
to get very inaccurate results. This is especially true on a server
class machine where the clock ticks may be set to 100HZ.

This changes dig to use the new TIME_NOW_HIRES macro that uses the
CLOCK_MONOTONIC_RAW that is more expensive, but gets the *actual*
current time rather than the at the last kernel time tick.

diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
index 54bb63e5d1b196376caca26757414cca85740167..178c241708faaa8e46f42e4813c173c9b50e16ed 100644 (file)
--- a/bin/dig/dighost.c
+++ b/bin/dig/dighost.c
@@ -2866,7 +2866,11 @@ send_udp(dig_query_t *query) {
 
        isc_buffer_usedregion(&query->sendbuf, &r);
        debug("sending a request");
-       TIME_NOW(&query->time_sent);
+       if (query->lookup->use_usec) {
+               TIME_NOW_HIRES(&query->time_sent);
+       } else {
+               TIME_NOW(&query->time_sent);
+       }
 
        isc_nmhandle_attach(query->handle, &query->sendhandle);
 
@@ -3172,7 +3176,12 @@ launch_next_query(dig_query_t *query) {
        if (!query->first_soa_rcvd) {
                dig_query_t *sendquery = NULL;
                debug("sending a request in launch_next_query");
-               TIME_NOW(&query->time_sent);
+               if (query->lookup->use_usec) {
+                       TIME_NOW_HIRES(&query->time_sent);
+               } else {
+                       TIME_NOW(&query->time_sent);
+               }
+
                query_attach(query, &sendquery);
                isc_buffer_usedregion(&query->sendbuf, &r);
                if (keep != NULL) {
@@ -3584,7 +3593,11 @@ recv_done(isc_nmhandle_t *handle, isc_result_t eresult, isc_region_t *region,
                goto detach_query;
        }
 
-       TIME_NOW(&query->time_recv);
+       if (query->lookup->use_usec) {
+               TIME_NOW_HIRES(&query->time_recv);
+       } else {
+               TIME_NOW(&query->time_recv);
+       }
 
        if (eresult == ISC_R_TIMEDOUT && !l->tcp_mode && l->retries > 1) {
                dig_query_t *newq = NULL;

diff --git a/bin/dig/host.c b/bin/dig/host.c
index 02d9ce0f4856f858b9dff57d0f45203f98ea548e..b3ddc52f1a68deb3e381506284bf60dedea75519 100644 (file)
--- a/bin/dig/host.c
+++ b/bin/dig/host.c
@@ -151,7 +151,11 @@ received(unsigned int bytes, isc_sockaddr_t *from, dig_query_t *query) {
        if (!short_form) {
                char fromtext[ISC_SOCKADDR_FORMATSIZE];
                isc_sockaddr_format(from, fromtext, sizeof(fromtext));
-               TIME_NOW(&now);
+               if (query->lookup->use_usec) {
+                       TIME_NOW_HIRES(&now);
+               } else {
+                       TIME_NOW(&now);
+               }
                diff = (int)isc_time_microdiff(&now, &query->time_sent);
                printf("Received %u bytes from %s in %d ms\n", bytes, fromtext,
                       diff / 1000);