Add histogram printing for RTT

packet-exchange/src/client.c

@@ -250,6 +250,9 @@ static void do_tsn_task(struct thread_param *param, uint64_t next_txtime) {
     clock_gettime(CLOCK_MONOTONIC, &t2);
 
     param->stats.rtt = calcdiff_ns(t2, t1);
+
+    if(enable_histograms)
+      histograms[0][param->stats.rtt]++;
   }
 }
 
@@ -258,6 +261,7 @@ static void print_histograms() {
 
   uint64_t duration;
   int duration_hour, duration_minutes, interval;
+  int max_hist_val, nb_hists;
 
   clock_gettime(CLOCK_MONOTONIC, &measures_end);
 
@@ -267,6 +271,7 @@ static void print_histograms() {
 
   interval = param->interval / 1000;
 
+  if(tsn_task == SEND_PACKET_TASK) {
     printf("{\"measure_sets\": [{"
                "\"measure_type\": \"packet_send_timestamps\","
                "\"props_names\": [\"user_space\", \"kernel_space\"],"
@@ -276,18 +281,31 @@ static void print_histograms() {
                   "\"i\": \"%dus\", \"duration\": \"%dh%d\""
                 "},"
                "\"props\": [", interval, duration_hour, duration_minutes);
+  } else if(tsn_task == RTT_TASK) {
+    printf("{\"measure_sets\": [{"
+               "\"measure_type\": \"packet_rtt\","
+               "\"props_names\": [\"rtt\"],"
+               "\"units\": [\"us\"],"
+               "\"props_type\": \"histogram\","
+               "\"metadata\": {"
+                  "\"i\": \"%dus\", \"duration\": \"%dh%d\""
+                "},"
+               "\"props\": [", interval, duration_hour, duration_minutes);
+  }
+
+  nb_hists = tsn_task == SEND_PACKET_TASK ? 2 : 1;
 
-  int max_hist_val = 0;
-  for (int i = 0; i < 2; i++)
+  max_hist_val = 0;
+  for (int i = 0; i < nb_hists; i++)
     for (int j = 0; j < MAX_HIST_VAL; j++)
       if (histograms[i][j])
         max_hist_val = j > max_hist_val ? j : max_hist_val;
 
-  for (int i = 0; i < 2; i++) {
+  for (int i = 0; i < nb_hists; i++) {
     printf("[");
     for (int j = 0; j < max_hist_val; j++)
       printf("%" PRIi64 "%s", histograms[i][j], (j + 1 < max_hist_val ? ", " : ""));
-    printf("%s", (i + 1 < 2 ? "], " : "]"));
+    printf("%s", (i + 1 < nb_hists ? "], " : "]"));
   }
 
   printf(   "]}]}\n");