Fix timestamps for etf queue

packet-exchange/src/client.c

@@ -34,6 +34,7 @@ typedef struct thread_param {
   int interval;
   int max_cycles;
   int priority;
+  int etf_offset;
 
   thread_stat_t stats;
 } thread_param_t;
@@ -78,11 +79,11 @@ struct timespec measures_start;
 struct timespec measures_end;
 
 static void help(char *argv[]) {
-  printf("Usage: %s -f IF  [-abethgv] [-d BUF_LEN] [-i USEC] [-l N] [-p PRIO] [-q PACKET_PRIO] [-r USEC]\n\n", argv[0]);
+  printf("Usage: %s -f IF  [-abthgv] [-e ETF_OFFSET] [-d BUF_LEN] [-i USEC] [-l N] [-p PRIO] [-q PACKET_PRIO] [-r USEC]\n\n", argv[0]);
   printf("       -a                    Run the real time thread on CPU1\n");
   printf("       -b                    Measure RTT\n");
   printf("       -d BUF_LEN            Set the length of tx buffer\n");
-  printf("       -e                    Set a txtime (to be used in an ETF qdisc)\n");
+  printf("       -e ETF_OFFSET         Set a txtime with an offset of ETF_OFFSET us (to be used in an ETF qdisc)\n");
   printf("       -f IF                 Set the network interface to be used\n");
   printf("       -g                    Print histograms to sdtout on exit\n");
   printf("       -h                    Show help\n");
@@ -119,13 +120,17 @@ static void *packet_sending_thread(void *p) {
   if (sched_setscheduler(0, SCHED_FIFO, &priority))
     error(EXIT_FAILURE, errno, "Couldn't set priority");
 
-  clock_gettime(CLOCK_MONOTONIC, &next);
-  next_txtime = next.tv_sec * NSEC_PER_SEC + next.tv_nsec;
-  // Wait around 1 second
-  next_txtime += (1 * NSEC_PER_SEC / param->interval) * param->interval;
-  // Send packet while thread is sleeping
-  next_txtime += (param->interval) / 2;
+  if(enable_etf) {
+    // Measure from CLOCK_TAI to generate timestamp
+    clock_gettime(CLOCK_TAI, &next);
+    next_txtime = next.tv_sec * NSEC_PER_SEC + next.tv_nsec;
+    next_txtime += param->etf_offset;
+  }
+  else {
+    next_txtime = 0;
+  }
 
+  clock_gettime(CLOCK_MONOTONIC, &next);
   clock_gettime(CLOCK_MONOTONIC, &measures_start);
   // Packet sending loop
   for (stats->nb_cycles = 0;; stats->nb_cycles++) {
@@ -136,7 +141,9 @@ static void *packet_sending_thread(void *p) {
     do_tsn_task(param, next_txtime);
 
     add_ns(&next, param->interval);
-    next_txtime += (param->interval);
+
+    if(enable_etf)
+      next_txtime += param->interval;
 
     clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &next, NULL);
   }
@@ -331,7 +338,7 @@ static void process_options(int argc, char *argv[]) {
   int network_if_specified = 0;
 
   for (;;) {
-    int c = getopt(argc, argv, "abd:ef:ghi:l:p:q:r:tv");
+    int c = getopt(argc, argv, "abd:e:f:ghi:l:p:q:r:tv");
 
     if (c == -1)
       break;
@@ -352,6 +359,7 @@ static void process_options(int argc, char *argv[]) {
       break;
     case 'e':
       enable_etf = 1;
+      param->etf_offset = atoi(optarg) * 1000;
       break;
     case 'f':
       network_if_specified = 1;