diff --git a/src/examples/roundtrip/ping.c b/src/examples/roundtrip/ping.c
index e94c277..7e39d70 100644
--- a/src/examples/roundtrip/ping.c
+++ b/src/examples/roundtrip/ping.c
@@ -12,7 +12,7 @@
 
 /* Forward declaration */
 
-static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_entity_t *readCond);
+static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_entity_t *readCond, dds_listener_t *listener);
 static void finalize_dds(dds_entity_t participant, dds_entity_t reader, dds_entity_t readCond);
 
 typedef struct ExampleTimeStats
@@ -101,6 +101,12 @@ static double exampleGetMedianFromTimeStats (ExampleTimeStats *stats)
   return median;
 }
 
+static dds_time_t exampleGet99PercentileFromTimeStats (ExampleTimeStats *stats)
+{
+  qsort (stats->values, stats->valuesSize, sizeof (dds_time_t), exampleCompareul);
+  return stats->values[stats->valuesSize - stats->valuesSize / 100];
+}
+
 static dds_entity_t waitSet;
 
 #ifdef _WIN32
@@ -117,44 +123,124 @@ static void CtrlHandler (int fdwCtrlType)
 }
 #endif
 
+static dds_entity_t writer;
+static dds_entity_t reader;
+static dds_entity_t participant;
+static dds_entity_t readCond;
+
+static ExampleTimeStats roundTrip;
+static ExampleTimeStats writeAccess;
+static ExampleTimeStats readAccess;
+static ExampleTimeStats roundTripOverall;
+static ExampleTimeStats writeAccessOverall;
+static ExampleTimeStats readAccessOverall;
+
+static RoundTripModule_DataType pub_data;
+static RoundTripModule_DataType sub_data[MAX_SAMPLES];
+static void *samples[MAX_SAMPLES];
+static dds_sample_info_t info[MAX_SAMPLES];
+
+static dds_time_t startTime;
+static dds_time_t preWriteTime;
+static dds_time_t postWriteTime;
+static dds_time_t preTakeTime;
+static dds_time_t postTakeTime;
+static dds_time_t elapsed = 0;
+
+static bool warmUp = true;
+
+static void data_available(dds_entity_t reader, void *arg)
+{
+  dds_time_t difference = 0;
+  int status;
+  (void)arg;
+  /* Take sample and check that it is valid */
+  preTakeTime = dds_time ();
+  status = dds_take (reader, samples, info, MAX_SAMPLES, MAX_SAMPLES);
+  DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  postTakeTime = dds_time ();
+
+  /* Update stats */
+  difference = (postWriteTime - preWriteTime)/DDS_NSECS_IN_USEC;
+  writeAccess = *exampleAddTimingToTimeStats (&writeAccess, difference);
+  writeAccessOverall = *exampleAddTimingToTimeStats (&writeAccessOverall, difference);
+
+  difference = (postTakeTime - preTakeTime)/DDS_NSECS_IN_USEC;
+  readAccess = *exampleAddTimingToTimeStats (&readAccess, difference);
+  readAccessOverall = *exampleAddTimingToTimeStats (&readAccessOverall, difference);
+
+  difference = (postTakeTime - info[0].source_timestamp)/DDS_NSECS_IN_USEC;
+  roundTrip = *exampleAddTimingToTimeStats (&roundTrip, difference);
+  roundTripOverall = *exampleAddTimingToTimeStats (&roundTripOverall, difference);
+
+  if (!warmUp) {
+    /* Print stats each second */
+    difference = (postTakeTime - startTime)/DDS_NSECS_IN_USEC;
+    if (difference > US_IN_ONE_SEC)
+    {
+      printf("%9" PRIi64 " %9lu %8.0f %8" PRIi64 " %8" PRIi64 " %8" PRIi64 " %10lu %8.0f %8" PRIi64 " %10lu %8.0f %8" PRIi64 "\n",
+             elapsed + 1,
+             roundTrip.count,
+             exampleGetMedianFromTimeStats (&roundTrip),
+             roundTrip.min,
+             exampleGet99PercentileFromTimeStats (&roundTrip),
+             roundTrip.max,
+             writeAccess.count,
+             exampleGetMedianFromTimeStats (&writeAccess),
+             writeAccess.min,
+             readAccess.count,
+             exampleGetMedianFromTimeStats (&readAccess),
+             readAccess.min);
+
+      exampleResetTimeStats (&roundTrip);
+      exampleResetTimeStats (&writeAccess);
+      exampleResetTimeStats (&readAccess);
+      startTime = dds_time ();
+      elapsed++;
+    }
+  }
+
+  preWriteTime = dds_time();
+  status = dds_write_ts (writer, &pub_data, preWriteTime);
+  DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  postWriteTime = dds_time();
+}
+
+static void usage(void)
+{
+  printf ("Usage (parameters must be supplied in order):\n"
+          "./ping [-l] [payloadSize (bytes, 0 - 100M)] [numSamples (0 = infinite)] [timeOut (seconds, 0 = infinite)]\n"
+          "./ping quit - ping sends a quit signal to pong.\n"
+          "Defaults:\n"
+          "./ping 0 0 0\n");
+  exit(EXIT_FAILURE);
+}
+
 int main (int argc, char *argv[])
 {
-  dds_entity_t writer;
-  dds_entity_t reader;
-  dds_entity_t participant;
-  dds_entity_t readCond;
-
-  ExampleTimeStats roundTrip;
-  ExampleTimeStats writeAccess;
-  ExampleTimeStats readAccess;
-  ExampleTimeStats roundTripOverall;
-  ExampleTimeStats writeAccessOverall;
-  ExampleTimeStats readAccessOverall;
-
   unsigned long payloadSize = 0;
   unsigned long long numSamples = 0;
   bool invalidargs = false;
   dds_time_t timeOut = 0;
-  dds_time_t startTime;
   dds_time_t time;
-  dds_time_t preWriteTime;
-  dds_time_t postWriteTime;
-  dds_time_t preTakeTime;
-  dds_time_t postTakeTime;
   dds_time_t difference = 0;
-  dds_time_t elapsed = 0;
-
-  RoundTripModule_DataType pub_data;
-  RoundTripModule_DataType sub_data[MAX_SAMPLES];
-  void *samples[MAX_SAMPLES];
-  dds_sample_info_t info[MAX_SAMPLES];
 
   dds_attach_t wsresults[1];
   size_t wsresultsize = 1U;
   dds_time_t waitTimeout = DDS_SECS (1);
   unsigned long i;
   int status;
-  bool warmUp = true;
+
+  dds_listener_t *listener = NULL;
+  bool use_listener = false;
+  int argidx = 1;
+
+  /* poor man's getopt works even on Windows */
+  if (argc > argidx && strcmp(argv[argidx], "-l") == 0)
+  {
+    argidx++;
+    use_listener = true;
+  }
 
   /* Register handler for Ctrl-C */
 #ifdef _WIN32
@@ -182,11 +268,17 @@ int main (int argc, char *argv[])
     samples[i] = &sub_data[i];
   }
 
-  participant = prepare_dds(&writer, &reader, &readCond);
+  participant = dds_create_participant (DDS_DOMAIN_DEFAULT, NULL, NULL);
+  DDS_ERR_CHECK (participant, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+
+  listener = dds_listener_create(NULL);
+  dds_lset_data_available(listener, data_available);
+
+  prepare_dds(&writer, &reader, &readCond, listener);
 
   setvbuf(stdout, NULL, _IONBF, 0);
 
-  if (argc == 2 && strcmp (argv[1], "quit") == 0)
+  if (argc - argidx == 1 && strcmp (argv[argidx], "quit") == 0)
   {
     printf ("Sending termination request.\n");
     /* pong uses a waitset which is triggered by instance disposal, and
@@ -202,36 +294,29 @@ int main (int argc, char *argv[])
     goto done;
   }
 
-  if (argc == 1)
+  if (argc - argidx == 0)
   {
     invalidargs = true;
   }
-  if (argc >= 2)
+  if (argc - argidx >= 1)
   {
-    payloadSize = atol (argv[1]);
+    payloadSize = atol (argv[argidx]);
 
-    if (payloadSize > 65536)
+    if (payloadSize > 100 * 1048576)
     {
       invalidargs = true;
     }
   }
-  if (argc >= 3)
+  if (argc - argidx >= 2)
   {
-    numSamples = atol (argv[2]);
+    numSamples = atol (argv[argidx+1]);
   }
-  if (argc >= 4)
+  if (argc - argidx >= 3)
   {
-    timeOut = atol (argv[3]);
-  }
-  if (invalidargs || (argc == 2 && (strcmp (argv[1], "-h") == 0 || strcmp (argv[1], "--help") == 0)))
-  {
-    printf ("Usage (parameters must be supplied in order):\n"
-            "./ping [payloadSize (bytes, 0 - 65536)] [numSamples (0 = infinite)] [timeOut (seconds, 0 = infinite)]\n"
-            "./ping quit - ping sends a quit signal to pong.\n"
-            "Defaults:\n"
-            "./ping 0 0 0\n");
-    return EXIT_FAILURE;
+    timeOut = atol (argv[argidx+2]);
   }
+  if (invalidargs || (argc - argidx == 1 && (strcmp (argv[argidx], "-h") == 0 || strcmp (argv[argidx], "--help") == 0)))
+    usage();
   printf ("# payloadSize: %lu | numSamples: %llu | timeOut: %" PRIi64 "\n\n", payloadSize, numSamples, timeOut);
 
   pub_data.payload._length = payloadSize;
@@ -245,13 +330,12 @@ int main (int argc, char *argv[])
 
   startTime = dds_time ();
   printf ("# Waiting for startup jitter to stabilise\n");
+  /* Write a sample that pong can send back */
   while (!dds_triggered (waitSet) && difference < DDS_SECS(5))
   {
-    status = dds_write (writer, &pub_data);
-    DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
     status = dds_waitset_wait (waitSet, wsresults, wsresultsize, waitTimeout);
     DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-    if (status > 0) /* data */
+    if (status > 0 && listener == NULL) /* data */
     {
       status = dds_take (reader, samples, info, MAX_SAMPLES, MAX_SAMPLES);
       DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
@@ -266,93 +350,26 @@ int main (int argc, char *argv[])
     printf("# Warm up complete.\n\n");
 
     printf("# Round trip measurements (in us)\n");
-    printf("#             Round trip time [us]         Write-access time [us]       Read-access time [us]\n");
-    printf("# Seconds     Count   median      min      Count   median      min      Count   median      min\n");
+    printf("#             Round trip time [us]                           Write-access time [us]       Read-access time [us]\n");
+    printf("# Seconds     Count   median      min      99%%      max      Count   median      min      Count   median      min\n");
 
   }
 
+  exampleResetTimeStats (&roundTrip);
+  exampleResetTimeStats (&writeAccess);
+  exampleResetTimeStats (&readAccess);
   startTime = dds_time ();
+  /* Write a sample that pong can send back */
+  preWriteTime = dds_time ();
+  status = dds_write_ts (writer, &pub_data, preWriteTime);
+  DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  postWriteTime = dds_time ();
   for (i = 0; !dds_triggered (waitSet) && (!numSamples || i < numSamples); i++)
   {
-    /* Write a sample that pong can send back */
-    preWriteTime = dds_time ();
-    status = dds_write (writer, &pub_data);
-    DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-    postWriteTime = dds_time ();
-
-    /* Wait for response from pong */
     status = dds_waitset_wait (waitSet, wsresults, wsresultsize, waitTimeout);
     DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-    if (status != 0)
-    {
-      /* Take sample and check that it is valid */
-      preTakeTime = dds_time ();
-      status = dds_take (reader, samples, info, MAX_SAMPLES, MAX_SAMPLES);
-      DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-      postTakeTime = dds_time ();
-
-      if (!dds_triggered (waitSet))
-      {
-        if (status != 1)
-        {
-          fprintf (stdout, "%s%d%s", "ERROR: Ping received ", status,
-                  " samples but was expecting 1. Are multiple pong applications running?\n");
-
-          goto done;
-        }
-        else if (!info[0].valid_data)
-        {
-          printf ("ERROR: Ping received an invalid sample. Has pong terminated already?\n");
-          goto done;
-        }
-      }
-
-      /* Update stats */
-      difference = (postWriteTime - preWriteTime)/DDS_NSECS_IN_USEC;
-      writeAccess = *exampleAddTimingToTimeStats (&writeAccess, difference);
-      writeAccessOverall = *exampleAddTimingToTimeStats (&writeAccessOverall, difference);
-
-      difference = (postTakeTime - preTakeTime)/DDS_NSECS_IN_USEC;
-      readAccess = *exampleAddTimingToTimeStats (&readAccess, difference);
-      readAccessOverall = *exampleAddTimingToTimeStats (&readAccessOverall, difference);
-
-      difference = (postTakeTime - preWriteTime)/DDS_NSECS_IN_USEC;
-      roundTrip = *exampleAddTimingToTimeStats (&roundTrip, difference);
-      roundTripOverall = *exampleAddTimingToTimeStats (&roundTripOverall, difference);
-
-      /* Print stats each second */
-      difference = (postTakeTime - startTime)/DDS_NSECS_IN_USEC;
-      if (difference > US_IN_ONE_SEC || (i && i == numSamples))
-      {
-        printf
-        (
-          "%9" PRIi64 " %9lu %8.0f %8" PRIi64 " %10lu %8.0f %8" PRIi64 " %10lu %8.0f %8" PRIi64 "\n",
-          elapsed + 1,
-          roundTrip.count,
-          exampleGetMedianFromTimeStats (&roundTrip),
-          roundTrip.min,
-          writeAccess.count,
-          exampleGetMedianFromTimeStats (&writeAccess),
-          writeAccess.min,
-          readAccess.count,
-          exampleGetMedianFromTimeStats (&readAccess),
-          readAccess.min
-        );
-
-        exampleResetTimeStats (&roundTrip);
-        exampleResetTimeStats (&writeAccess);
-        exampleResetTimeStats (&readAccess);
-        startTime = dds_time ();
-        elapsed++;
-      }
-    }
-    else
-    {
-      elapsed += waitTimeout / DDS_NSECS_IN_SEC;
-    }
-    if (timeOut && elapsed == timeOut)
-    {
-      dds_waitset_set_trigger (waitSet, true);
+    if (status != 0 && listener == NULL) {
+      data_available(reader, NULL);
     }
   }
 
@@ -401,7 +418,7 @@ done:
   return EXIT_SUCCESS;
 }
 
-static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_entity_t *readCond)
+static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_entity_t *readCond, dds_listener_t *listener)
 {
   dds_return_t status;
   dds_entity_t topic;
@@ -415,9 +432,6 @@ static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_
   dds_qos_t *drQos;
   dds_qos_t *subQos;
 
-  dds_entity_t participant = dds_create_participant (DDS_DOMAIN_DEFAULT, NULL, NULL);
-  DDS_ERR_CHECK (participant, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-
   /* A DDS_Topic is created for our sample type on the domain participant. */
   topic = dds_create_topic (participant, &RoundTripModule_DataType_desc, "RoundTrip", NULL, NULL);
   DDS_ERR_CHECK (topic, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
@@ -449,15 +463,18 @@ static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_
   /* A DDS_DataReader is created on the Subscriber & Topic with a modified QoS. */
   drQos = dds_qos_create ();
   dds_qset_reliability (drQos, DDS_RELIABILITY_RELIABLE, DDS_SECS(10));
-  *reader = dds_create_reader (subscriber, topic, drQos, NULL);
+  *reader = dds_create_reader (subscriber, topic, drQos, listener);
   DDS_ERR_CHECK (*reader, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
   dds_qos_delete (drQos);
 
   waitSet = dds_create_waitset (participant);
-  *readCond = dds_create_readcondition (*reader, DDS_ANY_STATE);
-
-  status = dds_waitset_attach (waitSet, *readCond, *reader);
-  DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  if (listener == NULL) {
+    *readCond = dds_create_readcondition (*reader, DDS_ANY_STATE);
+    status = dds_waitset_attach (waitSet, *readCond, *reader);
+    DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  } else {
+    *readCond = 0;
+  }
   status = dds_waitset_attach (waitSet, waitSet, waitSet);
   DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
 
@@ -471,12 +488,10 @@ static void finalize_dds(dds_entity_t participant, dds_entity_t reader, dds_enti
   /* Disable callbacks */
   dds_set_enabled_status (reader, 0);
 
-  status = dds_waitset_detach (waitSet, readCond);
-  DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  (void) dds_waitset_detach (waitSet, readCond);
   status = dds_waitset_detach (waitSet, waitSet);
   DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-  status = dds_delete (readCond);
-  DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  (void) dds_delete (readCond);
   status = dds_delete (waitSet);
   DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
   status = dds_delete (participant);
diff --git a/src/examples/roundtrip/pong.c b/src/examples/roundtrip/pong.c
index fa39cdd..371b072 100644
--- a/src/examples/roundtrip/pong.c
+++ b/src/examples/roundtrip/pong.c
@@ -10,7 +10,7 @@ static dds_entity_t waitSet;
 #define MAX_SAMPLES 10
 
 /* Forward declarations */
-static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_entity_t *readCond);
+static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_entity_t *readCond, dds_listener_t *listener);
 static void finalize_dds(dds_entity_t participant, dds_entity_t readCond, RoundTripModule_DataType data[MAX_SAMPLES]);
 
 #ifdef _WIN32
@@ -27,21 +27,58 @@ static void CtrlHandler (int fdwCtrlType)
 }
 #endif
 
+static RoundTripModule_DataType data[MAX_SAMPLES];
+static void * samples[MAX_SAMPLES];
+static dds_sample_info_t info[MAX_SAMPLES];
+
+static dds_entity_t participant;
+static dds_entity_t reader;
+static dds_entity_t writer;
+static dds_entity_t readCond;
+
+static void data_available(dds_entity_t reader, void *arg)
+{
+  int status, samplecount;
+  (void)arg;
+  samplecount = dds_take (reader, samples, info, MAX_SAMPLES, MAX_SAMPLES);
+  DDS_ERR_CHECK (samplecount, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  for (int j = 0; !dds_triggered (waitSet) && j < samplecount; j++)
+  {
+    /* If writer has been disposed terminate pong */
+
+    if (info[j].instance_state == DDS_IST_NOT_ALIVE_DISPOSED)
+    {
+      printf ("Received termination request. Terminating.\n");
+      dds_waitset_set_trigger (waitSet, true);
+      break;
+    }
+    else if (info[j].valid_data)
+    {
+      /* If sample is valid, send it back to ping */
+      RoundTripModule_DataType * valid_sample = &data[j];
+      status = dds_write_ts (writer, valid_sample, info[j].source_timestamp);
+      DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+    }
+  }
+}
+
 int main (int argc, char *argv[])
 {
   dds_duration_t waitTimeout = DDS_INFINITY;
   unsigned int i;
-  int status, samplecount, j;
+  int status;
   dds_attach_t wsresults[1];
   size_t wsresultsize = 1U;
-  dds_entity_t participant;
-  dds_entity_t reader;
-  dds_entity_t writer;
-  dds_entity_t readCond;
 
-  RoundTripModule_DataType data[MAX_SAMPLES];
-  void * samples[MAX_SAMPLES];
-  dds_sample_info_t info[MAX_SAMPLES];
+  dds_listener_t *listener = NULL;
+  bool use_listener = false;
+  int argidx = 1;
+
+  if (argc > argidx && strcmp(argv[argidx], "-l") == 0)
+  {
+    argidx++;
+    use_listener = true;
+  }
 
   /* Register handler for Ctrl-C */
 
@@ -55,8 +92,6 @@ int main (int argc, char *argv[])
   sigaction (SIGINT, &sat, &oldAction);
 #endif
 
-  participant = prepare_dds(&writer, &reader, &readCond);
-
   /* Initialize sample data */
   memset (data, 0, sizeof (data));
   for (i = 0; i < MAX_SAMPLES; i++)
@@ -64,6 +99,17 @@ int main (int argc, char *argv[])
     samples[i] = &data[i];
   }
 
+  participant = dds_create_participant (DDS_DOMAIN_DEFAULT, NULL, NULL);
+  DDS_ERR_CHECK (participant, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+
+  if (use_listener)
+  {
+    listener = dds_listener_create(NULL);
+    dds_lset_data_available(listener, data_available);
+  }
+
+  (void)prepare_dds(&writer, &reader, &readCond, listener);
+
   while (!dds_triggered (waitSet))
   {
     /* Wait for a sample from ping */
@@ -72,25 +118,8 @@ int main (int argc, char *argv[])
     DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
 
     /* Take samples */
-    samplecount = dds_take (reader, samples, info, MAX_SAMPLES, MAX_SAMPLES);
-    DDS_ERR_CHECK (samplecount, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-    for (j = 0; !dds_triggered (waitSet) && j < samplecount; j++)
-    {
-      /* If writer has been disposed terminate pong */
-
-      if (info[j].instance_state == DDS_IST_NOT_ALIVE_DISPOSED)
-      {
-        printf ("Received termination request. Terminating.\n");
-        dds_waitset_set_trigger (waitSet, true);
-        break;
-      }
-      else if (info[j].valid_data)
-      {
-        /* If sample is valid, send it back to ping */
-        RoundTripModule_DataType * valid_sample = &data[j];
-        status = dds_write (writer, valid_sample);
-        DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-      }
+    if (listener == NULL) {
+      data_available (reader, 0);
     }
   }
 
@@ -108,12 +137,11 @@ int main (int argc, char *argv[])
 
 static void finalize_dds(dds_entity_t participant, dds_entity_t readCond, RoundTripModule_DataType data[MAX_SAMPLES])
 {
-  dds_return_t status = dds_waitset_detach (waitSet, readCond);
-  DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  dds_return_t status;
+  (void)dds_waitset_detach (waitSet, readCond);
   status = dds_waitset_detach (waitSet, waitSet);
   DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-  status = dds_delete (readCond);
-  DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  (void)dds_delete (readCond);
   status = dds_delete (waitSet);
   DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
   status = dds_delete (participant);
@@ -125,7 +153,7 @@ static void finalize_dds(dds_entity_t participant, dds_entity_t readCond, RoundT
   }
 }
 
-static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_entity_t *readCond)
+static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_entity_t *readCond, dds_listener_t *listener)
 {
   const char *pubPartitions[] = { "pong" };
   const char *subPartitions[] = { "ping" };
@@ -135,9 +163,6 @@ static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_
   dds_entity_t topic;
   dds_return_t status;
 
-  dds_entity_t participant = dds_create_participant (DDS_DOMAIN_DEFAULT, NULL, NULL);
-  DDS_ERR_CHECK (participant, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
-
   /* A DDS Topic is created for our sample type on the domain participant. */
 
   topic = dds_create_topic (participant, &RoundTripModule_DataType_desc, "RoundTrip", NULL, NULL);
@@ -174,14 +199,18 @@ static dds_entity_t prepare_dds(dds_entity_t *writer, dds_entity_t *reader, dds_
 
   qos = dds_qos_create ();
   dds_qset_reliability (qos, DDS_RELIABILITY_RELIABLE, DDS_SECS(10));
-  *reader = dds_create_reader (subscriber, topic, qos, NULL);
+  *reader = dds_create_reader (subscriber, topic, qos, listener);
   DDS_ERR_CHECK (*reader, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
   dds_qos_delete (qos);
 
   waitSet = dds_create_waitset (participant);
-  *readCond = dds_create_readcondition (*reader, DDS_ANY_STATE);
-  status = dds_waitset_attach (waitSet, *readCond, *reader);
-  DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  if (listener == NULL) {
+    *readCond = dds_create_readcondition (*reader, DDS_ANY_STATE);
+    status = dds_waitset_attach (waitSet, *readCond, *reader);
+    DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);
+  } else {
+    *readCond = 0;
+  }
   status = dds_waitset_attach (waitSet, waitSet, waitSet);
   DDS_ERR_CHECK (status, DDS_CHECK_REPORT | DDS_CHECK_EXIT);