Changeset 4764 for developers/werner/owping/rx.c

Timestamp:

11/07/08 04:37:29 (5 years ago)

Author:

werner

Message:

• added README with a list of known issues
• receiver prints ping-like latency statistics at the end
• sender supports -c count option, like ping
• sender properly shuts down the receiver if failing or stopped with SIGINT

File:

• developers/werner/owping/rx.c (modified) (6 diffs)

developers/werner/owping/rx.c

@@ -15 +15 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
+#include <math.h>
 #include <sys/time.h>
 #include <sys/socket.h>
@@ -23 +25 @@
 
 
-static void delta(struct timeval t0, struct timeval t1)
+struct stats {
+    long min, max;
+    double sum, sq;
+    int n;
+};
+
+
+static void stats_init(struct stats *stats)
 {
+    memset(stats, 0, sizeof(*stats));
+}
+
+
+static void stats_print(const char *label, const struct stats *stats)
+{
+    double avg = stats->sum/stats->n;
+
+    printf("%s min/avg/max/sdev = %.3f/%.3f/%.3f/%.3f ms (%d packets)\n",
+      label,
+      stats->min/1000.0, avg/1000.0, stats->max/1000.0,
+      sqrt(stats->sq/stats->n-avg*avg)/1000.0,
+      stats->n);
+}
+
+
+static void delta(struct timeval t0, struct timeval t1, struct stats *stats)
+{
+    char sign = ' ';
     long us;
 
     us = t1.tv_usec-t0.tv_usec;
     us += (t1.tv_sec-t0.tv_sec)*1000000;
-    printf(" %ld.%03ldms", us/1000, us % 1000);
+
+    if (!stats->n) {
+        stats->min = stats->max = us;
+    } else {
+        if (stats->min > us)
+            stats->min = us;
+        if (stats->max < us)
+            stats->max = us;
+    }
+    stats->n++;
+    stats->sum += us;
+    stats->sq += (double) us*us;
+
+    if (us < 0) {
+        us = -us;
+        sign = '-';
+    }
+    printf(" %c%ld.%03ldms", sign, us/1000, us % 1000);
 }
 
@@ -35 +80 @@
 void rx(int port)
 {
+    struct stats stats_itf, stats_user;
     struct sockaddr_in addr;
     int s;
@@ -52 +98 @@
     }
     
-    // setsockopt timestamp
+    stats_init(&stats_itf);
+    stats_init(&stats_user);
 
     while (1) {
@@ -68 +115 @@
         }
         if (got == 1)
-            return;
+            break;
         if (got != sizeof(buf)) {
             fprintf(stderr, "bad read: expected %u, got %u\n",
@@ -86 +133 @@
         t_src.tv_sec = ntohl(buf.tv_sec);
         t_src.tv_usec = ntohl(buf.tv_usec);
-        delta(t_src, t_itf);
-        delta(t_src, t_user);
+        delta(t_src, t_itf, &stats_itf);
+        delta(t_src, t_user, &stats_user);
         putchar('\n');
     }
+    stats_print("itf:", &stats_itf);
+    stats_print("app:", &stats_user);
+
 }