Fix periodic mode in latester
authorMichal Sojka <sojkam1@fel.cvut.cz>
Tue, 14 Jan 2014 15:04:58 +0000 (16:04 +0100)
committerMichal Sojka <sojkam1@fel.cvut.cz>
Tue, 14 Jan 2014 15:09:22 +0000 (16:09 +0100)
In previous versions periodic mode was broken and messages were note
sent periodically. The reason was that time to next period was advanced
with every return of ppoll(), not only with ppoll() timeouts.

latester/latester.c

index a4f825c..8b1fb86 100644 (file)
@@ -427,26 +427,34 @@ static inline void send_and_check(int s)
        }
 }
 
-static inline void get_next_timeout(struct timespec *timeout)
+static inline void get_next_timeout(struct timespec *timeout, bool advance)
 {
        struct timespec now;
        static struct timespec last = {-1, 0 };
 
        clock_gettime(CLOCK_MONOTONIC, &now);
 
-       if (last.tv_sec == -1)
+       if (last.tv_sec == -1) {
                last = now;
+               last.tv_nsec = last.tv_nsec/1000000*1000000;
+       }
        if (opt.period_us != 0) {
-               last.tv_sec += opt.period_us/1000000;
-               last.tv_nsec += (opt.period_us%1000000)*1000;
-               while (last.tv_nsec >= 1000000000) {
-                       last.tv_nsec -= 1000000000;
-                       last.tv_sec++;
+               if (advance) {
+                       last.tv_sec += opt.period_us/1000000;
+                       last.tv_nsec += (opt.period_us%1000000)*1000;
+                       while (last.tv_nsec >= 1000000000) {
+                               last.tv_nsec -= 1000000000;
+                               last.tv_sec++;
+                       }
                }
                if (timespec_subtract(timeout, &last, &now) /* is negative */) {
                        stats.overrun++;
                        memset(timeout, 0, sizeof(*timeout));
                }
+/*             printf("next %ld.%06ld  now %ld.%06ld  --> timeout %ld.%06ld\n", */
+/*                    last.tv_sec, last.tv_nsec/1000, */
+/*                    now.tv_sec, now.tv_nsec/1000, */
+/*                    timeout->tv_sec, timeout->tv_nsec/1000); */
        } else if (opt.timeout_ms != 0) {
                timeout->tv_sec = opt.timeout_ms/1000;
                timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
@@ -596,11 +604,12 @@ void *measure_thread(void *arg)
                SEND();
 
        get_tstamp(&stats.tic);
-
+       ret = 0;
        while (!finish_flag &&
               (opt.count == 0 || count < opt.count || msg_in_progress != 0)) {
 
-               get_next_timeout(&timeout);
+               get_next_timeout(&timeout, ret == 0);
+               //printf("timeout %ld.%06ld\n", timeout.tv_sec, timeout.tv_nsec/1000);
                //printf("ppoll"); fflush(stdout);
                ret = ppoll(pfd, num_interfaces, &timeout, NULL);
                //printf("=%d\n", ret);