Add some comments to compute_next_snapshot_time().

Also, move the call to gettimeofday() down to where it is needed.

diff --git a/dss.c b/dss.c
index f8a1e5132dfd3954bd2242b2f38d6deb384ffa9e..c4349a84aa9dae70f4735bd25015568d37a72379 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -175,13 +175,13 @@ static void compute_next_snapshot_time(void)
        tmp.tv_sec = x;
        tmp.tv_usec = 0;
        ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
-       gettimeofday(&now, NULL);
-       if (ret < 0 || !s)
+       if (ret < 0 || !s) /* unit_interval < tmp or no snapshot */
                goto min_sleep;
        tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
-       diff.tv_sec = s->completion_time;
+       diff.tv_sec = s->completion_time; /* completion time of the the latest snaphot */
        diff.tv_usec = 0;
        tv_add(&diff, &tmp, &next_snapshot_time);
+       gettimeofday(&now, NULL);
        if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
                goto out;
 min_sleep: