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-rw-r--r--avahi-common/timeval.c30
1 files changed, 27 insertions, 3 deletions
diff --git a/avahi-common/timeval.c b/avahi-common/timeval.c
index e5732cd..2d0d693 100644
--- a/avahi-common/timeval.c
+++ b/avahi-common/timeval.c
@@ -23,6 +23,7 @@
#include <config.h>
#endif
+#include <pthread.h>
#include <stdlib.h>
#include <assert.h>
@@ -84,7 +85,6 @@ AvahiUsec avahi_age(const struct timeval *a) {
return avahi_timeval_diff(&now, a);
}
-
struct timeval *avahi_elapse_time(struct timeval *tv, unsigned msec, unsigned jitter) {
assert(tv);
@@ -93,8 +93,32 @@ struct timeval *avahi_elapse_time(struct timeval *tv, unsigned msec, unsigned ji
if (msec)
avahi_timeval_add(tv, (AvahiUsec) msec*1000);
- if (jitter)
- avahi_timeval_add(tv, (AvahiUsec) (jitter*1000.0*rand()/(RAND_MAX+1.0)));
+ if (jitter) {
+ static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+ static int last_rand;
+ static time_t timestamp = 0;
+
+ time_t now;
+ int r;
+
+ now = time(NULL);
+
+ pthread_mutex_lock(&mutex);
+ if (now >= timestamp + 10) {
+ timestamp = now;
+ last_rand = rand();
+ }
+
+ r = last_rand;
+
+ pthread_mutex_unlock(&mutex);
+
+ /* We use the same jitter for 10 seconds. That way our
+ * time events elapse in bursts which has the advantage that
+ * packet data can be aggegrated better */
+
+ avahi_timeval_add(tv, (AvahiUsec) (jitter*1000.0*r/(RAND_MAX+1.0)));
+ }
return tv;
}