check timeout on delivery

prrt/proto/stores/packetDeliveryStore.c

@@ -99,8 +99,11 @@ PrrtPacket *PrrtPacketDeliveryStore_get_packet_timedwait(PrrtPacketDeliveryStore
 
 PrrtPacket *PrrtPacketDeliveryStore_get_packet(PrrtPacketDeliveryStore *store, prrtTimestamp_t start, prrtTimestamp_t stop) {
     PrrtPacket *packet = NULL;
+    bool timed_out;
     
     check(pthread_mutex_lock(&store->lock) == EXIT_SUCCESS, "Lock failed.");
+    do {
+        timed_out = false;
         
         if (start > stop) {
             packet = BPTree_get_first_in_range(store->tree, (BPTreeKey_t) start, TIMESTAMP_SPACE - 1);
@@ -113,8 +116,15 @@ PrrtPacket *PrrtPacketDeliveryStore_get_packet(PrrtPacketDeliveryStore *store, p
         
         if(packet != NULL) {
             store->tree = BPTree_delete(store->tree, PrrtDataPacket_packet_timeout(packet));
+            prrtTimestamp_t now = PrrtClock_get_current_time_us();
+            if (PrrtTimestamp_cmp(now, PrrtDataPacket_packet_timeout(packet)) > 0) {
+                timed_out = true;
+                PrrtPacket_destroy(packet);
+                packet = NULL;
+            }
         }
         
+    } while (timed_out);
     check(pthread_mutex_unlock(&store->lock) == EXIT_SUCCESS, "Unlock failed.");
 
     return packet;