Often, by the time the UDPServer realizes that an entity update packet
has not been acknowledged, there is a newer update for the same entity
already queued up or there is a higher priority update that should be
sent first. This patch eliminates 1:1 packet resends for unacked entity
update packets. Insteawd, unacked update packets are decomposed into the
original entity updates and those updates are placed back into the
priority queues based on their new priority but the original update
timestamp. This will generally place them at the head of the line to be
put back on the wire as a new outgoing packet but prevents the resend
queue from filling up with multiple stale updates for the same entity.
This new approach takes advantage of the UDP nature of the Linden protocol
in that the intent of a reliable update packet is that if it goes
unacknowledge, SOMETHING has to happen to get the update to the client.
We are simply making sure that we are resending current object state
rather than stale object state.
Additionally, this patch includes a generalized callback mechanism so
that any caller can specify their own method to call when a packet
expires without being acknowledged. We use this mechanism to requeue
update packets and otherwise use the UDPServer default method of just
putting expired packets in the resend queue.
Often, by the time the UDPServer realizes that an entity update packet
has not been acknowledged, there is a newer update for the same entity
already queued up or there is a higher priority update that should be
sent first. This patch eliminates 1:1 packet resends for unacked entity
update packets. Insteawd, unacked update packets are decomposed into the
original entity updates and those updates are placed back into the
priority queues based on their new priority but the original update
timestamp. This will generally place them at the head of the line to be
put back on the wire as a new outgoing packet but prevents the resend
queue from filling up with multiple stale updates for the same entity.
This new approach takes advantage of the UDP nature of the Linden protocol
in that the intent of a reliable update packet is that if it goes
unacknowledge, SOMETHING has to happen to get the update to the client.
We are simply making sure that we are resending current object state
rather than stale object state.
Additionally, this patch includes a generalized callback mechanism so
that any caller can specify their own method to call when a packet
expires without being acknowledged. We use this mechanism to requeue
update packets and otherwise use the UDPServer default method of just
putting expired packets in the resend queue.
this appears to cause problems with the system timer resolution.
This caused a problem with tokens going into the root throttle as
bursts leading to some starvation.
Also changed EnqueueOutgoing to always queue a packet if there
are already packets in the queue. Ensures consistent ordering
of packet sends.
From pure code inspection, it looks like the uuid gatherer may get most asset uuids because the scene object serializer naively pulls non-root parts from all contained scene objects into one mega-object. However, root part uuids may well still be missing, and there may be other odd artifacts from this bug.
It appears that storing the size of the coalescence and the offsets is redundant, since one can work out this information from the position data already in the scene object groups.
Justin Clark-Casey (justincc)