If we're not receiving packets with multiple threads (m_asyncPacketHandling) then this is critical since it will limit the number of incoming UDP requests that the region can handle and affects packet loss.
If m_asyncPacketHandling then this is less critical though a long process will increase the scope for threads to race.
This is an experimental stat which may be changed.
This appears to improve cpu usage since launching a new thread is more expensive than performing a small amount of inline logic.
However, needs testing at scale.
On Windows, concurrent multi-threaded processing of inbound UDP somehow allows different data input processing to interfere with each other.
Possibly the endpoint reference is being switched, though I don't yet know the mechanism. Not seen on Mono.
Also resolveable by setting RecyclePackets = false or RecycleBaseUDPPackets = false in [PacketPool]
Or async_packet_handling = false in [ClientStack.LindenUDP]
For now, will simply disable this particular pooling though will revisit this issue.
In response to http://opensimulator.org/mantis/view.php?id=6468
This introduces a pull stat type in addition to the push stat type.
A pull stat takes a method on construction which knows how to update the stat on request.
In this way, special interfaces for pull stat collection are not necessary.
Even when an avatar is standing still, it's sending in a constant stream of AgentUpdate packets that the client creates new UDPPacketBuffer objects to handle.
This option pools those objects. This reduces memory churn.
Currently off by default. Works but the scope can be expanded.
This is controlled via the "debug lludp start <in|out|all>" and "debug lludp stop <in|out|all>" region console commands.
The command "debug lludp status" will show current status.
Justin Clark-Casey (justincc)