This message is seen on V2 if one attempts to quickly re-teleport from a source region where one had previously teleported to a non-neighbour and back within 15 secs.
The solution here is for the user to wait a short while.
This message can also be seen on any teleport protocol if one recieves multiple teleport attempts simultaneously. Probably still useful here to help identify misbehaving scripts.
This approach has problems if a client quits without sending a proper logout but then reconnects before the connection is closed due to inactivity.
In this case, the DoNotCloseAfterTeleport was wrongly set.
The simplest approach is to close child agents on teleport as quickly as possible so that races are very unlikely to occur
Hence, this code now closes child agents as the first action after a sucessful teleport.
The root cause was that v2 was only closing neighbour agents if the root connection also needed a close.
However, fixing this requires the neighbour regions also detect when they should not close due to re-teleports re-establishing the child connection.
This involves restructuring the code to introduce a scene presence state machine that can serialize the different add and remove client calls that are now possible with the late close of the
This commit appears to fix these issues and improve teleport, but still has holes on at least quick reteleporting (and possibly occasionally on ordinary teleports).
Also, has not been completely tested yet in scenarios where regions are running on different simulators
This stops OpenSimulator still trying to teleport the user if they hit cancel on the teleport screen or closed the viewer whilst the protocol was trying to create an agent on the remote region.
Ideally, the code may also attempt to tell the destination simulator that the agent should be removed (accounting for issues where the destination was not responding in the first place, etc.)
- Child and root agents are only closed after 15 sec, maybe
- If the user comes back, they aren't closed, and everything is reused
- On the receiving side, clients and scene presences are reused if they already exist
- Caps are always recreated (this is where I spent most of my time!). It turns out that, because the agents carry the seeds around, the seed gets the same URL, except for the root agent coming back to a far away region, which gets a new seed (because we don't know what was its seed in the departing region, and we can't send it back to the client when the agent returns there).
This is because a returning viewer by teleport before 15 seconds are up will be disrupted by the close.
The 2 second delay is within the scope where a normal viewer would not allow a teleport back anyway.
Simulator/0.2 (V2) protocol will continue with the longer delay since this is actually the behaviour viewers get from the ll grid
and an early close causes other issues (avatar being sent to infinite locations temporarily, etc.)
This prevents an issue if the user teleports back to the neighbour simulator of a source before 15 seconds have elapsed.
This more closely emulates observed linden behaviour, though the timeout there is 50 secs and applies to all the pre-teleport agents.
Currently sticks a DoNotClose flag on ScenePresence though this may be temporary as possibly it could be incorporated into the ETM state machine
In this new protocol, and as committed before, the viewer is not sent EnableSimulator/EstablishChildCommunication for the destination. Instead, it is sent TeleportFinish directly. TeleportFinish, in turn, makes the viewer send a UserCircuitCode packet followed by CompleteMovementIntoRegion packet. These 2 packets tend to occur one after the other almost immediately to the point that when CMIR arrives the client is not even connected yet and that packet is ignored (there might have been some race conditions here before); then the viewer sends CMIR again within 5-8 secs. But the delay between them may be higher in busier regions, which may lead to race conditions.
This commit improves the process so there are are no race conditions at the destination. CompleteMovement (triggered by the viewer) waits until Update has been sent from the origin. Update, in turn, waits until there is a *root* scene presence -- so making sure CompleteMovement has run MakeRoot. In other words, there are two threadlets at the destination, one from the viewer and one from the origin region, waiting for each other to do the right thing. That makes it safe to close the agent at the origin upon return of the Update call without having to wait for callback, because we are absolutely sure that the viewer knows it is in th new region.
Note also that in the V1 protocol, the destination was getting UseCircuitCode from the viewer twice -- once on EstablishAgentCommunication and then again on TeleportFinish. The second UCC was being ignored, but it shows how we were not following the expected steps...
This is so that other callers (such as SceneCommunicationService.SendCloseChildAgentConnections() can perform all closes asynchronously without pointlessly firing another thread for local closes).
No functional change apart from elimination of unnecessary chaining of new threads.
Unfortunately fails on Nebadon's system right now. Needs investigation. May put in a temproary option for experimentation soon.
This reverts commit d87ddf50fc.
