When an object is removed, its scripts are stopped and then the thread running them is aborted if stop takes too long.
However, it appears that aborting a thread at just the wrong moment when it is obtaining a ReaderWriterLockSlim lock can leave this lock in an inconsistent state.
One symptom of this is that mono leaps to 100% cpu and a vm thread dump reveals lots of threads waiting for a ReaderWriterLockSlim lock without any thread actually holding it.
This is probably the same problem as encountered originally in commit 12cebb12
This commit looks to plaster this problem by putting lock obtaining methods inside finally blocks which should be uninterruptible by thread aborts.
* Initialize the LLClientView prim full update queue to the number of prims in the scene for a big performance boost
* Reordered some comparisons on hot code paths for a minor speed boost
* Removed an unnecessary call to the expensive DateTime.Now function (if you *have* to get the current time as opposed to Environment.TickCount, always use DateTime.UtcNow)
* Don't fire the queue empty callback for the Resend category
* Run the outgoing packet handler thread loop for each client synchronously. It seems like more time was being spent doing the execution asynchronously, and it made deadlocks very difficult to track down
* Rewrote some expensive math in LandObject.cs
* Optimized EntityManager to only lock on operations that need locking, and use TryGetValue() where possible
* Only update the attachment database when an object is attached or detached
* Other small misc. performance improvements
OpenSim.Region.Environment into a "framework" part and a modules only
part. This first changeset refactors OpenSim.Region.Environment.Scenes,
OpenSim.Region.Environment.Interfaces, and OpenSim.Region.Interfaces
into OpenSim.Region.Framework.{Interfaces,Scenes} leaving only region
modules in OpenSim.Region.Environment.
The next step will be to move region modules up from
OpenSim.Region.Environment.Modules to OpenSim.Region.CoreModules and
then sort out which modules are really core modules and which should
move out to forge.
I've been very careful to NOT BREAK anything. i hope i've
succeeded. as this is the work of a whole week i hope i managed to
keep track with the applied patches of the last week --- could any of
you that did check in stuff have a look at whether it survived? thx!
Justin Clark-Casey (justincc)