0003363: Avatar becomes stuck and sim crashes running in Grid Mode

Notes
(0010228) TerrorBite (reporter) 2009-03-30 01:44	I recently saw a similar bug on my sim running in sandbox mode. The avatar was crossing regions while flying, then as soon as the new region was entered, began to drift uncontrollably across the region before crossing the edge of the sim. As soon as this occured the client began producing error dialogs and the NonFinite Avatar Position error was printed multiple times by the simulator along with some exceptions. Here's a sample: 22:27:33 - [PHYSICS]: Collection was modified;enumeration operation may not execute., Boolean MoveNext(), System.InvalidOperationException: Collection was modif ied;enumeration operation may not execute. at System.Collections.Generic.List`1+Enumerator[OpenSim.Region.Physics.OdePlugin.OdeCharacter].MoveNext () [0x00000] at OpenSim.Region.Physics.OdePlugin.OdeScene.collision_optimized (Single timeStep) [0x00000] at OpenSim.Region.Physics.OdePlugin.OdeScene.Simulate (Single timeStep) [0x00000] 22:27:33 - [Scene]: Failed with exception System.NullReferenceException: Objectreference not set to an instance of an object at Ode.NET.d.BodyGetPosition (IntPtr body) [0x00000] at OpenSim.Region.Physics.OdePlugin.OdeCharacter.UpdatePositionAndVelocity () [0x00000] at OpenSim.Region.Physics.OdePlugin.OdeScene.Simulate (Single timeStep) [0x00000] at OpenSim.Region.Framework.Scenes.SceneGraph.UpdatePhysics (Double elapsed) [0x00000] at OpenSim.Region.Framework.Scenes.Scene.Update () [0x00000] On Region: Zion 22:27:33 - [AVATAR]: NonFinite Avatar position detected... Reset Position. Mantis this please. Error# 9999902 22:27:34 - [AVATAR]: NonFinite Avatar position detected... Reset Position. Mantis this please. Error# 9999902 A few minutes after this, the server hard-crashed (kernel panic) and had to be rebooted. It seems the avatar was still active in the sim even after killing the client. Simulator: OpenSimulator Server 0.6.3.8862, 9 regions in 1 simulator, running in sandbox mode Environment: Mono 1.9.1 running on Ubuntu 8.10 Server Hardware: AMD Athlon(tm) XP 1600+ @ 1400MHz, 1GB RAM

(0010231) TerrorBite (reporter) 2009-03-30 06:33	I should add to the above, that I'm using the ODE physics engine. (Bug 0003328 is a duplicate of this?)

(0010232) Teravus (administrator) 2009-03-30 06:38	Collection was modified;enumeration operation may not execute. at System.Collections.Generic.List`1+Enumerator[OpenSim.Region.Physics.OdePlugin.OdeCharacter] at OpenSim.Region.Physics.OdePlugin.OdeScene.collision_optimized Implies that something is trying to modify the character list while collisions are occurring. Obviously, this shouldn't be happening.

(0010234) svn (developer) 2009-03-30 07:10	teravus committed related code in r8929 * Fixing thread safety of avatar adding and removing from the Physics Scene in the ODEPlugin * This may help one of the symptoms or mantis 3363 , however it probably won't solve the occasional NonFinite Avatar Position detected.. issues that some people see. That is probably an entirely different issue(NaN). see more at - http://opensimulator.org/cgi-bin/viewvc.cgi?view=rev&revision=8929 [^]

(0010456) Sypher (reporter) 2009-04-06 07:02	The problem is also occurring in r9008 on Linux-64 (Mono version: 1.9.1). The messages coming in quite fast and causes the whole grid to come to a standstill.

(0010696) Teravus (administrator) 2009-04-13 19:05	Teravus Committed Code related to this issue in revision 9131. Testers, give it a try.

(0010734) M1sha (reporter) 2009-04-15 11:36	19:30:33 - [PHYSICS]: Avatar Position is non-finite! 19:30:33 - [PHYSICS]: Collection was modified; enumeration operation may not exe cute., Void ThrowInvalidOperationException(System.ExceptionResource), System.Inv alidOperationException: Collection was modified; enumeration operation may not e xecute. Above observed on svn 9145, Vista, ODEPhysics while trying to replicate Mantis 3363 on a standalone.

(0011915) AngeloG (reporter) 2009-06-03 11:00	I'm having this problem on Windows XP.

Issue History
Date Modified	Username	Field	Change
2009-03-30 01:13	hera	New Issue
2009-03-30 01:13	hera	SVN Revision	=> 0
2009-03-30 01:13	hera	Run Mode	=> Grid (Multiple Regions per Sim)
2009-03-30 01:13	hera	Physics Engine	=> ODE
2009-03-30 01:13	hera	Environment	=> Mono / Linux32
2009-03-30 01:13	hera	Mono Version	=> 2.0.1
2009-03-30 01:44	TerrorBite	Note Added: 0010228
2009-03-30 06:27	Teravus	Category	[GRID] Grid Server => [REGION] Physics Engines
2009-03-30 06:27	Teravus	Issue Monitored: Teravus
2009-03-30 06:33	TerrorBite	Note Added: 0010231
2009-03-30 06:38	Teravus	Note Added: 0010232
2009-03-30 07:10	svn	Checkin
2009-03-30 07:10	svn	Note Added: 0010234
2009-03-30 10:06	Jamenai	Relationship added	has duplicate 0003328
2009-03-31 19:08	nlin	Issue Monitored: nlin
2009-04-05 20:07	dmiles	Relationship added	has duplicate 0003407
2009-04-05 20:08	dmiles	Relationship added	has duplicate 0003349
2009-04-05 20:09	dmiles	Relationship added	has duplicate 0002919
2009-04-05 20:10	dmiles	Relationship added	has duplicate 0001729
2009-04-05 20:15	dmiles	Issue Monitored: dmiles
2009-04-06 07:02	Sypher	Note Added: 0010456
2009-04-06 07:04	Sypher	Issue Monitored: Sypher
2009-04-13 19:05	Teravus	Note Added: 0010696
2009-04-15 11:36	M1sha	Note Added: 0010734
2009-06-03 11:00	AngeloG	Note Added: 0011915