co-op should be more stable as it doesn't abort threads, which can trigger virtual machine instability
This change will be invisible to users as script DLLs are recompiled automatically where necessary, though the change won't take affect until the next simulator restart.
This change has no effect on existing script state.
If you want to continue using abort, set ScriptStopStrategy = abort in the [XEngine] section of OpenSim.ini
We have to do this since we can't unload existing DLLs if they're all in the same AppDomain.
But we can still update the underlying DLL which will be used in the next simulator session.
SmartThreadPool code comes from http://www.codeproject.com/Articles/7933/Smart-Thread-Pool
This version implements thread abort (via WorkItem.Cancel(true)), threadpool naming, max thread stack, etc. so we no longer need to manually patch those.
However, two changes have been made to stock 2.2.3.
Major change: WorkItem.Cancel(bool abortExecution) in our version does not succeed if the work item was in progress and thread abort was not specified.
This is to match previous behaviour where we handle co-operative termination via another mechanism rather than checking WorkItem.IsCanceled.
Minor change: Did not add STP's StopWatch implementation as this is only used WinCE and Silverlight and causes a build clash with System.Diagnostics.StopWatch
The reason for updating is to see if this improves http://opensimulator.org/mantis/view.php?id=6557 and http://opensimulator.org/mantis/view.php?id=6586
Moves the noise co-op start/stop debug log messages to only display if xengine debug level >= 1
Logs which stop strategy is being used (abort or co-op)
Adjusts some other logging to remove not very useful stuff
This is to eliminate disruption until co-op termination has been well-tested.
In non co-op mode, XEngine will continue to load DLLs of the existing Script class and the new XEngineScript class.
Moving to co-op mode still requires existing script DLL deletion to force recompilation, either manually or by setting DeleteScriptsOnStartup = true for one run.
This change also means that scripts which fail to initialize do not still show up as running scripts.
This involves inserting opensim_reserved_CheckForCoopTermination() calls in lsl -> c# translation at any place where the script could be in a loop with no wait calls.
These places are for, while, do-while, label, user function call and manual event function call.
Call goes through to an XEngineScriptBase which extends ScriptBase.
IEngine is extended to supply necessary engine-specific parent class references and constructor parameters to Compiler.
Unfortunately, since XEngineScriptBase has to be passed WaitHandle in its constructor, older compiled scripts will fail to load with an error on the OpenSim console.
Such scripts will need to be recompiled, either by removing all *.dll files from the bin/ScriptEngines/<region-id> or by setting DeleteScriptsOnStartup = true in [XEngine] for one run.
Automatic recompilation may be implemented in a later commit.
This feature should not yet be used, default remains termination with Thread.Abort() which will work as normal once scripts are recompiled.
This makes use of EventWaitHandles since various web references indicate that Thread.Interrupt() can also cause runtime instability.
If co-op termination is enabled, then termination sets the wait handle instead of waiting for a timeout before possibly aborting the thread.
This allows the script to cleanly terminate if it's in a llSleep/LL function delay or the next time it enters such a wait without any timeout period.
Co-op termination is not yet testable since checking for termination request within loops that never trigger a wait is not yet implemented.
This commit, unlike 1b5c41c, passes the wait handle as an extra parameter through IScript.Initialize() instead of passing IScriptInstance itself.
This makes use of EventWaitHandles since various web references indicate that Thread.Interrupt() can also cause runtime instability.
If co-op termination is enabled, then termination sets the wait handle instead of waiting for a timeout before possibly aborting the thread.
This allows the script to cleanly terminate if it's in a llSleep/LL function delay or the next time it enters such a wait without any timeout period.
Co-op termination is not yet testable since checking for termination request within loops that never trigger a wait is not yet implemented.
This is to allow the future co-operative script thread terminate feature to detect and act upon termination requests.
This splits the assembly and state loading out from the ScriptInstance() constructor to a separate Load() method
in order to facilititate continued script logic regression testing.
As with script stop (via llDie()) aborting other scripts event threads, llResetOtherScript() can also abort any current event thread on another script.
On mono 2.6, 2.10 and possibly later this may cause locking problems in certain code areas.
This commit reuses the recently introduced [XEngine] WaitForEventCompletionOnScriptStop to make this a 1 sec timeout, rather than 0 secs.
Default is 1000, as has previously been the case.
This parameter exists for further debug work concerning mono 2.10 crashes that may be related to locks not being removed on Thread.Abort
This is slightly different in that SetCurrentCulture() does not use overridden settings if the system culture matches en-US but some settings there have been changed.
This is what we want - we do not want to use any system overriden settings.
This is fired when all regions are ready or when at least one region becomes not ready.
Recently added EventManager.OnRegionReady becomes OnRegionReadyStatusChange to match OnLoginsEnabledStatusChange
The encodings are thread-safe and already used in such a manner in other places.
This isn't done where Byte Order Mark output is suppressed, since Encoding.UTF8 is constructed to output the BOM.
This is only currently meant for use by regression tests that don't have any issues if XEngine is started up quickly, since no other operations will be occuring simultaneously.
Therefore, this is not yet documented externally.
This is to avoid the worst of the problems in mono 2.6, 2.10 where an aborted thread does not always release all its locks.
This very short grace period is identical to the existing behaviour when a script is removed from the scene.
This is to take account of situations where the user was intending to specify a script engine using colon using its default language.
This probably generates few false positive as scripts are less likely to end a first line colon with a comment for other purposes.
This works by only posting the "Selected engine unavailable" message if we're falling back on XEngine and the language is one handled by XEngine.
In cases where the language is not handled or not allowed, the user will still be notified by the later compiler error.
This avoids the overwhelming majority of false positives where the first line contains a : for other reasons (e.g. source control systems, vim settings, etc.)
Ultimately, I think it would be better to detect script language/engine with a mechanism that didn't just rely on : detection (e.g like #! in unix scripts).
Justin Clark-Casey (justincc)