[automation] Script engines now unloaded if replaced, and closed if AutoCloseable

[jpg0]

This change:

• Prevents scripts (and their associated engines) from replacing themselves without proper unloading
• Closes any engines with implement AutoCloseable

(Required to fix openhab/openhab-addons#11952)

Signed-off-by: Jonathan Gilbert jpg@trillica.com

[wborn]

It's nice to be able to close script engine resources without having to restart the runtime. 👍

[digitaldan]

@jpg0 i mentioned this in openhab/openhab-addons#11830 , but after digging into the error, i think its caused by this change, as mentioned in the other PR, I'm getting this error anytime a rule file is updated

19:37:25.062 [INFO ] [.rulesupport.loader.ScriptFileWatcher] - Loading script '/Users/daniel/openhab-main/openhab-3.3.0-SNAPSHOT/conf/automation/js/test.js'
19:37:25.062 [WARN ] [ommon.WrappedScheduledExecutorService] - Scheduled runnable ended with an exception:
java.lang.IllegalStateException: The Context is already closed.
	at com.oracle.truffle.polyglot.PolyglotEngineException.illegalState(PolyglotEngineException.java:129) ~[?:?]
	at com.oracle.truffle.polyglot.PolyglotContextImpl.checkClosed(PolyglotContextImpl.java:1025) ~[?:?]
	at com.oracle.truffle.polyglot.PolyglotContextImpl.enterThreadChanged(PolyglotContextImpl.java:608) ~[?:?]
	at com.oracle.truffle.polyglot.PolyglotEngineImpl.enterCached(PolyglotEngineImpl.java:1885) ~[?:?]
	at com.oracle.truffle.polyglot.PolyglotEngineImpl.enterIfNeeded(PolyglotEngineImpl.java:1813) ~[?:?]
	at com.oracle.truffle.polyglot.PolyglotValueDispatch.hostEnter(PolyglotValueDispatch.java:1228) ~[?:?]
	at com.oracle.truffle.polyglot.PolyglotContextImpl.getBindings(PolyglotContextImpl.java:966) ~[?:?]
	at com.oracle.truffle.polyglot.PolyglotContextDispatch.getBindings(PolyglotContextDispatch.java:97) ~[?:?]
	at org.graalvm.polyglot.Context.getBindings(Context.java:540) ~[?:?]
	at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.invokeFunction(GraalJSScriptEngine.java:548) ~[?:?]
	at org.openhab.automation.jsscripting.internal.scriptengine.DelegatingScriptEngineWithInvocableAndAutocloseable.invokeFunction(DelegatingScriptEngineWithInvocableAndAutocloseable.java:121) ~[?:?]
	at org.openhab.automation.jsscripting.internal.scriptengine.InvocationInterceptingScriptEngineWithInvocableAndAutoCloseable.invokeFunction(InvocationInterceptingScriptEngineWithInvocableAndAutoCloseable.java:119) ~[?:?]
	at org.openhab.automation.jsscripting.internal.scriptengine.DelegatingScriptEngineWithInvocableAndAutocloseable.invokeFunction(DelegatingScriptEngineWithInvocableAndAutocloseable.java:121) ~[?:?]
	at org.openhab.automation.jsscripting.internal.scriptengine.InvocationInterceptingScriptEngineWithInvocableAndAutoCloseable.invokeFunction(InvocationInterceptingScriptEngineWithInvocableAndAutoCloseable.java:119) ~[?:?]
	at org.openhab.core.automation.module.script.internal.ScriptEngineManagerImpl.removeEngine(ScriptEngineManagerImpl.java:207) ~[?:?]
	at org.openhab.core.automation.module.script.internal.ScriptEngineManagerImpl.createScriptEngine(ScriptEngineManagerImpl.java:127) ~[?:?]
	at org.openhab.core.automation.module.script.rulesupport.loader.ScriptFileWatcher.createAndLoad(ScriptFileWatcher.java:229) ~[?:?]
	at org.openhab.automation.jsscripting.internal.fs.watch.JSScriptFileWatcher.createAndLoad(JSScriptFileWatcher.java:55) ~[?:?]
	at org.openhab.core.automation.module.script.rulesupport.loader.ScriptFileWatcher.importFile(ScriptFileWatcher.java:213) ~[?:?]
	at org.openhab.core.automation.module.script.rulesupport.loader.ScriptFileWatcher.lambda$2(ScriptFileWatcher.java:205) ~[?:?]
	at java.util.Optional.ifPresent(Optional.java:183) ~[?:?]
	at org.openhab.core.automation.module.script.rulesupport.loader.ScriptFileWatcher.importFileWhenReady(ScriptFileWatcher.java:203) ~[?:?]
	at org.openhab.core.automation.module.script.rulesupport.loader.ScriptFileWatcher.processWatchEvent(ScriptFileWatcher.java:180) ~[?:?]
	at org.openhab.automation.jsscripting.internal.fs.watch.JSScriptFileWatcher.processWatchEvent(JSScriptFileWatcher.java:49) ~[?:?]
	at org.openhab.core.service.WatchQueueReader.lambda$3(WatchQueueReader.java:319) ~[?:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) ~[?:?]
	at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?]
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304) ~[?:?]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
	at java.lang.Thread.run(Thread.java:829) [?:?]

I see this PR is closing the script engine (delegate), but without digging in more, it seems like this is not cleaning it up correctly and the closed script engine is continued to be used?

[jpg0]

@digitaldan I've submitted a (trivial, tbh) PR to remove them here: #2706

My limited testing seemed to confirm that this fixed the issue.