ConcurrentModificationException in YamlThingProvider.retryCreateThing

[lolodomo]

At first startup of 5.2 M6:

06:59:17.959 [WARN ] [ommon.WrappedScheduledExecutorService] - Scheduled runnable ended with an exception:
java.util.ConcurrentModificationException: null
        at java.util.ArrayList$ArrayListSpliterator.tryAdvance(Unknown Source) ~[?:?]
        at java.util.stream.ReferencePipeline.forEachWithCancel(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.copyIntoWithCancel(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[?:?]
        at java.util.stream.FindOps$FindOp.evaluateSequential(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[?:?]
        at java.util.stream.ReferencePipeline.findFirst(Unknown Source) ~[?:?]
        at org.openhab.core.model.yaml.internal.things.YamlThingProvider.retryCreateThing(YamlThingProvider.java:337) ~[?:?]
        at org.openhab.core.model.yaml.internal.things.YamlThingProvider.lambda$28(YamlThingProvider.java:306) ~[?:?]
        at java.lang.Iterable.forEach(Unknown Source) ~[?:?]
        at org.openhab.core.model.yaml.internal.things.YamlThingProvider.lambda$26(YamlThingProvider.java:305) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(Unknown Source) ~[?:?]
        at java.util.stream.ReferencePipeline$2$1.accept(Unknown Source) ~[?:?]
        at java.util.concurrent.ConcurrentHashMap$KeySpliterator.forEachRemaining(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[?:?]
        at java.util.stream.ReferencePipeline.forEach(Unknown Source) ~[?:?]
        at org.openhab.core.model.yaml.internal.things.YamlThingProvider.thingHandlerFactoryAdded(YamlThingProvider.java:299) ~[?:?]
        at org.openhab.core.model.yaml.internal.things.YamlThingProvider.lambda$24(YamlThingProvider.java:282) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(Unknown Source) ~[?:?]
        at java.util.stream.ReferencePipeline$2$1.accept(Unknown Source) ~[?:?]
        at java.util.Spliterators$ArraySpliterator.forEachRemaining(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[?:?]
        at java.util.stream.ReferencePipeline.forEach(Unknown Source) ~[?:?]
        at org.openhab.core.model.yaml.internal.things.YamlThingProvider.onReadyMarkerAdded(YamlThingProvider.java:281) ~[?:?]
        at org.openhab.core.internal.service.ReadyServiceImpl.lambda$0(ReadyServiceImpl.java:54) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(Unknown Source) ~[?:?]
        at java.util.stream.ReferencePipeline$3$1.accept(Unknown Source) ~[?:?]
        at java.util.stream.ReferencePipeline$2$1.accept(Unknown Source) ~[?:?]
        at java.util.HashMap$EntrySpliterator.forEachRemaining(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(Unknown Source) ~[?:?]
        at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[?:?]
        at java.util.stream.ReferencePipeline.forEach(Unknown Source) ~[?:?]
        at org.openhab.core.internal.service.ReadyServiceImpl.notifyTrackers(ReadyServiceImpl.java:78) ~[?:?]
        at org.openhab.core.internal.service.ReadyServiceImpl.markReady(ReadyServiceImpl.java:54) ~[?:?]
        at org.openhab.core.config.core.xml.osgi.XmlDocumentBundleTracker.registerReadyMarker(XmlDocumentBundleTracker.java:417) ~[?:?]
        at org.openhab.core.config.core.xml.osgi.XmlDocumentBundleTracker.finishBundle(XmlDocumentBundleTracker.java:360) ~[?:?]
        at org.openhab.core.config.core.xml.osgi.XmlDocumentBundleTracker.processBundle(XmlDocumentBundleTracker.java:383) ~[?:?]
        at org.openhab.core.config.core.xml.osgi.XmlDocumentBundleTracker$2.run(XmlDocumentBundleTracker.java:345) ~[?:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:?]
        at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:?]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) ~[?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) ~[?:?]
        at java.lang.Thread.run(Unknown Source) [?:?]

This error is not systematic, I saw it only once, at very first startup of OH.

[Nadahar]

It's clearly a thread-safety issue, they only bite "randomly", but the bug real anyway 😉