Eclipse Community Forums: TMF (Xtext) » XtextReconcilerJob popup error (start

Home » Modeling » TMF (Xtext) » XtextReconcilerJob popup error (start > length)

XtextReconcilerJob popup error (start > length) [message #1790057]

Mon, 04 June 2018 06:03

Eclipse User

Hello,

With Xtext 2.10, I sometimes get a popup error: XtextReconcilerJob start > length when I type something invalid with my language.

I tried to update to Xtext 2.14, but I still get the popup.

The problem is the error seems not related with my source code. The stack trace only mention xtext, so It is difficult for me to fix the problem.

Here is the stack trace associated:

!ENTRY org.eclipse.core.jobs 4 2 2018-06-04 11:42:52.343
!MESSAGE An internal error occurred during: "XtextReconcilerJob".
!STACK 0
java.lang.StringIndexOutOfBoundsException: start > length()
at java.lang.AbstractStringBuilder.replace(AbstractStringBuilder.java:853)
at java.lang.StringBuilder.replace(StringBuilder.java:262)
at org.eclipse.xtext.ui.editor.reconciler.ReconcilerReplaceRegion$Builder.add(ReconcilerReplaceRegion.java:89)
at org.eclipse.xtext.ui.editor.reconciler.XtextReconciler.getMergedReplaceRegion(XtextReconciler.java:405)
at org.eclipse.xtext.ui.editor.reconciler.XtextReconciler.doRun(XtextReconciler.java:434)
at org.eclipse.xtext.ui.editor.reconciler.XtextReconciler.access$3(XtextReconciler.java:430)
at org.eclipse.xtext.ui.editor.reconciler.XtextReconciler$1.process(XtextReconciler.java:364)
at org.eclipse.xtext.ui.editor.reconciler.XtextReconciler$1.process(XtextReconciler.java:1)
at org.eclipse.xtext.util.concurrent.IUnitOfWork$Void.exec(IUnitOfWork.java:37)
at org.eclipse.xtext.resource.OutdatedStateManager.exec(OutdatedStateManager.java:91)
at org.eclipse.xtext.ui.editor.model.XtextDocument$XtextDocumentLocker.modify(XtextDocument.java:433)
at org.eclipse.xtext.ui.editor.model.XtextDocument.internalModify(XtextDocument.java:166)
at org.eclipse.xtext.ui.editor.reconciler.XtextReconciler.run(XtextReconciler.java:361)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

How to fix this problem ? Any help would be appreciated.

Best regards,

Re: XtextReconcilerJob popup error (start > length) [message #1790059 is a reply to message #1790057]

Mon, 04 June 2018 06:27

Eclipse User

Could you provide a minimal grammar and model that reproduced this

Re: XtextReconcilerJob popup error (start > length) [message #1790061 is a reply to message #1790059]

Mon, 04 June 2018 06:44

Eclipse User

looks like https://bugs.eclipse.org/bugs/show_bug.cgi?id=471849 https://bugs.eclipse.org/bugs/show_bug.cgi?id=413290

Re: XtextReconcilerJob popup error (start > length) [message #1790064 is a reply to message #1790061]

Mon, 04 June 2018 07:12

Eclipse User

Hi

I've seen similar things and decided that it was failure to observe the IUnitOfText lockout correctly. Wasn't sure whether it was my bad code or Xtext's. My suspicion is that the the integrity of the original design has slipped as threading has evolved. It is certainly not uncommon for editors to get into a stale state that needs a well-chosen edit to force a reparse.

Regards

Ed Willink

Re: XtextReconcilerJob popup error (start > length) [message #1790065 is a reply to message #1790064]

Mon, 04 June 2018 07:25

Eclipse User

this could either be a bug in the xtext reconciler or a race. for both it would be helpful to have reproducible steps

Re: XtextReconcilerJob popup error (start > length) [message #1790076 is a reply to message #1790065]

Mon, 04 June 2018 08:30

Eclipse User

Thanks gentlemen for your answers.

Unfortunately I can't share a minimal grammar and model in my context. I should have mention this in my post, and I know I will be quite diffucult to progress on this issue without reproducible steps.
Indeed, https://bugs.eclipse.org/bugs/show_bug.cgi?id=471849 https://bugs.eclipse.org/bugs/show_bug.cgi?id=413290 seem to be the same problem.

Best regards,

Re: XtextReconcilerJob popup error (start > length) [message #1790077 is a reply to message #1790076]

Mon, 04 June 2018 08:37

Eclipse User

=> you need to analyze locally.
-do this happen when you edit small files or bug files
-does it happen if you edit slow or edit false
-does it happen if you expand the length (type) or if you shrink (delete)
-if you have a look at the code (e.g. ReconcilerReplaceRegion) and trace back the data: where does the wrong data come from?
-is in org.eclipse.xtext.ui.editor.reconciler.XtextReconciler.getMergedReplaceRegion(XtextResource) the resource text ok or are the events data outdated?

Re: XtextReconcilerJob popup error (start > length) [message #1790087 is a reply to message #1790077]

Mon, 04 June 2018 11:10

Eclipse User

Quote:

-do this happen when you edit small files or bug files

It happens with small files. I never tested with big files, and big files have no real meaning in my context.

Quote:

-does it happen if you edit slow or edit false

It happens when I modify a valid expression to an invalid expression, and I edit slow. Error markers appear after few seconds, and then when I try to validate my expression, the popup appears.

Quote:

-does it happen if you expand the length (type) or if you shrink (delete)

It happens when I modify a valid expression to an invalid expression that is longer than the previous valid one. If the invalid expression is smaller than the previous valid one, the popup is not raised.

Quote:

-if you have a look at the code (e.g. ReconcilerReplaceRegion) and trace back the data: where does the wrong data come from?

I don't know.

Quote:

-is in org.eclipse.xtext.ui.editor.reconciler.XtextReconciler.getMergedReplaceRegion(XtextResource) the resource text ok or are the events data outdated?

The text seems ok.

Re: XtextReconcilerJob popup error (start > length) [message #1790088 is a reply to message #1790087]

Mon, 04 June 2018 11:19

Eclipse User

as is said: this needs to be debugged and therefore to be reproduced or debugged there where it occurs

Re: XtextReconcilerJob popup error (start > length) [message #1790089 is a reply to message #1790088]

Mon, 04 June 2018 11:45

Eclipse User

Hi

I debugged it once in situ. It was 'impossible' demonstrating that a concurrency had occurred. I think it somehow needs to be instrumented by Xtext. I don't recall an Xtext exception ever being thrown because I didn't use a IUnitOfWork correctly, rather Sebastian or Jan or ... kindly pointed out the error of my ways in a bug report / forum message.

While I wouldn't particularly advocate the nannying of EMF Transaction within Papyrus that insists on an appropriate Modify Transaction before allowing mutable EMF operations, it might help if Xtext was able to assert that certain critical operations are within a correct IUnitOfWork. Perhaps a debug variant of Xtext could leverage EMF Transaction. to demonstrate that the primary Xtext functionality is as intended, and optionally allow developers to check their extensions.

Without instrumentation, this kind of concurrency bug will only be found by luck or insightful review.

Regards

Ed Willink

Previous Topic:	Reference other Xtext model
Next Topic:	LanguageServer with Apache HTTP Client, endless wait on read

Goto Forum:

-=] Back to Top [=-

Current Time: Wed Jun 25 02:10:49 EDT 2025

.:: Contact :: Home ::.

Breadcrumbs

Sign up to our Newsletter