'Error in diagram web socket' when opening eclipse editor

[Mc-Hoyos]

And the stack trace:

java.nio.channels.ClosedChannelException
at org.eclipse.jetty.websocket.core.internal.WebSocketSessionState.onEof(WebSocketSessionState.java:168)
at org.eclipse.jetty.websocket.core.WebSocketCoreSession.onEof(WebSocketCoreSession.java:229)
at org.eclipse.jetty.websocket.core.WebSocketConnection.onClose(WebSocketConnection.java:209)
at org.eclipse.jetty.io.SelectorManager.connectionClosed(SelectorManager.java:363)
at org.eclipse.jetty.io.ManagedSelector$DestroyEndPoint.run(ManagedSelector.java:1095)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:999)
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.doRunJob(QueuedThreadPool.java:1229)
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1184)
at java.base/java.lang.Thread.run(Thread.java:1583)

I am trying to debug this, but since the stack trace does not point to any glsp classes I am not sure how to proceed.

[tortmayr]

Hi @Mc-Hoyos,

could you please provide additional context otherwise the error is hard to track/reproduce.|

What version of the Eclipse Integration are you using?
Are you trying to run our provided workflow-example?
Or did you integrate GLSP into your own project?

[tortmayr]

Thanks, I will use the same version and do a quick test.

[Mc-Hoyos]

To launch the editor you need to select the 'D3TestingExample.wfp' file and 'Open with -> WF+ Graphical Model Notation Editor'

[tortmayr]

First of all, you can disregard my comment regarding potential version conflicts. I double checked and only version 2.2.x and below are affected by this. 2.3.0 should work perfectly fine with 2024-12.

So, I could reproduce your issue and made an interesting discovery:
I also installed the 2.3.0 Workflow Example editor from the https://download.eclipse.org/glsp/ide/p2/releases/2.3.0/ update site.
I just wanted to check if its a generic issue or specific to your plugin.
Funnily enough after installing the Workflow editor, your Editor now also works as expected 😁:

It seems like you are missing a dependency in your plugin, that is provided by the workflow editor. I will try to narrow this down.

[Mc-Hoyos]

That is interesting indeed. So if it works locally, then my target platform seems to be OK... its when packaging that something goes amiss. Its a good starting point to investigate.

[Mc-Hoyos]

Hi @tortmayr ,

I have tried making sure both my server and editor have the same dependencies as the example projects and still getting the same error. Have you been able to investigate further? If you have any vague idea where to look I can help with the search.

[rhollom]

In my experience, this error occurs when closing the editor, not opening. The error is thrown from Jetty itself, and is benign - though annoying that it fills up the error log.
I did not find any Jetty settings to repress this, so my solution was to extend the org.eclipse.ui.statusHandlers extension point in my GLSP plugin. This handler overrides the default behavior to log errors to the Eclipse error log (and the console).

You can then check if the error is a ClosedChannelException, and ignore it:

@Override public void handle(StatusAdapter statusAdapter, int style) { if ("org.eclipse.glsp.ide.editor".equals(statusAdapter.getStatus().getPlugin())) { if (statusAdapter.getStatus().getException() instanceof ClosedChannelException) { return; } } super.handle(statusAdapter, style); }

Hope this helps.

[Mc-Hoyos]

Thanks for the tip. Sadly I get this error on opening so the editor does not actually load.

[rhollom]

I would still assert that this error comes when closing the editor/connection. So in your case this error sounds like an effect rather than the root cause. Some other error is likely occurring during initialization leading to the connection getting closed.

When you say this works with a "nested Eclipse" I assume you mean launching a separate Eclipse Application instance from your development environment? If so it sounds like an issue with the packaging/update site contents. Do you see any other errors while opening? Or if you launch Eclipse with -debug? Specifically any "bundle cannot be resolved" type errors.

I'm not sure how you're creating your update site, but here's a few other ways to debug further:

1. Open the Plug-in Registry view, find your plugin, and right click->Diagnose (you need to show advanced options to see this)
2. You could try adding your update site repo directly to your current Target Platform and see if it gives any more insight.
3. If you're building with Tycho, you could do a full product build rather than just an update site to verify things this way as well.
4. After installing your update site (and things are broken), create an Eclipse Application launch configuration and go to the Plug-ins tab. Select "Validate Plug-ins" to ensure things are resolving.
5. Try installing your update site from the command line using p2 director. The Update Site wizard in Eclipse does additional things behind the scenes to uninstall older versions/conflicts that aren't obvious. The command line p2 director is more strict and might show you what is failing.

[Mc-Hoyos]

Thanks for the detailed debug workflow. I will follow it to see if I can nail down the issue.

[Mc-Hoyos]

Some updates,

1. The plugin registry diagnose shows me a short list of plugins missing all related to glsp. However, some of the plugins it shows as missing are installed. So not sure how to use the tool further. I guess I need to just follow all the dependencies
2. The target platform could fetch all dependencies correctly.
3. Haven't tried the product build
4. Creating a run configuration didn't show any missing plugins when validating.
5. The installation went fine with the p2 director.

On a side note, installing the Workflow example did not solve my issue as it did for @tortmayr .

[arcanefoam]

Any pointers on how to follow the websocket creation to try to pin-point the reason for the failure? I have a gut feeling that it's a dependency injection gone bad, as guice loves to catch and hide injection exceptions. I have compared the dependencies and available plugins in my local runtime vs a installed runtime and as far as I can tell no dependencies are missing.

[arcanefoam]

@tortmayr I have tried to get the Workflow example to work to compare what is being installed, and I am also getting the websocket exception. I tried in a 2023-12 and a 2024-09 fresh eclipse modeling installs.

[tortmayr]

I should have time to look into this again this week.

[arcanefoam]

Digging deeper, if I look at the stack when the error happens, I am getting this:

java.lang.NoSuchMethodError: 'org.eclipse.jetty.io.RetainableByteBuffer org.eclipse.jetty.io.ByteBufferPool.acquire(int, boolean)'

So it seems it has to do with jetty. Hoever, looking at the source coude, the ArrayByteBufferPool (the actual buffer pool used) does have that method implemented., so I am not sure why it is failing.

[arcanefoam]

On a side note, when I install the workflow example in a clean Eclipse 2024-09, I am getting the same exception.

[rhollom]

This would point to a version mismatch with Jetty. Which version are you compiling against, and which version are you running with?

Pay close attention to the return type of acquire. Does ArrayByteBufferPool return RetainableByteBuffer.Mutable, RetainableByteBuffer, or ByteBuffer? Earlier versions of Jetty returned ByteBuffer (Jetty <12), even though the parameters (int, boolean) stayed the same. Version 12.0.x returned RetainableByteBuffer. Version 12.1.x returns RetainableByteBuffer.Mutable. My guess is that you are compiling against 12.1 and running with 12.0, or some other incompatible combination.

[arcanefoam]

@rhollom That did the trick, I had copied the Jetty version from the glsp repositories. For example, https://github.com/eclipse-glsp/glsp-server/blob/v2.4.0/targetplatforms/r2024-09.target uses version 12.0.12. So I was using that, but no matter what I tried, once installed via my update site it used 12.1.4.
Updating my target to use 12.1.4, solves the issue.

Maybe I need a tutorial on how to make my features enforce the versions I want :/.

[tortmayr]

@rhollom Thanks for catching that. The versioning issue is something that we also should fix in GLSP directly.
I will create an issue for that.