Slow console with word wrap

[frankbenoit]

Since 2023-06, and still with 2023-09 I experience a deadlock of the Eclipse IDE when I run a JUnit test on project level.

Steps to reproduces:

1. Have the console view with "word wrap" active
2. Have the Eclipse IDE started freshly with the console view not opened, e.g. as a view tab that is not the top most.
3. The project I run, does have ArchUnit tests that do create console output, even before the first test starts, in the class loading Right-click on the project, "Run as .." "JUnit test Alt-Shift X, T"

The status bar shows "Starting ...", the UI freezes and never comes back.

With "YourKit" I detected this potential dead lock, because this thread is locked for more than 10 seconds:

jdk.internal.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:252)
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:1672)
java.util.concurrent.LinkedBlockingQueue.offer(LinkedBlockingQueue.java:378)
org.eclipse.ui.internal.console.IOConsolePartitioner.offer(IOConsolePartitioner.java:712)
org.eclipse.ui.internal.console.IOConsolePartitioner.streamAppended(IOConsolePartitioner.java:695)
org.eclipse.ui.console.IOConsoleOutputStream.notifyParitioner(IOConsoleOutputStream.java:281)
org.eclipse.ui.console.IOConsoleOutputStream.encodedWrite(IOConsoleOutputStream.java:276)
org.eclipse.ui.console.IOConsoleOutputStream.write(IOConsoleOutputStream.java:260)
org.eclipse.debug.internal.ui.views.console.ProcessConsole$StreamListener.streamAppended(ProcessConsole.java:809)
org.eclipse.debug.internal.core.OutputStreamMonitor$1.run(OutputStreamMonitor.java:171)
org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:45)
org.eclipse.debug.internal.core.OutputStreamMonitor.fireStreamAppended(OutputStreamMonitor.java:168)
org.eclipse.debug.internal.core.OutputStreamMonitor.internalRead(OutputStreamMonitor.java:256)
org.eclipse.debug.internal.core.OutputStreamMonitor.read(OutputStreamMonitor.java:225)
org.eclipse.debug.internal.core.OutputStreamMonitor$$Lambda$1604.0x0000000801fef830.run()
java.lang.Thread.run(Thread.java:833)

Now, when I open the "Console" view first, I can avoid the deadlock.

[iloveeclipse]

Please if Eclipse hangs, run jstack and attach generated thread dump here.

[frankbenoit]

threads.txt

[iloveeclipse]

threads.txt

This doesn't show a deadlock. I guess the output is very specific, either too long lines or something SWT can't render fast enough.

[frankbenoit]

The console output of the completed test does have 22000 log lines. In the beginning there are 3 lines that are very long with 31724 characters each. Here ArchUnit lists the class-path with all found jar files.

[frankbenoit]

.. and "word wrap" button was pressed. (perhaps relevant)

[iloveeclipse]

.. and "word wrap" button was pressed. (perhaps relevant)

That is it. World wrap is not working well with lot of output.

[frankbenoit]

Hm, for me it is fine now, I know how to workaround now. Perhaps this issue can be closed. But a hard lesson for everyone coming into the same situation.

VS Code solves this by showing the first 1000 chars, then a tag "Show more (21KB)". When pressing it, it shows raw text only and switches off enhanced capabilities for performance reasons.

[frankbenoit]

So there is a potential logic bug ... When the console view is having word-wrap AND is initially not visible AND a first output with long lines is pushed, then it makes the IDE to freeze forever. If it is initially visible OR does not have word-wrap, it works well.

[jukzi]

word wrap is disabled by default and also the buffer is very limited by default. If you change that you need to live with it or propose a performance improvement patch