Application freezes due to using Edge

[HeikoKlare]

When using Edge as default browser for the IDE, the application sometimes freezes when Edge instances are created (e.g., for tooltips). I have experienced this sporadically. In my case, the application recovered after a pretty long waiting time (multiple minutes).

Same issue has now been reported in the official SWT repository: eclipse-platform/eclipse.platform.ui#2734

Currently, it has only been reported in combination with the monitor-specific scaling feature being enabled, but that may be because for the previous release of the IDE, Edge was only enabled by default when that feature was enabled. So there is a risk that applications using Edge are affected in general. We need to investigate what may causes these issues.

[amartya4256]

Is there a specific way to reproduce this? It dosn't seem to happen with me. What I have tried:

• Hovering over to create javadoc tooltips.
• Opening a javadoc tab.
• Starting the welcome page and starting a new shell with a browser in it.
• Starting multiple workspaces and trying to open the tooltip/welcome page on them simultaneously.

[HeikoKlare]

We are not aware of any specific way of reproducing this yet. So first task of the analysis is find a reproducer. What might help for this is eclipse-platform/eclipse.platform.swt#1706

[amartya4256]

I tried a few things to see if these things end up in freezing the main thread:

• Checking if infinite waiting for the lastFutureToExecute causes a freeze: No (The javadoc tooltip doesnt even show up - but no freezing)
• Checking if inifinite retries cause a freeze: No (The browser container / javadoc tooltip seems to be white/empty)
• Cant reproduce the effect locally using Browser tests: reduce timeout for instantiation to reasonable value eclipse-platform/eclipse.platform.swt#1706

I tried looking for a faulty place in the Edge instantiation where we could be blocking the main thread, but almost everyting is happening asynchronously. My assumptioon is that either it happens on instantiation or when we call setUrl or setText because hat's where we do wait for the webView to finish all its queued tasks. Would try messing around with it to see if it I can reproduce the behaviour.

Another question: Is the freeze only application wide, or the mouse also freezes preventing you from using the whole OS?