[🐛 Bug]: "System.IO.IOException : Cannot access a closed stream" when disposing DevToolsSession about selenium HOT 5 OPEN

@arnonax-tr, thank you for creating this issue. We will troubleshoot it as soon as we can.

from selenium.

This issue is obvious.

network.RequestPaused += async (_, args) =>
{
  await network.ContinueRequestWithoutModification(args.RequestData);
}

which may lead to System.IO.IOException : Cannot access a closed stream.

It happens because your async event handler is invoked in background, while main execution program is continuing. And there is a chance that main execution flow disposes driver earlier than your network.ContinueRequestWithoutModification(args.RequestData).

This situation is fixed in new BiDi approach (#14318). I have no ideas how to fix it.

Probably making your event handler sync can help (at least please try):

network.RequestPaused += (_, args) =>
{
  Task.Run(async () => await network.ContinueRequestWithoutModification(args.RequestData));
}

EDITED:
You may prove my theory via adding a delay in your async handler like await Task.Delay(5_000) before invocation of network.Continue....

from selenium.

And there is a chance that main execution flow disposes driver earlier than your network.ContinueRequestWithoutModification(args.RequestData).

I don't think so. That's exactly the reason I added the CountdownEvent object (executingHandlers). This should ensure that I'm not disposing the driver (or even the DevToolsSession) before all event handlers are done. (Or if they just start after dispose has already started, they immediately exit due to the if (!executingHandlers.TryAddCount()) statement)

from selenium.

Regarding the BiDi approach: do you have an ETA for when it will be available? Also I'll be grateful if you can provide an example of how my code should look like with that approach.

from selenium.

That's exactly the reason I added the CountdownEvent object (executingHandlers)

Your event handler is async void, selenium invokes (actually schedules your delegate in TaskScheduler to be invoked), and we don't know when exactly your handler is actually invoked. Moreover, in selenium we really fire and forget event handlers. This is design issue, which may lead to unexpected behavior in race conditions. This design issue is addressed in BiDi implementation (or at least should be addressed).

No ETA, PR is under review.

from selenium.