Remove job object and startup suspended behavior

[miniksa]

Summary of the Pull Request

Removes the ConhostConnection work that set up a job object and created everything suspended. I don't believe this is or should be necessary as the ConPTY'd conhost should realize that the server end of the connection is gone and gracefully shut down (and tell its clients to shut down).

PR Checklist

• Closes Find the actual issue keeping conhosts from exiting when tabs are closed #2185
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Detailed Description of the Pull Request / Additional comments

I believe that using a job here is just covering up an underlying problem with outstanding handles, bad eventing, or other message communication failures. The job is a big hammer solution to just terminate everything when the terminal goes down, which I believe is responsible for some of the pwsh.exe post-mortem debugger sessions I'm seeing (as the conhost goes down and then pwsh throws an unhandled exception).

Overall, if there's an issue in this area, I think we can debug and diagnose it individually and fix the leftover handle, untriggered/unhandled event, etc. So I'm taking out the job object and we'll see how things go.

Also, I believe some of the issues that this was covering up have been resolved in other ways between when it was installed and now. I did some playing around and didn't get any orphaned conhost.exes (or their clients). So this must be already better than it used to be.

Validation Steps Performed

Launched Terminal, closed it normally.
Launched Terminal, killed it in process explorer.
Launched Terminal with many tabs of varying types (pwsh, powershell, cmd) and killed Terminal in process explorer.

In all cases, the conhosts and their children were cleaned up appropriately without the job object.

[DHowett-MSFT]

Potential 0.3 QOL fix?

[zadjii-msft]

Does this actually close #2185, or does it just open the door to investigating it?

I'd also make sure that closing a non-final wsl tab doesn't cause the terminal to crash, because that was something mentioned in #1445 which seems similar

[zadjii-msft]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[miniksa]

Does this actually close #2185, or does it just open the door to investigating it?

I'd also make sure that closing a non-final wsl tab doesn't cause the terminal to crash, because that was something mentioned in #1445 which seems similar

Opens the door to investigate it more. I'll make sure it gets reactivated when merging this closes it.

And I'll keep working on testing scenarios around the exit.

[ghost]

🎉Windows Terminal Preview v0.4.2382.0 has been released which incorporates this pull request.:tada:

Handy links:

• Release Notes
• Store Download