runtime: stop single goroutine

[dlsniper]

During debugging it would be useful to resume all goroutines except a single one, as it's the case in other programming languages.

In #25578 we have the request to resume a single goroutine while all others are stopped so this would be the similar/opposite request.

I'm sorry I don't know what else I could put in this request to make it more useful. Feel free to edit it with more details. Thank you.

[andybons]

@aclements

[pellared]

I would say that we probably need support for pausing and resuming the execution of a given goroutine.
More context: go-delve/delve#2262

[aclements]

What's the use case for stopping a single goroutine? I can definitely see the value of resuming a single goroutine (#25578), but stopping a single goroutine is less clear to me. It may be that a single solution handles both cases, but I wanted to make sure I understand.

[pellared]

What's the use case for stopping a single goroutine? I can definitely see the value of resuming a single goroutine (#25578), but stopping a single goroutine is less clear to me. It may be that a single solution handles both cases, but I wanted to make sure I understand.

It helps "reproduce" possible improper synchronization (race conditions) in concurrent code during debugging.

Like freezing and thawing threads in the debugger in ecosystems supporting threads.

Reference go-delve/delve#2262