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Code RoomGoroutine leak on context cancellation
HardPrep Room Coding #4000

Goroutine leak on context cancellation

Vibe & agenticConcurrencySenior–Staff~20 min

You asked an AI assistant for a Go function that fans out HTTP health checks concurrently and returns the first success, cancelling the rest. It produced:

It returns a healthy URL in your test. What goes wrong at scale?

Implement
parked_goroutine_count(worker_outcomes: list[str], channel_buffer: int) → int
Examples
in[["healthy","healthy","healthy"],0]out2
in[["healthy","healthy","healthy"],3]out0
in[["unhealthy","error","unhealthy"],0]out0
What a strong answer looks like

Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it (tests, edge cases, reading critically), and how you’d re-prompt or decompose to get it right.

0:00 of about 20 min

Vibe & agentic: describe the solution in plain language (or narrate it) and the coach grades your approach.

Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.