Fix OAuth local server shutdown deadlock and add timeout#66
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The local OAuth server uses unbuffered channels for communicating results between HTTP handlers and the main goroutine. If the 5-minute user timeout fires and a handler tries to write to the channel after nobody is reading, a deadlock occurs: Shutdown() waits for the handler, the handler waits for a channel reader. Drain both channels before calling Shutdown() to break the deadlock, and add a 10-second timeout to Shutdown() as a safety net.
andresbott
approved these changes
Feb 26, 2026
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Summary
Fix deadlock on shutdown. The local OAuth server uses unbuffered channels (
ims-go/login/server.go:91-92) to send results from HTTP handlers to the main goroutine. If the 5-minute user timeout fires and a late browser callback writes to the channel with nobody reading, a circular dependency forms:Shutdown()waits for the handler to return, the handler blocks on the channel write. Draining both channels beforeShutdown()breaks the deadlock.Add 10-second timeout to
Shutdown(). The original code usedcontext.Background()with no deadline, which could wait indefinitely. Now usescontext.WithTimeoutas a safety net.Add documentation.
docs/oauth-shutdown-deadlock.mdexplains the deadlock scenario step-by-step with file and line references.