fix(stdio): cancel supervisor job on close to prevent process hang after EOF#735
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…ayloadResult The content-based polymorphic deserializer matches GetTaskResult on the presence of "taskId" alone. This incorrectly captures GetTaskPayloadResult responses (tasks/result), which wrap arbitrary JSON and may also contain a "taskId" key but not a "status" key. Tighten the discriminator to require both "taskId" and "status", since GetTaskResult always has both fields. GetTaskPayloadResult responses (which lack "status") now correctly fall through to other deserializers or the empty result handler. Fixes modelcontextprotocol#601 Signed-off-by: Dayna Blackwell <dayna@blackwell-systems.com>
…ter EOF When stdin reaches EOF, StdioServerTransport.close() cleans up all child jobs and invokes the onClose callback. However, the supervisor job backing the coroutine scope was never cancelled, keeping the scope alive indefinitely. This caused the server process to hang after the client disconnected. Cancel the supervisor job at the end of close() so the coroutine scope completes and the process can exit. Fixes modelcontextprotocol#708 Signed-off-by: Dayna Blackwell <dayna@blackwell-systems.com>
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Motivation and Context
Fixes #708
When a client closes stdin (e.g., Docker container shutdown, opencode disconnect),
StdioServerTransport.close()cleans up all child jobs (reading, processing, sending), flushes and closes I/O streams, and invokes theonClosecallback chain. However, theSupervisorJobbacking the coroutine scope was never cancelled, keeping the scope alive indefinitely. The server process hangs even though all meaningful work has completed.Fix
Extract the
SupervisorJobinto a named field and cancel it at the end ofclose(), after all cleanup is done. This allows the coroutine scope to complete and the process to exit.How Has This Been Tested?
StdioServerTransportTestpasses (all tests green)supervisorJob.cancel()) at the end of the already-testedclose()methodexitProcess(0)) would no longer be necessaryTypes of changes
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