fix(after): don't retain the caller's async context for tasks that never settle - #98568
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fix(after): don't retain the caller's async context for tasks that never settle#98568mircoservices wants to merge 1 commit into
mircoservices wants to merge 1 commit into
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…ver settle `AwaiterMulti.waitUntil` registers its bookkeeping `.then()` inside the caller's async context. A `.then()` holds the context that was current when it was registered for as long as the promise stays unsettled, so a task that never settles pins the context of the request that registered it. On a self-hosted server that is unbounded: `createInternalWaitUntil` builds one `AwaiterOnce` per server and only drains it on `onServerClose`, so nothing releases the entry while the process runs. For a render the retained context holds the RSC flight payload. Register the reaction through `createSnapshot()` instead, which restores an empty context. The promise is still tracked and still awaited, so `after()` semantics are unchanged; only the retained graph shrinks. Measured on 16.4.0-canary.26 with a route calling `after()` on a never-settling promise, 300 requests each holding 1 MiB in request-scoped context: 300.0 MiB retained before, 0.0 MiB after. Claude-Session: https://claude.ai/code/session_014QS6jWEQXPeLzx5L9jELTf
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fixes #98561
AwaiterMulti.waitUntilregisters a bookkeeping.then()in the caller’s async context. If the promise never settles, that context stays in memory. On self-hosted servers, the shared awaiter only drains when the server closes, so retained request data keeps growing.The fix uses
createSnapshot()to register the bookkeeping callback in an empty context. Tasks are still tracked and awaited.All nine unit tests pass with the fix. Reverting the fix causes the two never-settling tests to fail.