Add FileHandle.read(until:) to avoid blocking on slow exit test events.#1782
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…nts. If an exit test runs for a long time, we necessarily block until it terminates before the calling task resumes. We also wait until the end of the exit test to consume any events from its event stream (by calling `FileHandle.readToEnd()` and thus waiting for the write end of the pipe to close). This PR breaks up reading from the exit test's event stream so that we read one line at a time, then yield before processing the event. The result is that we process events sooner after they occur and we allow other tasks to use the thread we're camped on at least for a little bit of time.
grynspan
requested review from
briancroom,
jerryjrchen and
stmontgomery
as code owners
grynspan
added
exit-tests
stmontgomery
approved these changes
Jul 10, 2026
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If an exit test runs for a long time, we necessarily block until it terminates before the calling task resumes. We also wait until the end of the exit test to consume any events from its event stream (by calling
FileHandle.readToEnd()and thus waiting for the write end of the pipe to close).This PR breaks up reading from the exit test's event stream so that we read one line at a time, then yield before processing the event. The result is that we process events sooner after they occur and we allow other tasks to use the thread we're camped on at least for a little bit of time.
I'll also be able to use
read(until:)in the harness.Checklist: