fix SAL non-determinism #1562
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fix SAL non-determinism #1562
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Motivation: The SAL tests suffered from a rare non-determinism: When we go onto the EventLoop to get a value and then leave it, we previously just assumed that the EventLoop would park itself before we did any futher operations on it. That was mostly true because the tests are doing one thing after the other. There was however a narrow race: If the tests enqueued new work onto the EventLoop before the EventLoop parked itself, then the new work would be run _before_ the EL parks itself. That would make the _next_ operation fail because the operations usually start by checking that we're parked because that's a synchronisation point between tests and EL. Modifications: Actually wait until the EL's parked. That proves we found our synchronisation point. Result: - fixes apple#1514 - fixes apple#1545 - fixes apple#1548 - fixes apple#1550
glbrntt
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Jun 18, 2020
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Motivation:
The SAL tests suffered from a rare non-determinism: When we go onto the
EventLoop to get a value and then leave it, we previously just assumed
that the EventLoop would park itself before we did any futher operations
on it.
That was mostly true because the tests are doing one thing after the
other. There was however a narrow race: If the tests enqueued new work
onto the EventLoop before the EventLoop parked itself, then the new work
would be run before the EL parks itself.
That would make the next operation fail because the operations usually
start by checking that we're parked because that's a synchronisation
point between tests and EL.
Modifications:
Actually wait until the EL's parked. That proves we found our
synchronisation point.
Result: