gh-153005: Use a monotonic clock for concurrent.interpreters Queue timeouts#154156
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fedonman wants to merge 1 commit into
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gh-153005: Use a monotonic clock for concurrent.interpreters Queue timeouts#154156fedonman wants to merge 1 commit into
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…eue timeouts Queue.get() and Queue.put() computed their timeout deadline from time.time(), the wall clock. If the system clock was stepped (NTP, a manual change) while a call was blocked, the timeout could over- or under-wait. queue.Queue uses time.monotonic() for the same reason. Compute the deadline and check it against time.monotonic() instead.
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concurrent.interpreters.Queue.get()andQueue.put()computed their timeout deadline fromtime.time(), the wall clock:If the system clock is stepped (an NTP correction, a manual change) while a call is blocked, the deadline is off by the size of the adjustment, so the call can over- or under-wait.
queue.Queue, which this queue is meant to be compatible with, usestime.monotonic()precisely to avoid that.This computes the deadline and checks it against
time.monotonic()instead, in bothget()andput().The issue also mentions that
int(timeout)truncates a float timeout. That part was left out here on purpose: in the earlier PR #153006 a core reviewer asked to keep the clock change separate and to discuss theint()conversion (and the matching docs and other stdlib queues) first. This PR is only the monotonic-clock fix.