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Re: PSA: Clock drift and pkgin



On 2023-12-24 09:26, Michael van Elst wrote:
simonb%NetBSD.org@localhost (Simon Burge) writes:

qemu uses ppoll() which is implemented with pollts() to do emulated
timers, so that doesn't help here.  I don't know what simh uses, nor
any of the other emulators.

simh uses pthread_cond_timedwait().

This actually waits using TIMER_ABSTIME for a deadline, but which is
converted to a timeout with ts2timo() and passed to sleepq_block()
as a number of ticks to wait for.

Oh? So we are actually not POSIX compliant on that one? Interesting.
(POSIX explicitly says that the timeout should be for an absolute time, which means that if you for example update the clock, moving it backwards, the timeout should still only happen when that time arrives, and not after some precomputed number of ticks.)

  Johnny

--
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt%softjar.se@localhost             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol


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