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LibPthread: Use realtime clock for futex_wait()

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If we get an absolute time passed to one of the pthread_*wait methods,
this is not an absolute monotonic time but rather an absolute wall
time. This means that we also need to pass FUTEX_CLOCK_REALTIME to the
futex syscall to ensure we're not using the monotonic clock.
This commit is contained in:
Jelle Raaijmakers 2021-04-26 17:22:25 +02:00 • committed by Andreas Kling
parent b630e39fbb
commit d1f33ec795
1 changed files with 1 additions and 1 deletions
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2
Userland/Libraries/LibPthread/pthread.cpp
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@ -442,7 +442,7 @@ static int futex_wait(uint32_t& futex_addr, uint32_t value, const struct timespe
{ {
int saved_errno = errno; int saved_errno = errno;
// NOTE: FUTEX_WAIT takes a relative timeout, so use FUTEX_WAIT_BITSET instead! // NOTE: FUTEX_WAIT takes a relative timeout, so use FUTEX_WAIT_BITSET instead!
int rc = futex(&futex_addr, FUTEX_WAIT_BITSET, value, abstime, nullptr, FUTEX_BITSET_MATCH_ANY); int rc = futex(&futex_addr, FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME, value, abstime, nullptr, FUTEX_BITSET_MATCH_ANY);
if (rc < 0 && errno == EAGAIN) { if (rc < 0 && errno == EAGAIN) {
// If we didn't wait, that's not an error // If we didn't wait, that's not an error
errno = saved_errno; errno = saved_errno;