mirror of
https://github.com/fluencelabs/musl
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32 lines
830 B
C
32 lines
830 B
C
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#include "pthread_impl.h"
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int pthread_barrier_wait(pthread_barrier_t *b)
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{
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int cur;
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/* Trivial case: count was set at 1 */
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if (!b->__limit) return PTHREAD_BARRIER_SERIAL_THREAD;
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/* Wait for anyone still suspended at previous use of barrier */
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while ((cur=b->__left))
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__wait(&b->__left, &b->__waiters, cur, 0);
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/* If we are the last to reach barrier, reset it and wake others */
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if (a_fetch_add(&b->__count, 1) == b->__limit) {
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b->__left = b->__limit;
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b->__count = 0;
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__wake(&b->__count, -1, 0);
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return PTHREAD_BARRIER_SERIAL_THREAD;
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}
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/* Wait for our peers to reach the barrier */
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while ((cur=b->__count))
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__wait(&b->__count, 0, cur, 0);
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/* If we're the last to wake up and barrier is awaiting reuse */
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if (a_fetch_add(&b->__left, -1) == 1 && b->__waiters)
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__wake(&b->__left, -1, 0);
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return 0;
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}
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