Rich Felker
6016457011
this implementation is rather heavy-weight, but it's the first solution i've found that's actually correct. all waiters actually wait twice at the barrier so that they can synchronize exit, and they hold a "vm lock" that prevents changes to virtual memory mappings (and blocks pthread_barrier_destroy) until all waiters are finished inspecting the barrier. thus, it is safe for any thread to destroy and/or unmap the barrier's memory as soon as pthread_barrier_wait returns, without further synchronization.
8 lines
145 B
C
8 lines
145 B
C
#include "pthread_impl.h"
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int pthread_barrierattr_setpshared(pthread_barrierattr_t *a, int pshared)
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{
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*a = pshared ? INT_MIN : 0;
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return 0;
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}
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