43 lines
1.3 KiB
C
43 lines
1.3 KiB
C
/*
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* barrier.h
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*
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* This header file describes the "barrier" synchronization
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* construct. The type barrier_t describes the full state of the
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* barrier including the POSIX 1003.1c synchronization objects
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* necessary.
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*
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* A barrier causes threads to wait until a set of threads has
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* all "reached" the barrier. The number of threads required is
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* set when the barrier is initialized, and cannot be changed
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* except by reinitializing.
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*/
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#include <pthread.h>
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/*
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* Structure describing a barrier.
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*/
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typedef struct barrier_tag {
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pthread_mutex_t mutex; /* Control access to barrier */
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pthread_cond_t cv; /* wait for barrier */
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int valid; /* set when valid */
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int threshold; /* number of threads required */
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int counter; /* current number of threads */
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int cycle; /* alternate wait cycles (0 or 1) */
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} barrier_t;
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#define BARRIER_VALID 0xdbcafe
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/*
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* Support static initialization of barriers
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*/
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#define BARRIER_INITIALIZER(cnt) \
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{PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, \
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BARRIER_VALID, cnt, cnt, 0}
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/*
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* Define barrier functions
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*/
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extern int barrier_init (barrier_t *barrier, int count);
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extern int barrier_destroy (barrier_t *barrier);
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extern int barrier_wait (barrier_t *barrier);
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