Custom-Thread-Barrier-Implementation/ThreadBarrier.c

#include "ThreadBarrier.h"
#include <stdio.h>

void
thread_barrier_print(th_barrier_t* th_barrier) {

	printf("th_barrier->threshold_count = %u\n", th_barrier->threshold_count);
	printf("th_barrier->curr_wait_count = %u\n", th_barrier->curr_wait_count);
	printf("th_barrier->is_ready_again = %s\n", th_barrier->is_ready_again ? "true" : "false");
}


void
thread_barrier_init(th_barrier_t* barrier,
	uint32_t threshold_count) {

	barrier->threshold_count = threshold_count;
	barrier->curr_wait_count = 0;

	pthread_mutex_init(&(barrier->mutex), NULL);

	pthread_cond_init(&(barrier->cv), NULL);
	pthread_cond_init(&(barrier->busy_cv), NULL);

	barrier->is_ready_again = true;
}

void
thread_barrier_wait(th_barrier_t* barrier) {

	pthread_mutex_lock(&(barrier->mutex));

	while (barrier->is_ready_again == false) {
		pthread_cond_wait(&(barrier->busy_cv), &(barrier->mutex));
	}

	if (barrier->curr_wait_count + 1 == barrier->threshold_count) {

		barrier->is_ready_again = false;
		pthread_cond_signal(&(barrier->cv));
		pthread_mutex_unlock(&(barrier->mutex));
		return;

	}

	barrier->curr_wait_count++;
	pthread_cond_wait(&barrier->cv, &barrier->mutex);
	barrier->curr_wait_count--;

	if (barrier->curr_wait_count == 0) {
		barrier->is_ready_again = true;
		pthread_cond_broadcast(&(barrier->busy_cv));
	}
	else {
		pthread_cond_signal(&(barrier->cv));
	}


	pthread_mutex_unlock(&(barrier->mutex));
}

void
thread_barrier_destroy(th_barrier_t* barrier) {

	pthread_cond_destroy(&(barrier->cv));
	pthread_cond_destroy(&(barrier->busy_cv));
	pthread_mutex_destroy(&(barrier->mutex));
}