pthread_barrier_t 사용법 (pthread barrier)

// VERY VERY SIMPLE EXAMPLE BELOW !!

#include <pthread.h>

#include <stdlib.h>

#include <unistd.h>

#include <stdio.h>

#define RANGE_WORK_NUM  (5)

#define RANGE_SLEEP     (100000)

#define NUM_THREADS     (4)

typedef struct {

    unsigned int id;

    pthread_barrier_t *bar;

} worker_param_t;

static void* worker(void *carpark_in) {

    worker_param_t *worker_param = (worker_param_t *)carpark_in;

    unsigned int seed, heart_beat = 0;

    unsigned int i = 0;

    printf("[%02u]+worker\r\n", worker_param->id);

    for (;i < rand_r(&seed) % RANGE_WORK_NUM; i++) {

        usleep(rand_r(&seed) % RANGE_SLEEP);

        printf("[%02u] do work... = %u\r\n", worker_param->id, heart_beat++);

    }

    

    pthread_barrier_wait(worker_param->bar);

    printf("[%02u]-worker\r\n", worker_param->id);

    return (NULL);

}

int main(int argc, char *argv[]) {

    unsigned int i;

    worker_param_t worker_param[NUM_THREADS];

    pthread_t workers[NUM_THREADS];

    pthread_barrier_t bar;

    pthread_barrier_init(&bar, NULL, NUM_THREADS);

    

    for (i = 0; i < NUM_THREADS; i++) {

        worker_param[i].id = i;

        worker_param[i].bar = &bar;

        pthread_create(&workers[i], NULL, worker, (void *)&worker_param[i]);

    }

    printf("start join\r\n");

    for (i = 0; i < NUM_THREADS; i++) {

        pthread_join(workers[i], NULL);

    }

    printf("---\r\n");

    

    /*Changed from resturn(0) */

    return (EXIT_SUCCESS);

}