C語言多線程

#include <stdio.h>
#include <pthread.h>

#define NUM 10

void thread(void * arg)
{
int i;
for (i=0;i<1;i++) {
printf ("in thread:%d\n", (int)arg);
sleep (1);
}
}

int main(void)
{
pthread_t id[NUM];
int i,ret;

for (i=0;i<NUM;i++) {
    ret = pthread_create(&id[i], NULL, (void *)thread, (void *)i);
    if (ret) {
        printf("create pthread error\n");
        return 1;
    }
}

for (i=0;i<NUM;i++) {
    pthread_detach(id[i]);
}

while (1);

return 0;

}