Linux 多线程按照线程顺序打印字符

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

 int num = ;
 pthread_mutex_t mutex_lock = PTHREAD_MUTEX_INITIALIZER;
 pthread_cond_t cond_ready = PTHREAD_COND_INITIALIZER;

 void *output_chara(void *arg)
 {
     int i;
     int cond_num = (int) arg;

     for (i = ; i < ; i++){
         pthread_mutex_lock(&mutex_lock);
         while (num != cond_num){
             pthread_cond_wait(&cond_ready, &mutex_lock);
         }

         printf("%c", 'A' + cond_num);

         num = (num + ) % ;

         pthread_mutex_unlock(&mutex_lock);
         pthread_cond_broadcast(&cond_ready);
     }
 }

 int main()
 {
     int i;
     pthread_t tid[];

     for (i = ; i < ; i++){
         pthread_create(&tid[i], NULL, output_chara, (void *)i);
     }

     for (i = ; i < ; i++){
         pthread_join(tid[i], NULL);
     }

     return ;
 }

output:

ABCABCABCABCABCABCABCABCABCABC