Condition Variables as Events

#include <stdio.h>
#include <stdlib.h>
  
typedef struct
{
    pthread_mutex_t mx;
    pthread_cond_t cv;
    int flag;
}event;
  
void wait_for_event(event *ev)
{
    pthread_mutex_lock(&ev->mx);
    while(flag==0)
    {
        pthread_cond_wait(&ev->cv,&ev->mx);
    }
    ev->flag = 0;
    pthread_mutex_unlock(&ev->mx);
}
  
void send_event(event *ev)
{
    pthread_mutex_lock(&ev->mx);
    ev->flag=1;
    pthread_cond_signal(&ev->cv);
    //pthread_cond_broadcast(&ev->cv);
    pthread_mutex_unlock(&ev->mx);
}
  
void init_event(event *ev)
{
    ev->flag = 0;
    pthread_mutex_init(&ev->mx,NULL);
}
  
void *thr1(void *p)
{
    event *e1 = (event *)p;
  
    //
    //
    wait_for_event(&e1);
    //
}
  
void *thr2(void *p)
{
    event *e1 = (event *)p;
  
    //
    send_event(&e1);
    //
}
  
int main(void) {
    event e1;
    pthread_t t1,t2;
    init_event(&e1);
  
    pthread_create(&t1,NULL,thr1,&e1);
    pthread_create(&t2,NULL,thr2,&e1);
  
    return EXIT_SUCCESS;
}