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

static pthread_mutex_t cs_mutex;

typedef struct {
  int c;
  int *red;
} st;

void* print(void *pParam) {
    int c = ((st*)pParam)->c;
    int *red = ((st*)pParam)->red;
    int i;

    for(i = 0; i < 1000; i++) {
      int b = 0;
      while (!b) {
          pthread_mutex_lock(&cs_mutex);
          b = (*red == c);
          pthread_mutex_unlock(&cs_mutex);
      };
      pthread_mutex_lock(&cs_mutex);
      printf("%d", c + 1);
      fflush(stdout);
      *red = (*red + 1) % 3;
      pthread_mutex_unlock(&cs_mutex);
    }

    return 0;
}

int main(void) {
    pthread_t hPrint1;
    pthread_t hPrint2;
    pthread_t hPrint3;

    pthread_mutex_init(&cs_mutex, NULL);

    st str[3];

    int red = 0;

    int i;
    for (i = 0; i < 3; i++) {
      str[i].c = i;
      str[i].red = &red;
    }

    pthread_create(&hPrint1, NULL, print, (void*)&str[0]);
    pthread_create(&hPrint2, NULL, print, (void*)&str[1]);
    pthread_create(&hPrint3, NULL, print, (void*)&str[2]);

    getchar();

    return 0;
}