typedef struct dList{
  struct dList *flink;  
  struct dList *blink;  
  int val;
}* dListe;


dListe li;
pthread_mutex_t mut;


void *consume(void *p){
  
  int ret;
  dListe temp;

  while(any){
    ret=pthread_mutex_lock(&mut);

    if(li!=NULL){
      temp=li->flink;
      free(li);
      li=temp;
      if(li!=NULL)
	li->blink=NULL;
    }

    ret=pthread_mutex_unlock(&mut);
  }
  
}

void *produce(void *p){
  
  int ret;
  dListe temp;
  
  while(any){
    ret=pthread_mutex_lock(&mut);


    temp=malloc(sizeof(struct dList));
    temp->flink=li;
    temp->blink=NULL;
    temp->val=1;
    if(li!=NULL)
      li->blink=temp;
    li=temp;

    ret=pthread_mutex_unlock(&mut);
  }
}


int main(){

  pthread_t th1;
  pthread_t th2;

  int ret;

  ret=pthread_mutex_init(&mut,NULL);
 
  ret=pthread_create(&th2,NULL,produce,NULL);
  ret=pthread_create(&th1,NULL,consume,NULL);

  ret=pthread_join(th1,NULL);
  ret=pthread_join(th2,NULL);
 
}