linux多线程初学议论

linux多线程初学讨论
初学linux多线程，基本函数的意思也都理解，想做个程序实现个几个线程同时往一个缓冲区里放数据，几个线程取数据，程序放上来，希望能抛砖引玉，忘高手们给挑挑毛病，讲讲逻辑过程最好，看我理解的是否正确！谢谢！

#include<stdio.h>
#include<pthread.h>
#define SIZE 4
struct product
{
  pthread_mutex_t mutex;
  pthread_cond_t notfull;
  pthread_cond_t notempty;
  int pos;
  int buf[SIZE];
};

void init(struct product *t)
{
  pthread_mutex_init(&t->mutex,NULL);
  pthread_cond_init(&t->notfull,NULL);
  pthread_cond_init(&t->notempty,NULL);
  t->pos =-1;
}

void put(struct product *t,int data)
{
  pthread_mutex_lock(&t->mutex);
  if((t->pos+1)>(SIZE-1))
  pthread_cond_wait(&t->notfull,&t->mutex);
  t->pos = t->pos +1;
  t->buf[t->pos] = data;
  printf("Thread %d put a data:%d to pos%d\n",pthread_self(),data,t->pos);
 pthread_cond_broadcast(&t->notempty);
  pthread_mutex_unlock(&t->mutex);
}

void get(struct product *t)
{
  int rtntemp;
  pthread_mutex_lock(&t->mutex);
  if(t->pos<0)
  pthread_cond_wait(&t->notempty,&t->mutex);
  printf("Thread %d get a data:%d from pos%d\n",pthread_self(),t->buf[t->pos],t->pos);
  rtntemp = t->buf[t->pos];
  t->pos = t->pos -1;
  pthread_cond_broadcast(&t->notfull);
  pthread_mutex_unlock(&t->mutex);
}

struct product pdt;
void *putter()
{
  int n;
  for(n=0;n<8;n++)
  put(&pdt,n);
}

void *getter()
{ 
int n;
  for(n=0;n<8;n++)
  get(&pdt);
}


int main(void)
{
  pthread_t pt1,pt2,gt1,gt2;
  void *retval;
  init(&pdt);
  pthread_create(&pt1,NULL,putter,0);
  pthread_create(&pt2,NULL,putter,0);
  pthread_create(&gt1,NULL,getter,0);
  pthread_create(&gt2,NULL,getter,0);

  pthread_join(pt1,&retval);
  pthread_join(pt2,&retval);
  pthread_join(gt1,&retval);
  pthread_join(gt2,&retval);
  return 0;
}



[解决办法]
太基础了，还是回去闷头学吧。