基于单链表的生产者消费者模型

我们用两个线程分别表示生产者与消费者，用单链表表示缓冲区。
生产者生产数据，插入到单链表的头部。
消费者消费数据，从单链表的头部读数据。

#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
typedef struct palce_t
{
	struct palce_t *next;
	int data;
}place;
place *head=NULL;
static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t need_product = PTHREAD_COND_INITIALIZER;
void palce_init(place *p)
{
	if(p!=NULL){
		p->next=NULL;
		p->data=0;
	}
}
void *consumer(void * val)
{
	place *p=NULL;
	while(1){
		pthread_mutex_lock(&lock);
		while(head==NULL){
			pthread_cond_wait(&need_product,&lock);
		}
		p=head;
		head=head->next;
		p->next=NULL;

		pthread_mutex_unlock(&lock);
		printf("consumer !data=%d\n",p->data);
		free(p);
		sleep(1);

	}

}
void* Product(void* _val)
{
	while(1){
		sleep(1);
		place *p=malloc(sizeof(place));
		pthread_mutex_lock(&lock);
		palce_init(p);
		p->next=head;
		p->data=rand()%1000;
		head=p;
		pthread_mutex_unlock(&lock);
		printf("Call consumer!data=%d\n",p->data);
		pthread_cond_signal(&need_product);
	}

}
int main ()
{
	pthread_t t1;
	pthread_t t2;

	pthread_create(&t1,NULL,consumer,NULL);
	pthread_create(&t2,NULL,Product,NULL);

	pthread_join(t1,NULL);
	pthread_join(t2,NULL);
	return 0;
}