#include	"unpthread.h"#define	Pthread_mutex_lock(mptr) \	{	int  n; \		if ( (n = pthread_mutex_lock(mptr)) != 0) \			{ errno = n; err_sys("pthread_mutex_lock error"); } \	}#define	Pthread_mutex_unlock(mptr) \	{	int  n; \		if ( (n = pthread_mutex_unlock(mptr)) != 0) \			{ errno = n; err_sys("pthread_mutex_unlock error"); } \	}#define	Pthread_cond_wait(cptr,mptr) \	{	int  n; \		if ( (n = pthread_cond_wait(cptr,mptr)) != 0) \			{ errno = n; err_sys("pthread_cond_wait error"); } \	}#define	Pthread_cond_signal(cptr) \	{	int  n; \		if ( (n = pthread_cond_signal(cptr)) != 0) \			{ errno = n; err_sys("pthread_cond_signal error"); } \	}#define	NLOOP	   	 50#define	BUFFSIZE	 10struct buf_t {  int		b_buf[BUFFSIZE];	/* the buffer which contains integer items */  int		b_nitems;			/* #items currently in buffer */  int		b_nextget;  int		b_nextput;  pthread_mutex_t	b_mutex;  pthread_cond_t	b_cond_consumer;	/* consumer waiting to get */  pthread_cond_t	b_cond_producer;	/* producer waiting to put */} buf_t;void	*produce_loop(void *);void	*consume_loop(void *);intmain(int argc, char **argv){	int			n;	pthread_t	tidA, tidB;	printf("main, addr(stack) = %x, addr(global) = %x, addr(func) = %x\n",			&n, &buf_t, &produce_loop);	if ( (n = pthread_create(&tidA, NULL, &produce_loop, NULL)) != 0)		errno = n, err_sys("pthread_create error for A");	if ( (n = pthread_create(&tidB, NULL, &consume_loop, NULL)) != 0)		errno = n, err_sys("pthread_create error for B");		/* wait for both threads to terminate */	if ( (n = pthread_join(tidA, NULL)) != 0)		errno = n, err_sys("pthread_join error for A");	if ( (n = pthread_join(tidB, NULL)) != 0)		errno = n, err_sys("pthread_join error for B");	exit(0);}voidproduce(struct buf_t *bptr, int val){	Pthread_mutex_lock(&bptr->b_mutex);		/* Wait if buffer is full */	while (bptr->b_nitems >= BUFFSIZE)		Pthread_cond_wait(&bptr->b_cond_producer, &bptr->b_mutex);		/* There is room, store the new value */	printf("produce %d\n", val);	bptr->b_buf[bptr->b_nextput] = val;	if (++bptr->b_nextput >= BUFFSIZE)		bptr->b_nextput = 0;	bptr->b_nitems++;		/* Signal consumer */	Pthread_cond_signal(&bptr->b_cond_consumer);	Pthread_mutex_unlock(&bptr->b_mutex);}intconsume(struct buf_t *bptr){	int		val;	Pthread_mutex_lock(&bptr->b_mutex);		/* Wait if buffer is empty */	while (bptr->b_nitems <= 0)		Pthread_cond_wait(&bptr->b_cond_consumer, &bptr->b_mutex);		/* There is data, fetch the value */	val = bptr->b_buf[bptr->b_nextget];	printf("consume %d\n", val);	if (++bptr->b_nextget >= BUFFSIZE)		bptr->b_nextget = 0;	bptr->b_nitems--;		/* Signal producer; it might be waiting for space to store */	Pthread_cond_signal(&bptr->b_cond_producer);	Pthread_mutex_unlock(&bptr->b_mutex);	return(val);}void *produce_loop(void *vptr){	int		i;	printf("produce_loop thread, addr(stack) = %x\n", &i);	for (i = 0; i < NLOOP; i++) {		produce(&buf_t, i);	}	return(NULL);}void *consume_loop(void *vptr){	int		i, val;	printf("consume_loop thread, addr(stack) = %x\n", &i);	for (i = 0; i < NLOOP; i++) {		val = consume(&buf_t);	}	return(NULL);}