s1.c

s1.c是server

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <pthread.h>
#include <semaphore.h>
void *Client(void *arg);
void *thread_function(void *arg);


int count=0;
sem_t mutex;
pthread_t a_thread;   
        int server_sockfd, client_sockfd;
        int server_len, client_len;
        struct sockaddr_in server_address;
        struct sockaddr_in client_address;

main()
{
	sem_init(&mutex,0,1);

	server_sockfd = socket( AF_INET , SOCK_STREAM, 0);

	server_address.sin_family = AF_INET;
	server_address.sin_addr.s_addr = htonl(INADDR_ANY);
	server_address.sin_port = htons(9734);
	server_len = sizeof(server_address);
	bind(server_sockfd, (struct sockaddr *)&server_address, server_len);
	listen(server_sockfd, 5);
	while(1){
pthread_create(&a_thread,NULL,thread_function,NULL);
pthread_join(a_thread,NULL);
	}
}
void *thread_function(void *arg)
{
                printf("server waiting\n");
                client_len = sizeof(client_address);
        client_sockfd = accept(server_sockfd,(struct sockaddr *)&client_address, &client_len);
 printf("accept request\n");
pthread_create(&a_thread,NULL,Client,(void *)&client_sockfd);
}
void *Client(void *arg)
{
char ch;
int a,b,re;
	int client_sockfd = ((int *)arg)[0];
sem_wait(&mutex);
count++;
sem_post(&mutex);
	read(client_sockfd, &ch, 1);
write(client_sockfd, &count, 4);
read(client_sockfd, &a, 4);
read(client_sockfd, &b, 4);
if(ch=='1')
re=a+b;
if(ch=='2')
re=a-b;
if(ch=='3')
re=a*b;
if(ch=='4')
re=a/b;
	write(client_sockfd, &re, 4);
	printf("processing finish\n");
	close(client_sockfd);
}