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137 lines (130 loc) · 3.65 KB
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Copy pathserver_poll.c
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137 lines (130 loc) · 3.65 KB
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#include <sys/time.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <sys/wait.h>
#include <poll.h>
#define IPADDRESS "127.0.0.1"
#define PORT 6666
#define MAXLINE 1024
#define LISTENQ 5
#define OPEN_MAX 1000
#define INFTIM -1
int bind_and_listen() {
int servfd;
struct sockaddr_in my_addr;
unsigned int sin_size;
if((servfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
perror("socket");
return -1;
}
printf("socket ok \n");
my_addr.sin_family = AF_INET;
my_addr.sin_port = htons(PORT);
my_addr.sin_addr.s_addr = INADDR_ANY;
bzero(&(my_addr.sin_zero), 0);
if(bind(servfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1){
perror("bind");
return -2;
}
printf("bind ok \n");
if(listen(servfd, LISTENQ) == -1){
perror("listen");
return -3;
}
printf("listen ok \n");
return servfd;
}
void do_poll(int listenfd){
int connfd, sockfd;
struct sockaddr_in client_addr;
socklen_t client_addr_len;
struct pollfd client_fds[OPEN_MAX];
int max = 0;
int nready;
client_fds[0].fd = listenfd;
client_fds[0].events = POLLIN;
for(int i = 1; i < OPEN_MAX; ++i)
client_fds[i].fd = -1;
while(1){
// 有新client接入时先判断是否在比较大的下标位置，是的话修改max，否则不用更新
nready = poll(client_fds, max + 1, INFTIM);
if(nready == -1){
perror("poll error");
exit(1);
}
// 有新连接时必须接受，获得新fd，并将新fd放到数组中
if(client_fds[0].revents & POLLIN){
client_addr_len = sizeof(client_addr);
// 建立新连接
if((connfd = accept(listenfd, (struct sockaddr *)&client_addr, &client_addr_len)) == -1){
if(errno == EINTR)
continue;
else{
perror("accept error");
exit(1);
}
}
// 打印新连接的IP + port
fprintf(stdout, "accept a new client : %s:%d \n", inet_ntoa(client_addr.sin_addr), client_addr.sin_port);
// 将新的描述符添加到数组中（选取client_fds[0]之外数组中第一个未使用槽）
for(int i = 1; i < OPEN_MAX; i++){
if(client_fds[i].fd < 0){
max = (i > max ? i : max);
// 判断是否到了最大连接数
if(max == OPEN_MAX){
fprintf(stderr, "too many clients. \n");
exit(1);
}
printf("current connection num = %d\n", max);
// 添加至读描述符集合
client_fds[i].fd = connfd;
client_fds[i].events = POLLIN;
printf("already add !\n");
break;
}
}
// 记录客户连接套接字个数
if(--nready <= 0)
continue;
}
char buff[MAXLINE];
memset(buff, 0, MAXLINE);
int readlen = 0;
for(int i = 1; i <= max; i++){
// 寻找集合中已存在描述符并测试客户端描述符是否准备好
if(client_fds[i].fd < 0)
continue;
if(client_fds[i].revents & POLLIN){
// 客户端准备好则接受客户端发送的信息
readlen = read(client_fds[i].fd, buff, MAXLINE);
// 返回0表示EOF，结束读取，清除该描述符
if(readlen == 0){
close(client_fds[i].fd);
client_fds[i].fd = -1;
continue;
}
// 向客户端发送buff
write(STDOUT_FILENO, buff, readlen);
write(client_fds[i].fd, buff, readlen);
}
}
}
}
int main(int argc, char *argv[]){
int listenfd = bind_and_listen();
if(listenfd < 0)
return 0;
do_poll(listenfd);
return 0;
}