linux网络编程 | c | select实现多路IO转接服务器
poll实现多路IO转接服务器
基于该视频完成
通过响应式–多路IO转接实现
要求：能看懂看，看不懂也没啥大事，现在基本都用epoll代替了
大家看视频思路吧，代码就是从讲义里面copy了一份，因为不是很重要的东西
思路
代码实现
warp.h
#ifndef __WRAP_H_
#define __WRAP_H_
#include<sys/epoll.h>
//#include<event2/event.h>
#include<sys/select.h>
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<fcntl.h>
#include<errno.h>
#include<string.h>
#include<dirent.h>
#include<sys/stat.h>
#include<wait.h>
#include<sys/mman.h>
#include<signal.h>
#include<pthread.h>
#include<sys/socket.h>
#include<arpa/inet.h>
#include<ctype.h>
#include<strings.h>
#include<netinet/ip.h>
#define SRV_PORT 1234
void perr_exit(const char *s);
int Accept(int fd,struct sockaddr *sa,socklen_t * salenptr);
int Bind(int fd, const struct sockaddr *sa, socklen_t salen);
int Connect(int fd, const struct sockaddr *sa, socklen_t addrlen);
int Listen(int fd, int backlog);
int Socket(int family, int type, int protocol);
size_t Read(int fd, void *ptr, size_t nbytes);
ssize_t Write(int fd,const void *ptr,size_t nbytes);
int Close(int fd);
ssize_t Readn(int fd, void *vptr, size_t n);
ssize_t Writen(int fd, const void *vptr, size_t n);
ssize_t my_read(int fd, char *ptr);
ssize_t Readline(int fd, void *vptr, size_t maxlen);
#endif
warp.c
#include"warp.h"
void perr_exit(const char *s)
{
perror(s);
exit(1);
}
int Accept(int fd,struct sockaddr *sa,socklen_t * salenptr)
{
int n;
again:
if((n=accept(fd,sa,salenptr))<0)
{
if((errno==ECONNABORTED)||(errno==EINTR))
goto again;
else
perr_exit("accept error");
}
return n;
}
int Bind(int fd, const struct sockaddr *sa, socklen_t salen)
{
int n;
if((n=bind(fd,sa,salen))<0)
perr_exit("bind error");
return n;
}
int Connect(int fd, const struct sockaddr *sa, socklen_t addrlen)
{
int n;
n=connect(fd,sa,addrlen);
if(n<0)
{
perr_exit("connect error");
}
return n;
}
int Listen(int fd, int backlog)
{
int n;
if((n=listen(fd,backlog))<0)
perr_exit("listen error");
return n;
}
int Socket(int family, int type, int protocol)
{
int n;
if((n=socket(family,type,protocol))<0)
perr_exit("socket error");
return n;
}
size_t Read(int fd, void *ptr, size_t nbytes)
{
ssize_t n;
again:
if((n=read(fd,ptr,nbytes))==-1)
{
if(errno==EINTR)
goto again;
else
return -1;
}
return n;
}
ssize_t Write(int fd,const void *ptr,size_t nbytes)
{
ssize_t n;
again:
if((n=write(fd,ptr,nbytes))==-1)
{
if(errno==EINTR)
goto again;
else
return -1;
}
return 0;
}
int Close(int fd)
{
int n;
if((n=close(fd))==-1)
perr_exit("close error");
return n;
}
ssize_t Readn(int fd, void *vptr, size_t n)
{
size_t nleft;
ssize_t nread;
char *ptr;
ptr=vptr;
nleft=n;
while(nleft>0)
{
if((nread=read(fd,ptr,nleft))<0)
{
if(errno==EINTR)
nread=0;
else
return -1;
}
else if(nread==0)
break;
}
}
ssize_t Writen(int fd, const void *vptr, size_t n)
{
size_t nleft;
ssize_t nwritten;
char *ptr;
ptr=(char *)vptr;
nleft=n;
while(nleft>0)
{
if((nwritten=write(fd,ptr,nleft))<=0)
{
if(nwritten<0&&errno==EINTR)
nwritten=0;
else
return -1;
}
nleft-=nwritten;
ptr+=nwritten;
}
return n;
}
ssize_t my_read(int fd, char *ptr)
{
static int read_cnt;
static char *read_ptr;
static char read_buf[100];
if(read_cnt<=0)
{
again:
if((read_cnt=read(fd,read_buf,sizeof(read_buf)))<0)
{
if(errno==EINTR)
goto again;
return -1;
}else if(read_cnt==0)
return 0;
read_ptr=read_buf;
}
read_cnt--;
*ptr=*read_ptr++;
return 1;
}
ssize_t Readline(int fd, void *vptr, size_t maxlen)
{
ssize_t n,rc;
char c,*ptr;
ptr=vptr;
for(n=1;n<maxlen;n++)
{
if((rc=my_read(fd,&c))==1)
{
*ptr++=c;
if(c=='\n')
break;
}else if(rc==0)
{
*ptr=0;
return n-1;
}
else
return -1;
}
*ptr=0;
return n;
}
multi_poll_sever.c
1./* server.c */
2.#include <stdio.h>
3.#include <stdlib.h>
4.#include <string.h>
5.#include <netinet/in.h>
6.#include <arpa/inet.h>
7.#include <poll.h>
8.#include <errno.h>
9.#include "wrap.h"
10.
11.#define MAXLINE 80
12.#define SERV_PORT 6666
13.#define OPEN_MAX 1024
14.
15.int main(int argc, char *argv[])
16.{
17. int i, j, maxi, listenfd, connfd, sockfd;
18. int nready;
19. ssize_t n;
20. char buf[MAXLINE], str[INET_ADDRSTRLEN];
21. socklen_t clilen;
22. struct pollfd client[OPEN_MAX];
23. struct sockaddr_in cliaddr, servaddr;
24.
25. listenfd = Socket(AF_INET, SOCK_STREAM, 0);
26.
27. bzero(&servaddr, sizeof(servaddr));
28. servaddr.sin_family = AF_INET;
29. servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
30. servaddr.sin_port = htons(SERV_PORT);
31.
32. Bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
33.
34. Listen(listenfd, 20);
35.
36. client[0].fd = listenfd;
37. client[0].events = POLLRDNORM; /* listenfd监听普通读事件 */
38.
39. for (i = 1; i < OPEN_MAX; i++)
40. client[i].fd = -1; /* 用-1初始化client[]里剩下元素 */
41. maxi = 0; /* client[]数组有效元素中最大元素下标 */
42.
43. for ( ; ; ) {
44. nready = poll(client, maxi+1, -1); /* 阻塞 */
45. if (client[0].revents & POLLRDNORM) { /* 有客户端链接请求 */
46. clilen = sizeof(cliaddr);
47. connfd = Accept(listenfd, (struct sockaddr *)&cliaddr, &clilen);
48. printf("received from %s at PORT %d\n",
49. inet_ntop(AF_INET, &cliaddr.sin_addr, str, sizeof(str)),
50. ntohs(cliaddr.sin_port));
51. for (i = 1; i < OPEN_MAX; i++) {
52. if (client[i].fd < 0) {
53. client[i].fd = connfd; /* 找到client[]中空闲的位置，存放accept返回的connfd */
54. break;
55. }
56. }
57.
58. if (i == OPEN_MAX)
59. perr_exit("too many clients");
60.
61. client[i].events = POLLRDNORM; /* 设置刚刚返回的connfd，监控读事件 */
62. if (i > maxi)
63. maxi = i; /* 更新client[]中最大元素下标 */
64. if (--nready <= 0)
65. continue; /* 没有更多就绪事件时,继续回到poll阻塞 */
66. }
67. for (i = 1; i <= maxi; i++) { /* 检测client[] */
68. if ((sockfd = client[i].fd) < 0)
69. continue;
70. if (client[i].revents & (POLLRDNORM | POLLERR)) {
71. if ((n = Read(sockfd, buf, MAXLINE)) < 0) {
72. if (errno == ECONNRESET) { /* 当收到 RST标志时 */
73. /* connection reset by client */
74. printf("client[%d] aborted connection\n", i);
75. Close(sockfd);
76. client[i].fd = -1;
77. } else {
78. perr_exit("read error");
79. }
80. } else if (n == 0) {
81. /* connection closed by client */
82. printf("client[%d] closed connection\n", i);
83. Close(sockfd);
84. client[i].fd = -1;
85. } else {
86. for (j = 0; j < n; j++)
87. buf[j] = toupper(buf[j]);
88. Writen(sockfd, buf, n);
89. }
90. if (--nready <= 0)
91. break; /* no more readable descriptors */
92. }
93. }
94. }
95. return 0;
96.}
原文地址：https://blog.csdn.net/m0_74795952/article/details/144437833
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