UDP套接字
在前一夜的复习中实现了一个C/S架构的TCP套接字demo。今天首先通过创建一个UDP的套接字例子来区分UDP Socket和TCP Socket的使用区别。
客户端:
1 | /* |
服务端:
1 | /* |
TCP Socker Server
本例以一个简单的http server来演示socket server构建:1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66/*
* 编译:gcc -m32 -o http_server http_server.c
* 运行:./http_server 8080
*/
#include <stdio.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netinet/in.h>
#define MAXPENDING 5 /* Max connection requests */
#define BUFFSIZE 32
void Die(char *mess) { perror(mess); exit(1); }
void HandleClient(int sock) {
char buffer[BUFFSIZE];
char response[] = "HTTP/1.1 200 OK\nConnection: close\n\n<html><head><title>Test</title></head><body><h1>Test</h1></body></html>\n\n";
send(sock, response, sizeof(response), 0);
close(sock);
}
int main(int argc, char *argv[]) {
int serversock, clientsock;
struct sockaddr_in echoserver, echoclient;
if (argc != 2) {
fprintf(stderr, "USAGE: echoserver <port>\n");
exit(1);
}
/* Create the TCP socket */
if ((serversock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
Die("Failed to create socket");
}
/* Construct the server sockaddr_in structure */
memset(&echoserver, 0, sizeof(echoserver)); /* Clear struct */
echoserver.sin_family = AF_INET; /* Internet/IP */
echoserver.sin_addr.s_addr = htonl(INADDR_ANY); /* Incoming addr */
echoserver.sin_port = htons(atoi(argv[1])); /* server port */
/* Bind the server socket */
if (bind(serversock, (struct sockaddr *) &echoserver,
sizeof(echoserver)) < 0) {
Die("Failed to bind the server socket");
}
/* Listen on the server socket */
if (listen(serversock, MAXPENDING) < 0) {
Die("Failed to listen on server socket");
}
/* Run until cancelled */
while (1) {
unsigned int clientlen = sizeof(echoclient);
/* Wait for client connection */
if ((clientsock = accept(serversock, (struct sockaddr *) &echoclient, &clientlen)) < 0) {
Die("Failed to accept client connection");
}
fprintf(stdout, "Client connected: %s\n", inet_ntoa(echoclient.sin_addr));
HandleClient(clientsock);
}
}
阻塞套接字与非阻塞套接字
在阻塞的套接字中,服务端接收到的请求需要排队对其进行处理,这就形成了套接字阻塞。为了解决套接字阻塞的问题,可以创建非阻塞的服务端模型。
一个在网上找的非阻塞套接字的例子:
1 | /*************************************************************************** |
多线程非阻塞套接字
待后续补充。
参考资料
Linux socket 编程,第一部分
Linux socket 编程,第二部分
Linux下的socket演示程序
编写一个单进程非阻塞多客户的套接字客户端