设置socket接收和发送超时的一种方式

Linux环境设置Socket接收和发送超时：
须如下定义：struct timeval timeout = {3,0};
//设置发送超时
setsockopt(socket，SOL_SOCKET,SO_SNDTIMEO，(char *)&timeout,sizeof(struct timeval));
//设置接收超时
setsockopt(socket，SOL_SOCKET,SO_RCVTIMEO，(char *)&timeout,sizeof(struct timeval));

另外常用的方式是使用select函数设置fd为读时间，并设置超时时间。

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <strings.h>
#include <string.h>
#include <thread>

#include <unistd.h>
extern char *optarg;
extern int optind, opterr, optopt;

#include <getopt.h>

#define LOG_ERROR my_printf

int my_printf(char *fmt, ...)
{
char buffer[1024];
va_list argptr;
int length = 0;

va_start(argptr, fmt);
length = vsnprintf(buffer,1024 ,fmt, argptr);
va_end(argptr);

printf("%s\n", buffer);

return (length + 1);
}

int start_client(const char *host, int port, const char *local_host = NULL)
{
int client_socket = socket(AF_INET,SOCK_STREAM,0);

if( client_socket < 0)
{
LOG_ERROR("Create socket failed, errno %d", errno);
return -1;
}

//设置一个socket地址结构server_addr,代表服务器的internet地址, 端口
struct sockaddr_in server_addr;
bzero(&server_addr,sizeof(server_addr));
server_addr.sin_family = AF_INET;
if(inet_aton(host,&server_addr.sin_addr) == 0)
{
LOG_ERROR("Server address inet_aton failed, errno %d!", errno);
return -1;
}

if (local_host != NULL)
{
sockaddr_in client_addr;
client_addr.sin_family = AF_INET;
client_addr.sin_addr.s_addr = inet_addr(local_host);

if (bind(client_socket,(struct sockaddr*)&client_addr, sizeof(client_addr)) == -1)
{
LOG_ERROR("\nBind client failed, local_host %s, errno %d, %s\n",
local_host, errno, strerror(errno));
close(client_socket);
return -1;
}

}

server_addr.sin_port = htons(port);
socklen_t server_addr_length = sizeof(server_addr);

//向服务器发起连接,连接成功后client_socket代表了客户机和服务器的一个socket连接
if(connect(client_socket,(struct sockaddr*)&server_addr, server_addr_length) < 0)
{
LOG_ERROR("Connect to %s:%d failed! error %d, %s", host, port, errno, strerror(errno));
close(client_socket);

return -1;
}

// write(client_socket, "Hello Server", strlen("Hello Server"));

return client_socket;
}

int main()
{
int sock = 0;
struct timeval timeout = {3,0};
int tm = 0;
int res = 0;
char buf[1024];

sock = start_client("127.0.0.1", 5050);

setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(struct timeval));

tm = time(0);
res = read(sock, buf, 1024);
fprintf(stderr, "Read timeout %d\n", time(0) - tm);

return 0;
}