我正在构建一个套接字客户端,我需要为协议本身(缺少答案等)实现连接,读取,写入和超时超时。套接字连接从分离的线程中止
我正在考虑在分离的线程中使用一个简单的计时器,该计时器将在每个事务中启动,然后在事务完成时取消。这种方法将用于使用不同超时的协议控制。
为了测试我做了如下简单的代码:
#include <string>
#include <sstream>
#include <map>
#include <iostream>
#include <cstring>
#include <thread>
#ifdef _WIN32
#include <io.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <Windows.h>
#else
#include <unistd.h>
#include <sys/socket.h>
#include <netdb.h>
#include <sys/types.h>
#endif
#include <stdio.h>
#include <stdlib.h>
bool timerOn = false;
int currentSocket = 0;
void Timer(int seconds)
{
int tick = seconds;
while (tick > 0)
{
std::this_thread::sleep_for(std::chrono::seconds(1));
tick--;
}
if (timerOn)
close(currentSocket);
}
void StartTimer(int seconds)
{
timerOn = true;
std::thread t(&Timer, seconds);
t.detach();
}
void StopTimer()
{
timerOn = false;
}
void Connect(std::string address, int port)
{
struct addrinfo hints;
struct addrinfo *result = NULL;
struct addrinfo *rp = NULL;
int sfd, s;
std::memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC; /* Allow IPV4 or IPV6 */
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = 0;
hints.ai_protocol = 0;
std::string portStr;
portStr = std::to_string(port);
s = getaddrinfo(address.c_str(), portStr.c_str(), &hints, &result);
if (s != 0)
{
std::stringstream ss;
ss << "Cannot resolve hostname " << address << gai_strerror(s);
throw std::runtime_error(ss.str());
}
for (rp = result; rp != NULL; rp = rp->ai_next)
{
sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
if (sfd == -1)
continue;
StartTimer(10);
int sts = connect(sfd, rp->ai_addr, rp->ai_addrlen);
StopTimer();
if (sts == 0)
break;
close(sfd);
}
freeaddrinfo(result); /* Object no longer needed */
if (rp == NULL)
{
std::stringstream ss;
ss << "Cannot find server address at " << address << " port " << port;
throw std::runtime_error(ss.str());
}
currentSocket = sfd;
}
int main()
{
try
{
Connect("192.168.0.187", 9090);
std::cout << "Connected to server. Congrats!!!" << std::endl;
}
catch (std::exception& ex)
{
std::cout << "Error connecting to server. Aborting." << std::endl;
std::cout << ex.what() << std::endl;
}
}
关闭定时器插座不取消“连接”的操作,迫使其与错误中止。我也试过shutdown(sfd, SHUT_RDWR);
没有成功...
我的方法无效吗?为什么它不起作用?
如何强制connect
中止与分离线程错误?
并非所有平台都允许通过简单地关闭套接字来中断connect()。 –
@RemyLebeau我知道没有人会这样做。它有时可能发生运气,但几乎不可能保证。(仅仅使用常规的'socket','connect','close' API,它实际上是无法完成的。您需要一个具有附加功能的API,例如原子“连接然后解锁”功能。) –
@DavidSchwartz Windows允许通过关闭套接字来中止连接()。 –