本文介绍了的Winsock recvfrom的设置超时的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想建立一个阻塞套接字后试图给recvfrom()的端口16毫秒超时。平台是Windows。我在万吨的例子在网上看了,似乎很简单我只是似乎无法得到它的工作。任何帮助将是AP preciated!
的#include< winsock2.h>
#包括LT&;串GT;的#pragma评论(LIB,WS2_32.LIB)#定义PORT_NUM 8001INT主要(无效)
{
标准::字符串localIP;
SOCKADDR_IN localAddr;
SOCKADDR_IN remoteAddr;
hostent *本地主机;
字符缓冲区[1024];
WSADATA wsData; INT结果=调用WSAStartup(MAKEWORD(2,2),放大器; wsData); // winsock的第2版 本地主机=的gethostbyname();
localIP = INET_NTOA(*(in_addr结构*)* localhost-> h_addr_list); localAddr.sin_family = AF_INET;
localAddr.sin_port = htons(PORT_NUM); //设定的端口号
localAddr.sin_addr.s_addr = inet_addr(localIP.c_str()); //设置IP地址 INT mHandle = WSASocket(AF_INET,SOCK_DGRAM,IPPROTO_UDP,NULL,0,0); 如果(mHandle == INVALID_SOCKET)
返回1;
如果(绑定(mHandle,(SOCKADDR *)及localAddr,sizeof的(localAddr))== SOCKET_ERROR)
返回1; 的timeval电视;
tv.tv_sec = 0;
tv.tv_usec = 1600; //为recv调用设置超时
如果(setsockopt的(mHandle,SOL_SOCKET,SO_RCVTIMEO,
reinter pret_cast<字符*>(安培;电视)的sizeof(timeval中)))
返回1; INT长度= sizeof的(remoteAddr); //< - 在这里永远块
recvfrom的(mHandle,缓冲器,1024,0,(SOCKADDR *)及remoteAddr,&放大器;长度); 返回0;
}/ *我也试过路过的时候,像这样:
诠释毫秒= 16;如果(setsockopt的(mHandle,SOL_SOCKET,SO_RCVTIMEO,reinter pret_cast<字符*>(安培; MS)的sizeof(INT)))
返回1; * /
解决方案
我看着select函数和劳拉说我应该做的,并得到了它真正轻松地工作!谢谢!
FD_SET FDS;
INT N;
timeval结构电视;//设置文件描述符集。
FD_ZERO(安培; FDS);
FD_SET(mHandle,&安培; FDS);//设置了超时的timeval结构。
tv.tv_sec = 10;
tv.tv_usec = 0;//等到超时或接收的数据。
N =选择(mHandle,&安培; FDS,NULL,NULL,&安培;电视);
如果(N == 0)
{
的printf(超时.. \\ n);
返回0;
}
否则,如果(N == -1)
{
的printf(错误.. \\ n);
返回1;
}INT长度= sizeof的(remoteAddr);recvfrom的(mHandle,缓冲器,1024,0,(SOCKADDR *)及remoteAddr,&放大器;长度);
I'm trying to set up a blocking socket to timeout after 16 ms of trying to recvfrom() on a port. Platform is Windows. I've looked at tons of examples online and it seems really simple I just can't seem to get it to work. Any help would be appreciated!
#include <winsock2.h>
#include <string>
#pragma comment(lib, "ws2_32.lib")
#define PORT_NUM 8001
int main(void)
{
std::string localIP;
sockaddr_in localAddr;
sockaddr_in remoteAddr;
hostent* localhost;
char buffer[1024];
WSADATA wsData;
int result = WSAStartup(MAKEWORD(2,2), &wsData); // winsock version 2
localhost = gethostbyname("");
localIP = inet_ntoa(*(in_addr*)*localhost->h_addr_list);
localAddr.sin_family = AF_INET;
localAddr.sin_port = htons(PORT_NUM); // Set Port Number
localAddr.sin_addr.s_addr = inet_addr(localIP.c_str()); // Set IP Address
int mHandle = WSASocket(AF_INET, SOCK_DGRAM, IPPROTO_UDP, NULL, 0, 0);
if(mHandle == INVALID_SOCKET)
return 1;
if(bind(mHandle, (SOCKADDR*)&localAddr, sizeof(localAddr)) == SOCKET_ERROR)
return 1;
timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 1600;
// Set Timeout for recv call
if(setsockopt(mHandle, SOL_SOCKET, SO_RCVTIMEO,
reinterpret_cast<char*>(&tv), sizeof(timeval)))
return 1;
int length = sizeof(remoteAddr);
// <-- Blocks here forever
recvfrom(mHandle, buffer, 1024, 0, (SOCKADDR*)&remoteAddr, &length);
return 0;
}
/* I've also tried passing the time like so:
int ms = 16;
if(setsockopt(mHandle, SOL_SOCKET, SO_RCVTIMEO, reinterpret_cast<char*>(&ms), sizeof(int)))
return 1; */
解决方案
I looked into the select function and as laura said I should do and got it to work real easily! Thanks!
fd_set fds ;
int n ;
struct timeval tv ;
// Set up the file descriptor set.
FD_ZERO(&fds) ;
FD_SET(mHandle, &fds) ;
// Set up the struct timeval for the timeout.
tv.tv_sec = 10 ;
tv.tv_usec = 0 ;
// Wait until timeout or data received.
n = select ( mHandle, &fds, NULL, NULL, &tv ) ;
if ( n == 0)
{
printf("Timeout..\n");
return 0 ;
}
else if( n == -1 )
{
printf("Error..\n");
return 1;
}
int length = sizeof(remoteAddr);
recvfrom(mHandle, buffer, 1024, 0, (SOCKADDR*)&remoteAddr, &length);
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