sockets

问题 I need to implement following behavior: when server starts, it should check for existing servers using broadcast. Then it waits for answer. But, how to set any timeout for waiting? int optval = 1; char buff[BUFF_SIZE]; SOCKADDR_IN addr; int length = sizeof(addr); if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, (char*)&optval, sizeof(optval)) == SOCKET_ERROR) throw(errors::SETSOCKOPT); addr->sin_family = AF_INET; addr->sin_port = htons(this->serverPort); addr->sin_addr.s_addr = INADDR_ANY; sendto

问题 I need to implement following behavior: when server starts, it should check for existing servers using broadcast. Then it waits for answer. But, how to set any timeout for waiting? int optval = 1; char buff[BUFF_SIZE]; SOCKADDR_IN addr; int length = sizeof(addr); if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, (char*)&optval, sizeof(optval)) == SOCKET_ERROR) throw(errors::SETSOCKOPT); addr->sin_family = AF_INET; addr->sin_port = htons(this->serverPort); addr->sin_addr.s_addr = INADDR_ANY; sendto

问题 My Unity project related with socket communication works fine on my Mac. I run a C# server on my own computer's terminal and then run the unity project. The unity project can connect to my server and receive the message sent by the server. Every thing works fine. However, when I Build and Run this unity project to my iPhone, it comes with some problems: 2016-12-26 12:43:43.915127 ProductName[8497:5717779] [DYMTLInitPlatform] platform initialization successful 2016-12-26 12:43:44.095512

问题 My Unity project related with socket communication works fine on my Mac. I run a C# server on my own computer's terminal and then run the unity project. The unity project can connect to my server and receive the message sent by the server. Every thing works fine. However, when I Build and Run this unity project to my iPhone, it comes with some problems: 2016-12-26 12:43:43.915127 ProductName[8497:5717779] [DYMTLInitPlatform] platform initialization successful 2016-12-26 12:43:44.095512

问题 Ever since I discovered sockets, I've been using the nonblocking variants, since I didn't want to bother with learning about threading. Since then I've gathered a lot more experience with threading, and I'm starting to ask myself.. Why would you ever use it for sockets? A big premise of threading seems to be that they only make sense if they get to work on their own set of data. Once you have two threads working on the same set of data, you will have situations such as: if(!hashmap.hasKey(

问题 I am a bit confused, about how to require and use modules in Node.js. My scenario is the following: I wrote a complete server in one single file, which uses Socket.io for realtime communication. Now the index.js became pretty big, and I want to split the code into several modules to make it more managable. For example I have some functions for serving a Survey to the clients, and getting back their answers. I put all those functions in a seperate module, and require it in the index.js. Works

问题 In my case, I need to run a socket client and server on the same computer. The udp socket client needs to bind local port to 1234, and will communicate with a socker server on remote side. While an udp socket server in the same computer needs to bind local port to 1234 as well, and will communicate with a socket client on remote side as well. Is it feasible? Any potential issue or notice? Thanks! 回答1: If you are using multicast or broadcast UDP communication, then it often makes sense to bind

问题 I'm trying to find the owner socket of an sk_buff instance, say, skb . My ultimate goal is to find a specific TCP option and somehow let the user space application to know. I plan to set a socket option when I find the TCP option and let the user space app to call getsockopt() . Therefore I need to know the ownership between sk_buff and sock . I find there is a field in sk_buff: struct sock *sk; However, when I try to retrieve this field at tcp_parse_options in tcp_input.c , I always get skb-

问题 I'm trying to connect to an rabbitMQ server but the it keeps failing on connection with a socket.error: protocol not found error. In [1]: import pika In [2]: pika.BlockingConnection(pika.ConnectionParameters('ip_of_server')) with error output of --------------------------------------------------------------------------- error Traceback (most recent call last) <ipython-input-2-7adc44418966> in <module>() ----> 1 pika.BlockingConnection(pika.ConnectionParameters('localhost') 2 ) /usr/lib

问题 In Python when we want to make a script that listens for multicast traffic we set the IP_ADD_MEMBERSHIP option of the socket with a value that consists of the multicast group address and the address of a local interface on which it will listen for the group's traffic. Many examples on the Internet pass to IP_ADD_MEMBERSHIP the INADDR_ANY wildcard address as the local interface, and some of them state that this will make the socket to listen on all interfaces for multicast packets. However the