Search Results

Search found 1680 results on 68 pages for 'berkeley sockets'.

Page 10/68 | < Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >

  • C++ Winsock non-blocking/async UDP socket

    - by Ragnagard
    Hi all! I'm developping a little data processor in c++ over UDP sockets, and have a thread (just one, and apart the sockets) that process the info received from them. My problem happens when i need to receive info from multiple clients in the socket at the same time. How could i do something like: Socket foo; /* init socket vars and attribs */ while (serving){ thread_processing(foo_info); } for multiple clients (many concurrent access) in c++? I'm using winsocks atm on win32, but just get standard blocking udp sockets working. No gui, it's a console app. I'll appreciate so much an example or pointer to one ;). Thanks in advance.

    Read the article

  • Linux and I/O completion ports?

    - by someguy
    Using winsock, you can configure sockets or seperate I/O operations to "overlap". This means that calls to perform I/O are returned immediately, while the actual operations are completed asynchronously by separate worker threads. Winsock also provides "completion ports". From what I understand, a completion port acts as a multiplexer of handles (sockets). A handle can be demultiplexed if it isn't in the middle of an I/O operation, i.e. if all its I/O operations are completed. So, on to my question... does linux support completion ports or even asynchronous I/O for sockets?

    Read the article

  • How to implement file transfer with Java sockets?

    - by ZeKoU
    Hello, I am working on a chat implementation with Java sockets. I have focused on few functionalities, like authentication, one person chat and a group chat. I was thinking about adding file transfer functionality, and I wonder what's the good practice about this. Should I have separate socket on the server with different port listening just for file transfers? Right now input and output streams that I get from server socket are binded to Scanner and PrintWriter objects respectively, so I find it hard to use that for file transfer. Any patterns you guys could recommend or give me good recommendations are very appreciated. Thanks, ZeKoU

    Read the article

  • AIO network sockets and zero-copy under Linux

    - by remyhorton
    I have been experimenting with async Linux network sockets (aio_read et al in aio.h/librt), and one thing i have been trying to find out is whether these are zero-copy or not. Pretty much all i have read so far discusses file I/O, whereas its network I/O i am interested in. AIO is a bit of a pain to use and i suspect is non-portable, so wondering whether its worth persevering with it. Zero-copy is just about the only advantage (albiet a major one for my purposes) it would have over (non-blocking) select/epoll..

    Read the article

  • How to pass sockets created to another Java Process

    - by whoi
    Hi; We have an application which creates many sockets which belongs to its thread, By design if this application somehow fails, all threads stop which is not wanted. So to overcome this issue, each thread must be separated from the main application, if one of the threads fails, the other ones should be running. One thing in our mind is to pass created socket to another java process, so what is the correct way? An other approach also is welcome? Waiting for your suggestions...

    Read the article

  • full duplex communication over the web w/o flash sockets

    - by aharon
    A web application I'm helping to develop is faced with a well-known problem: we want to be able to let users know of various events and so forth that can occur at any time, essentially at random, and update their view accordingly. Essentially, we need to allow the server to push requests to individual clients, as opposed to the client asking the server. I understand that WebSockets are an effort to address the problem; however, after a bit of looking around into them, I understand that a) very few web browsers currently offer native websocket support; b) to get around this, you either use flash sockets or some sort of AJAX long-polling; c) a special websockets server must be used. Now, we want to offer our service without Flash. And any sort of servers must have some sort of load-balancing capabilities, or at least some software that can do load balancing for them. As of 2008, everyone was saying that Comet-based solutions (e.g., Bayeux) were the way to go for these sort of situations. However, the various protocols seem to have not had much work put into them since then—which leads (finally) to the question. Is Bayeux-flavored Comet still the right tool for jobs like this? If not, what is?

    Read the article

  • Multiple HTTP requests using sockets in java

    - by codeomnitrix
    How could i send multiple http requests from my java program using sockets. actually i have tried as: import java.net.*; import java.io.*; class htmlPageFetch{ public static void main(String[] args){ try{ Socket s = new Socket("127.0.0.1", 80); DataInputStream dIn = new DataInputStream(s.getInputStream()); PrintWriter dOut = new PrintWriter(s.getOutputStream(), true); dOut.println("GET /mytesting/justCheck.html HTTP/1.1\r\nHost:localhost\r\n\r\n"); boolean more_data = true; String str; int i = 0; while(more_data){ str = dIn.readLine(); if(str==null){ //Now server has stopped sending data //So now write again the inputs dOut.println("GET /mytesting/justCheck1.html HTTP/1.1\r\nHost:localhost\r\n\r\n"); continue; } System.out.println(str); } }catch(IOException e){ } } } But when I send the request again it was not processed? Thank in advance.

    Read the article

  • "Address already in use" error from socket bind, when ports are not being used

    - by Ivan Novick
    I can not bind (using C or python sockets) to any port in the range: 59969-60000 Using lsof, netstat and fuser I do not see any processes using these ports. Other ports such as 59900-59968 and 60001-60009 I can bind to them. My OS: is CentOS release 5.5 (Final) 2.6.18-194.3.1.el5 There must be something missing? Anyone have any idea how to debug why this port range is not usable? Cheers, Ivan

    Read the article

  • How would one build a relational database on a key-value store, a-la Berkeley DB's SQL interface?

    - by coleifer
    I've been checking out Berkeley DB and was impressed to find that it supported a SQL interface that is "nearly identical" to SQLite. http://docs.oracle.com/cd/E17076_02/html/bdb-sql/dbsqlbasics.html#identicalusage I'm very curious, at a high-level, how this kind of interface might have been architected. For instance: since values are "transparent", how do you efficiently query and sort by value how are limits and offsets performed efficiently on large result sets how would the keys be structured and serialized for good average-case performance

    Read the article

  • Communication protocols in UDP

    - by Betamoo
    After many hours, I have discovered that the given udp server needs the following steps for a successful communication: 1- Send "Start Message" on a given port 2- Wait to receive from server on any port 3- Then the port dedicated to you to send further data to the server equals the port you have received on it + 1 So I am asking if this kind is a known protocol/handshaking, or it is only special to this server?? PS: All above communication were in udp sockets in C# PS: Related to a previous question: http://stackoverflow.com/questions/2757868/about-c-udp-sockets Thanks

    Read the article

  • Javascript: Writing a firefox extension with sockets

    - by Johnny Grass
    I need to write a firefox extension that creates a server socket (I think that's what it's called) and returns the browser's current url when a client application (running on the same computer) sends it a request. The thing is that I have no Java/Javascript background at all and I'm pressed for time so I am trying to hack something together from code samples. So far I've been mildly successful. I've been working with code from this question which is used in the open source Firefox exension PolyChrome I have the following code: var reader = { onInputStreamReady : function(input) { var input_stream = Components.classes["@mozilla.org/scriptableinputstream;1"] .createInstance(Components.interfaces.nsIScriptableInputStream); input_stream.init(input); input_stream.available(); var request = ''; while (input_stream.available()) { request = request + input_stream.read(512); } var checkString = "foo" if (request.toString() == checkString.toString()) { output_console('URL: ' + content.location.href); } else output_console("nothing"); var thread_manager = Components.classes["@mozilla.org/thread-manager;1"].getService(); input.asyncWait(reader,0,0,thread_manager.mainThread); } } var listener = { onSocketAccepted: function(serverSocket, clientSocket) { output_console("Accepted connection on "+clientSocket.host+":"+clientSocket.port); input = clientSocket.openInputStream(0, 0, 0).QueryInterface(Components.interfaces.nsIAsyncInputStream); output = clientSocket.openOutputStream(Components.interfaces.nsITransport.OPEN_BLOCKING, 0, 0); var thread_manager = Components.classes["@mozilla.org/thread-manager;1"].getService(); input.asyncWait(reader,0,0,thread_manager.mainThread); } } var serverSocket = Components.classes["@mozilla.org/network/server-socket;1"]. createInstance(Components.interfaces.nsIServerSocket); serverSocket.init(9999, true, 5); output_console("Opened socket on " + serverSocket.port); serverSocket.asyncListen(listener); I have a few questions. So far I can telnet into localhost and get a response, but my string comparison in the reader seems to fail even if I enter "foo". I don't get why. What am I missing? The sample code I'm using opens up a console window and prints output when I telnet into localhost. Ideally I would like the output to be returned as a response when the client sends a request to the server socket with a passphrase. How do I go about doing that? Is doing this a good idea? Does it create security vulnerabilities on the computer? How can I block connections to the socket from other computers? What is a good place to read about javascript sockets? My google searches have been pretty fruitless but then maybe I'm not using the right keywords.

    Read the article

  • What does it mean to flush a socket?

    - by User4748402
    I don't really know much about sockets except how to read and write to them as if they were files. I know a little about using socket selectors. I don't get why you have to flush a socket, what's actually happening there? The bits just hang out somewhere in memory until they get pushed off? I read some things online about sockets, but it's all very abstract and high level. What's actually happening here?

    Read the article

  • Socket.ReceiveAsync problem

    - by bartol
    Hi, I have a problem using SocketAsyncEventArgs model with .net sockets. Everything works great until the moment that the server wishes to close a client connection. I use following code for this: try { socket.Shutdown(SocketShutdown.Both); } catch { } // throws if client process has already closed finally { socket.Close(); } socket = null; Each connection is using two SocketAsyncEventArgs (one for send and one for receive) and after closing the connection they are returned to a pool from which they can be later reused. And here the problem starts, because when another connection is established and receive args are reused from the pool we get an exception: System.InvalidOperationException: "An asynchronous socket operation is already in progress using this SocketAsyncEventArgs instance."; at System.Net.Sockets.SocketAsyncEventArgs.StartOperationCommon(Socket socket) at System.Net.Sockets.Socket.ReceiveAsync(SocketAsyncEventArgs e) I've done some debugging and it appears that the connection closing code from the beginning of the question does not cancel Socket.ReceiveAsync operation that is in progress when the connection is closed. I've tried many combinations of Shutdown, Disconnect and Linger options for the socket but nothing worked. Any suggestions? Thanks

    Read the article

  • Web Sockets: Browser won't receive the message, complains about it not starting with 0x00 (byte)

    - by giggsey
    Here is my code: import java.net.*; import java.io.*; import java.util.*; import org.jibble.pircbot.*; public class WebSocket { public static int port = 12345; public static ArrayList<WebSocketClient> clients = new ArrayList<WebSocketClient>(); public static ArrayList<Boolean> handshakes = new ArrayList<Boolean>(); public static ArrayList<String> nicknames = new ArrayList<String>(); public static ArrayList<String> channels = new ArrayList<String>(); public static int indexNum; public static void main(String args[]) { try { ServerSocket ss = new ServerSocket(WebSocket.port); WebSocket.console("Created socket on port " + WebSocket.port); while (true) { Socket s = ss.accept(); WebSocket.console("New Client connecting..."); WebSocket.handshakes.add(WebSocket.indexNum,false); WebSocket.nicknames.add(WebSocket.indexNum,""); WebSocket.channels.add(WebSocket.indexNum,""); WebSocketClient p = new WebSocketClient(s,WebSocket.indexNum); Thread t = new Thread( p); WebSocket.clients.add(WebSocket.indexNum,p); indexNum++; t.start(); } } catch (Exception e) { WebSocket.console("ERROR - " + e.toString()); } } public static void console(String msg) { Date date = new Date(); System.out.println("[" + date.toString() + "] " + msg); } } class WebSocketClient implements Runnable { private Socket s; private int iAm; private String socket_res = ""; private String socket_host = ""; private String socket_origin = ""; protected String nick = ""; protected String ircChan = ""; WebSocketClient(Socket socket, int mynum) { s = socket; iAm = mynum; } public void run() { String client = s.getInetAddress().toString(); WebSocket.console("Connection from " + client); IRCclient irc = new IRCclient(iAm); Thread t = new Thread( irc ); try { Scanner in = new Scanner(s.getInputStream()); PrintWriter out = new PrintWriter(s.getOutputStream(),true); while (true) { if (! in.hasNextLine()) continue; String input = in.nextLine().trim(); if (input.isEmpty()) continue; // Lets work out what's wrong with our input if (input.length() > 3 && input.charAt(0) == 65533) { input = input.substring(2); } WebSocket.console("< " + input); // Lets work out if they authenticate... if (WebSocket.handshakes.get(iAm) == false) { checkForHandShake(input); continue; } // Lets check for NICK: if (input.length() > 6 && input.substring(0,6).equals("NICK: ")) { nick = input.substring(6); Random generator = new Random(); int rand = generator.nextInt(); WebSocket.console("I am known as " + nick); WebSocket.nicknames.set(iAm, "bo-" + nick + rand); } if (input.length() > 9 && input.substring(0,9).equals("CHANNEL: ")) { ircChan = "bo-" + input.substring(9); WebSocket.console("We will be joining " + ircChan); WebSocket.channels.set(iAm, ircChan); } if (! ircChan.isEmpty() && ! nick.isEmpty() && irc.started == false) { irc.chan = ircChan; irc.nick = WebSocket.nicknames.get(iAm); t.start(); continue; } else { irc.msg(input); } } } catch (Exception e) { WebSocket.console(e.toString()); e.printStackTrace(); } t.stop(); WebSocket.channels.remove(iAm); WebSocket.clients.remove(iAm); WebSocket.handshakes.remove(iAm); WebSocket.nicknames.remove(iAm); WebSocket.console("Closing connection from " + client); } private void checkForHandShake(String input) { // Check for HTML5 Socket getHeaders(input); if (! socket_res.isEmpty() && ! socket_host.isEmpty() && ! socket_origin.isEmpty()) { send("HTTP/1.1 101 Web Socket Protocol Handshake\r\n" + "Upgrade: WebSocket\r\n" + "Connection: Upgrade\r\n" + "WebSocket-Origin: " + socket_origin + "\r\n" + "WebSocket-Location: ws://" + socket_host + "/\r\n\r\n",false); WebSocket.handshakes.set(iAm,true); } return; } private void getHeaders(String input) { if (input.length() >= 8 && input.substring(0,8).equals("Origin: ")) { socket_origin = input.substring(8); return; } if (input.length() >= 6 && input.substring(0,6).equals("Host: ")) { socket_host = input.substring(6); return; } if (input.length() >= 7 && input.substring(0,7).equals("Cookie:")) { socket_res = "."; } /*input = input.substring(4); socket_res = input.substring(0,input.indexOf(" HTTP")); input = input.substring(input.indexOf("Host:") + 6); socket_host = input.substring(0,input.indexOf("\r\n")); input = input.substring(input.indexOf("Origin:") + 8); socket_origin = input.substring(0,input.indexOf("\r\n"));*/ return; } protected void send(String msg, boolean newline) { byte c0 = 0x00; byte c255 = (byte) 0xff; try { PrintWriter out = new PrintWriter(s.getOutputStream(),true); WebSocket.console("> " + msg); if (newline == true) msg = msg + "\n"; out.print(msg + c255); out.flush(); } catch (Exception e) { WebSocket.console(e.toString()); } } protected void send(String msg) { try { WebSocket.console(">> " + msg); byte[] message = msg.getBytes(); byte[] newmsg = new byte[message.length + 2]; newmsg[0] = (byte)0x00; for (int i = 1; i <= message.length; i++) { newmsg[i] = message[i - 1]; } newmsg[message.length + 1] = (byte)0xff; // This prints correctly..., apparently... System.out.println(Arrays.toString(newmsg)); OutputStream socketOutputStream = s.getOutputStream(); socketOutputStream.write(newmsg); } catch (Exception e) { WebSocket.console(e.toString()); } } protected void send(String msg, boolean one, boolean two) { try { WebSocket.console(">> " + msg); byte[] message = msg.getBytes(); byte[] newmsg = new byte[message.length+1]; for (int i = 0; i < message.length; i++) { newmsg[i] = message[i]; } newmsg[message.length] = (byte)0xff; // This prints correctly..., apparently... System.out.println(Arrays.toString(newmsg)); OutputStream socketOutputStream = s.getOutputStream(); socketOutputStream.write(newmsg); } catch (Exception e) { e.printStackTrace(); } } } class IRCclient implements Runnable { protected String nick; protected String chan; protected int iAm; boolean started = false; IRCUser irc; IRCclient(int me) { iAm = me; irc = new IRCUser(iAm); } public void run() { WebSocket.console("Connecting to IRC..."); started = true; irc.setNick(nick); irc.setVerbose(false); irc.connectToIRC(chan); } void msg(String input) { irc.sendMessage("#" + chan, input); } } class IRCUser extends PircBot { int iAm; IRCUser(int me) { iAm = me; } public void setNick(String nick) { this.setName(nick); } public void connectToIRC(String chan) { try { this.connect("irc.appliedirc.com"); this.joinChannel("#" + chan); } catch (Exception e) { WebSocket.console(e.toString()); } } public void onMessage(String channel, String sender,String login, String hostname, String message) { // Lets send this message to me WebSocket.clients.get(iAm).send(message); } } Whenever I try to send the message to the browser (via Web Sockets), it complains that it doesn't start with 0x00 (which is a byte). Any ideas? Edit 19/02 - Added the entire code. I know it's real messy and not neat, but I want to get it functioning first. Spend last two days trying to fix.

    Read the article

  • C# TCP Async EndReceive() throws InvalidOperationException ONLY on Windows XP 32-bit

    - by James Farmer
    I have a simple C# Async Client using a .NET socket that waits for timed messages from a local Java server used for automating commands. The messages come in asynchronously and is written to a ring buffer. This implementation seems to work fine on Windows Vista/7/8 and OSX, but will randomly throw this exception while it's receiving a message from the local Java server: Unhandled Exception: System.InvalidOperationException: EndReceive can only be called once for each asynchronous operation.     at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult, SocketError& errorCode)     at System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)     at SocketTest.Controller.RecvAsyncCallback(IAsyncResult ar)     at System.Net.LazyAsyncResult.Complete(IntPtr userToken)     ... I've looked online for this error, but have found nothing really helpful. This is the code where it seems to break: /// <summary> /// Callback to receive socket data /// </summary> /// <param name="ar">AsyncResult to pass to End</param> private void RecvAsyncCallback(IAsyncResult ar) { // The exception will randomly happen on this call int bytes = _socket.EndReceive(_recvAsyncResult); // check for connection closed if (bytes == 0) { return; } _ringBuffer.Write(_buffer, 0, bytes); // Checks buffer CheckBuffer(); _recvAsyncResult = _sock.BeginReceive(_buffer, 0, _buffer.Length, SocketFlags.None, RecvAsyncCallback, null); } The error doesn't happen on any particular moment except in the middle of receiving a message. The message itself can be any length for this to happen, and the exception can happen right away, or sometimes even up to a minute of perfect communication. I'm pretty new with sockets and network communication, and I feel I might be missing something here. I've tested on at least 8 different computers, and the only similarity with the computers that throw this exception is that their OS is Windows XP 32-bit.

    Read the article

  • Replace low level web-service reference call transport with custom one

    - by hoodoos
    I'm not sure if title sounds right actually, so I will give more explanation here. I will begin from very beginning :) I'm using c# and .net for my development. I have an application that makes requests to some soap web-service and for each user request it produces 3 to 10 requests for web-service, they should all run async to finish in one time, so I use Async method of the web-service generated reference and then wait for result on callback. But it seems like it starts a thread (or takes it from pool) for every async call I make, so if I have 10 clients I got to spawn 30 to 100 threads and it sounds terrible even for my 16 cores server :) So i wanted to replace low level transport implementation with my own which uses non-blocking sockets and can handle at least 50 sockets run parallel in one thread with not much overhead. But I actually dunno where to put my override best. I analyzed System.Web.Services.Protocols.SoapHttpClientProtocol class and see that it has some GetWebRequest method which I actually could use. If only I could somehow interupt the object it creates and get a http request with all headers and body from there and then send it with my own sockets.. Any ideas what approach to use? Or maybe there's something built in the framework I can use?

    Read the article

  • Forward local port or socket file to remote socket file

    - by Ninefingers
    Hi All, Quick question - I run two linux boxes, one my own desktop and the other my VPS. For security reasons on the VPS end I opted for socket connections to MySQL (/var/run/mysqld/mysql.sock). I know I can tunnel like this: ssh -L 3307:127.0.0.1:3306 [email protected] if I set up the remote sql server to listen on some port, but what I want to know is can I do something like: ssh -L /path/to/myremotesqlserver.sock:/var/run/mysqld/mysql.sock thereby tunnelling two sockets, as opposed to two ports? A perfectly acceptable solution would also be to forward a local port to the remote socket file, but where possible I'm trying not to have tcp servers running on the remote box. (and yes, I know tcp would be easier). Thanks all, Nf.

    Read the article

  • Raw socket sendto() failure in OS X

    - by user37278
    When I open a raw socket is OS X, construct my own udp packet (headers and data), and call sendto(), I get the error "Invalid Argument". Here is a sample program "rawudp.c" from the web site http://www.tenouk.com/Module43a.html that demonstrates this problem. The program (after adding string and stdlib #includes) runs under Fedora 10 but fails with "Invalid Argument" under OS X. Can anyone suggest why this fails in OS X? I have looked and looked and looked at the sendto() call, but all the parameters look good. I'm running the code as root, etc. Is there perhaps a kernel setting that prevents even uid 0 executables from sending packets through raw sockets in OS X Snow Leopard? Thanks.

    Read the article

  • Using mod_wsgi with mpm_itk: socket permission issue

    - by djechelon
    I'm using mod_itk as MPM for increased security in shared environment. I also have a Firefox Sync Server within one of the VHosts I host. That vhost is restricted to a certain user via AssignUserId user group. The problem is that the socket /var/run/wsgi...whatever.sock is chmodded srwx------ and owned by Apache's wwwrun. While I configured the vhost with WSGIProcessGroup sync WSGIDaemonProcess sync user=djechelon group=djechelon processes=1 threads=5 I still get the error that Apache wants to access a socket that is not accessible and because of this gets an error. Is it possible to configure mod_wsgi in order to create different sockets with different owners for different applications or to chmod its socket in a different way (less secure)? Currently, I'm running Firefox Sync as the only WSGI application. Moving it to a vhost that doesn't AssignUserId could solve this problem but will force me to change URL (and buy an additional SSL certificate), so I wouldn't consider this

    Read the article

  • How to set up memcached to use unix socket?

    - by alfish
    While I could use memcached on Debian to use the default 11211 port, but I've had great difficulty setting up unix socket, Form what I'v read, I know that I need to create a memcache.socket and add -s /path/to/memcache.socket -a 0766 To /etc/memcached.conf and comment out the default connection port and IP, i.e. -p 11211 -l 127.0.0.1 However, when I restart memcached I get internal server errors on Drupal site. I'm trying to implement unix sockets to avoid TCP/IP overhead and boost overal memcached performance, however not sure how much performance gain one can expect of this tweak. I appreciate your hints or possibly configs to to resolve this.

    Read the article

  • How to configure LAMP server for iOS social/chat app?

    - by andufo
    I'm on the last developing phase of a social networking app for iOS that has a chat module. Right now I'm trying to figure out the best way to achieve these features: Send message instantly to another user. If other user is online, delivery should be instantly. If user reads the message, the remitent should be notified of that action. If a user visits my profile, I should be notified instantly. What would be, in your opinion, the best approach to achieve that experience? The server is CentOS 5.6. I've previously reviewed XMPP, sockets, but I'm still unsure on what the best approach is. Any opinions and resources will be much appreciated.

    Read the article

  • How can 2 or more instances of the same program to communicate in local network?

    - by user1981437
    I want to create program which will be in use for few computers connected in local network. Basically the program aim is to keep track of all tables in a bar ( lets say ), which are reserved. When some user book a table as reserved the program should broadcast the table number to all other Pc's and mark the table as reserved. Since all computers use the same program, how is possible to create communication between all of them ? Should i use sockets to achieve this? If it matters, all of the computers have installed Linux OS,and the app will be developed in ruby,perl or php. Thank you.

    Read the article

  • socket connection failed, telnet OK

    - by cf16
    my problem is that I can't connect two comps through socket (windows xp and windows7) although the server created with socket is listening and I can telnet it. It receives then information and does what should be done, but if I run the corresponding socket client I get error 10061. Moreover I am behind firewall - these two comps are running within my LAN, the windows firewalls are turned off, comp1: 192.168.1.2 port 12345 comp1: 192.168.1.6 port 12345 router: 192.168.1.1 Maybe port forwarding could help? But most important for me is to answer why Sockets fail if telnet works fine. client: int main(){ // Initialize Winsock. WSADATA wsaData; int iResult = WSAStartup(MAKEWORD(2,2), &wsaData); if (iResult != NO_ERROR) printf("Client: Error at WSAStartup().\n"); else printf("Client: WSAStartup() is OK.\n"); // Create a socket. SOCKET m_socket; m_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (m_socket == INVALID_SOCKET){ printf("Client: socket() - Error at socket(): %ld\n", WSAGetLastError()); WSACleanup(); return 7; }else printf("Client: socket() is OK.\n"); // Connect to a server. sockaddr_in clientService; clientService.sin_family = AF_INET; //clientService.sin_addr.s_addr = inet_addr("77.64.240.156"); clientService.sin_addr.s_addr = inet_addr("192.168.1.5"); //clientService.sin_addr.s_addr = inet_addr("87.207.222.5"); clientService.sin_port = htons(12345); if (connect(m_socket, (SOCKADDR*)&clientService, sizeof(clientService)) == SOCKET_ERROR){ printf("Client: connect() - Failed to connect.\n"); wprintf(L"connect function failed with error: %ld\n", WSAGetLastError()); iResult = closesocket(m_socket); if (iResult == SOCKET_ERROR) wprintf(L"closesocket function failed with error: %ld\n", WSAGetLastError()); WSACleanup(); return 6; } // Send and receive data int bytesSent; int bytesRecv = SOCKET_ERROR; // Be careful with the array bound, provide some checking mechanism char sendbuf[200] = "Client: Sending some test string to server..."; char recvbuf[200] = ""; bytesSent = send(m_socket, sendbuf, strlen(sendbuf), 0); printf("Client: send() - Bytes Sent: %ld\n", bytesSent); while(bytesRecv == SOCKET_ERROR){ bytesRecv = recv(m_socket, recvbuf, 32, 0); if (bytesRecv == 0 || bytesRecv == WSAECONNRESET){ printf("Client: Connection Closed.\n"); break; }else printf("Client: recv() is OK.\n"); if (bytesRecv < 0) return 0; else printf("Client: Bytes received - %ld.\n", bytesRecv); } system("pause"); return 0; } server: int main(){ WORD wVersionRequested; WSADATA wsaData={0}; int wsaerr; // Using MAKEWORD macro, Winsock version request 2.2 wVersionRequested = MAKEWORD(2, 2); wsaerr = WSAStartup(wVersionRequested, &wsaData); if (wsaerr != 0){ /* Tell the user that we could not find a usable WinSock DLL.*/ printf("Server: The Winsock dll not found!\n"); return 0; }else{ printf("Server: The Winsock dll found!\n"); printf("Server: The status: %s.\n", wsaData.szSystemStatus); } /* Confirm that the WinSock DLL supports 2.2.*/ /* Note that if the DLL supports versions greater */ /* than 2.2 in addition to 2.2, it will still return */ /* 2.2 in wVersion since that is the version we */ /* requested. */ if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2 ){ /* Tell the user that we could not find a usable WinSock DLL.*/ printf("Server: The dll do not support the Winsock version %u.%u!\n", LOBYTE(wsaData.wVersion), HIBYTE(wsaData.wVersion)); WSACleanup(); return 0; }else{ printf("Server: The dll supports the Winsock version %u.%u!\n", LOBYTE(wsaData.wVersion), HIBYTE(wsaData.wVersion)); printf("Server: The highest version this dll can support: %u.%u\n", LOBYTE(wsaData.wHighVersion), HIBYTE(wsaData.wHighVersion)); } //////////Create a socket//////////////////////// //Create a SOCKET object called m_socket. SOCKET m_socket; // Call the socket function and return its value to the m_socket variable. // For this application, use the Internet address family, streaming sockets, and the TCP/IP protocol. // using AF_INET family, TCP socket type and protocol of the AF_INET - IPv4 m_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); // Check for errors to ensure that the socket is a valid socket. if (m_socket == INVALID_SOCKET){ printf("Server: Error at socket(): %ld\n", WSAGetLastError()); WSACleanup(); //return 0; }else{ printf("Server: socket() is OK!\n"); } ////////////////bind////////////////////////////// // Create a sockaddr_in object and set its values. sockaddr_in service; // AF_INET is the Internet address family. service.sin_family = AF_INET; // "127.0.0.1" is the local IP address to which the socket will be bound. service.sin_addr.s_addr = htons(INADDR_ANY);//inet_addr("127.0.0.1");//htons(INADDR_ANY); //inet_addr("192.168.1.2"); // 55555 is the port number to which the socket will be bound. // using the htons for big-endian service.sin_port = htons(12345); // Call the bind function, passing the created socket and the sockaddr_in structure as parameters. // Check for general errors. if (bind(m_socket, (SOCKADDR*)&service, sizeof(service)) == SOCKET_ERROR){ printf("Server: bind() failed: %ld.\n", WSAGetLastError()); closesocket(m_socket); //return 0; }else{ printf("Server: bind() is OK!\n"); } // Call the listen function, passing the created socket and the maximum number of allowed // connections to accept as parameters. Check for general errors. if (listen(m_socket, 1) == SOCKET_ERROR) printf("Server: listen(): Error listening on socket %ld.\n", WSAGetLastError()); else{ printf("Server: listen() is OK, I'm waiting for connections...\n"); } // Create a temporary SOCKET object called AcceptSocket for accepting connections. SOCKET AcceptSocket; // Create a continuous loop that checks for connections requests. If a connection // request occurs, call the accept function to handle the request. printf("Server: Waiting for a client to connect...\n"); printf("***Hint: Server is ready...run your client program...***\n"); // Do some verification... while (1){ AcceptSocket = SOCKET_ERROR; while (AcceptSocket == SOCKET_ERROR){ AcceptSocket = accept(m_socket, NULL, NULL); } // else, accept the connection... note: now it is wrong implementation !!!!!!!! !! !! (only 1 char) // When the client connection has been accepted, transfer control from the // temporary socket to the original socket and stop checking for new connections. printf("Server: Client Connected! Mammamija. \n"); m_socket = AcceptSocket; char recvBuf[200]=""; char * rc=recvBuf; int bytesRecv=recv(m_socket,recvBuf,64,0); if(bytesRecv==0 || bytesRecv==WSAECONNRESET){ cout<<"server: connection closed.\n"; }else{ cout<<"server: recv() is OK.\n"; if(bytesRecv<0){ return 0; }else{ printf("server: bytes received: %ld.\n",recvBuf); } }

    Read the article

  • Remote Socket Read In Multi-Threaded Application Returns Zero Bytes or EINTR (104)

    - by user39891
    Hi. Am a c-coder for a while now - neither a newbie nor an expert. Now, I have a certain daemoned application in C on a PPC Linux. I use PHP's socket_connect as a client to connect to this service locally. The server uses epoll for multiplexing connections via a Unix socket. A user submitted string is parsed for certain characters/words using strstr() and if found, spawns 4 joinable threads to different websites simultaneously. I use socket, connect, write and read, to interact with the said webservers via TCP on their port 80 in each thread. All connections and writes seems successful. Reads to the webserver sockets fail however, with either (A) all 3 threads seem to hang, and only one thread returns -1 and errno is set to 104. The responding thread takes like 10 minutes - an eternity long:-(. *I read somewhere that the 104 (is EINTR?), which in the network context suggests that ...'the connection was reset by peer'; or (B) 0 bytes from 3 threads, and only 1 of the 4 threads actually returns some data. Isn't the socket read/write thread-safe? I use thread-safe (and reentrant) libc functions such as strtok_r, gethostbyname_r, etc. *I doubt that the said webhosts are actually resetting the connection, because when I run a single-threaded standalone (everything else equal) all things works perfectly right, but of course in series not parallel. There's a second problem too (oops), I can't write back to the client who connect to my epoll-ed Unix socket. My daemon application will hang and hog CPU 100% for ever. Yet nothing is written to the clients end. Am sure the client (a very typical PHP socket application) hasn't closed the connection whenever this is happening - no error(s) detected either. Any ideas? I cannot figure-out whatever is wrong even with Valgrind, GDB or much logging. Kindly help where you can.

    Read the article

< Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >