Search Results

Search found 1931 results on 78 pages for 'bsd sockets'.

Page 34/78 | < Previous Page | 30 31 32 33 34 35 36 37 38 39 40 41  | Next Page >

  • Creating a simple java hash server

    - by Blankman
    Is it possible to create a simple server in Java that returns a response based on a given key? So it would be a simple program, that stores a hashmap and returns the result based on a key provided by the client. What would be the fasted implementation, to have it over HTTP or a socket? The client will be a web based application.

    Read the article

  • Best way to notify several java applets/applications of a change on a server

    - by Dustin
    I need to know the best (fastest) way to have a server (preferably a php based one, but a jsp/servlet one could be set up as well using google app engine) notify several java applets/applications that a change has occurred to the data. The way i am picturing this to work will be very similar to that of the way i think an online java game (like Runescape) works User 1: Changes data on server. Server: returns success to User 1, notifies connected computers of change. Connected Computer 1: processes change, returns success to server. Connected Computer 2: processes change, returns success to server. Connected Computer 3: processes change, returns success to server. Connected Computer 4: processes change, returns success to server. I am hoping to have this entire process complete in half a second, and not involve polling as there will be long durations of nothing, followed by a sudden moment where 4 events happen in succession.

    Read the article

  • Strange "cache" effect between client and server

    - by mark
    I use a Socket-based connection between Client and server with ObjectOutputStream. The objects serialized and exchanged have this structure: public class RichiestaSalvataggioArticolo implements Serializable { private ArticoloDati articolo; public RichiestaSalvataggioArticolo(ArticoloDati articolo) { this.articolo = articolo; } @Override public void ricevi(GestoreRichieste gestore) throws Exception { gestore.interpreta(this); } public ArticoloDati getArticolo() { return articolo; } } the issue is that when I try to exchange messages between C/S with incapsulated content very similar (ArticoloDati whom differ only in 2 fields out of 10), the Client sends an ArticoloDati, but the Server receives the previous one. Does the ObjectOutputStream implement some kind of cache or memory between the calls, that fails to recognize that my 2 objects are different because they are very similar?

    Read the article

  • Threading in client-server socket program - proxy sever

    - by crazyTechie
    I am trying to write a program that acts as a proxy server. Proxy server basically listens to a given port (7575) and sends the request to the server. As of now, I did not implement caching the response. The code looks like ServerSocket socket = new ServerSocket(7575); Socket clientSocket = socket.accept(); clientRequestHandler(clientSocket); I changed the above code as below: //calling the same clientRequestHandler method from inside another method. Socket clientSocket = socket.accept(); Thread serverThread = new Thread(new ConnectionHandler(client)); serverThread.start(); class ConnectionHandler implements Runnable { Socket clientSocket = null; ConnectionHandler(Socket client){ this.clientSocket = client; } @Override public void run () { try { PrxyServer.clientRequestHandler(clientSocket); } catch (Exception ex) { ex.printStackTrace(); } } } Using the code, I am able to open a webpage like google. However, if I open another web page even I completely receive the first response, I get connection reset by peer expection. 1. How can I handle this issue Can i use threading to handle different requests. Can someone give a reference where I look for example code that implements threading. Thanks. Thanks.

    Read the article

  • trying to WHOIS a site within IRC

    - by SourD
    if data.find('!whois') != -1: s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect(("com.whois-servers.net", 43)) s.send('www.msn.com' + "\r\n") response = '' while True: d = s.recv(4096) response += d if d == '': break s.send('PRIVMSG ' + chan + " " + response + '\r\n') s.close() when I type !whois on the channel, it doesnt do anything, I'm probably doing this wrong. Any help will be appreciate it. Thanks. Note: There's another socket already connected.

    Read the article

  • Get the number of packages transmitted per connection

    - by Daniel
    How do I get the number of packages transmitted per TCP connection? I am using Java, but i know I will have to fetch the number from the underlying OS, so this quastion applies to Linux and Windows operating systems and will have different answers for each of them, I assume. I need this information to profile the network load of an application which seems to send too many small packages by flushing the socket streams too often.

    Read the article

  • Convert a NSString

    - by zp26
    My situation is explained in the code below. I need to send via a socket NSString drawn from a TextBox Thank you very much NSString *string = fieldTesto.txt; // I Find an istruction for insert s string in to the CFSocketSend UInt8 message[] = "Hello world"; CFDataRef data = CFDataCreate(NULL, message, sizeof(message)); CFSocketSendData(s, NULL, data, 0); CFRelease(data);

    Read the article

  • Use of select or multithread for almost 80 or more clients?

    - by Tushar Goel
    I am working on one project in which i need to read from 80 or more clients and then write their o/p into a file continuously and then read these new data for another task. My question is what should i use select or multithreading? Also I tried to use multi threading using read/fgets and write/fputs call but as they are blocking calls and one operation can be performed at one time so it is not feasible. Any idea is much appreciated. update 1: I have tried to implement the same using condition variable. I able to achieve this but it is writing and reading one at a time.When another client tried to write then it cannot able to write unless i quit from the 1st thread. I do not understand this. This should work now. What mistake i am doing? Update 2: Thanks all .. I am able to succeeded to get this model implemented using mutex condition variable. updated Code is as below: **header file******* char *mailbox ; pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER ; pthread_cond_t writer = PTHREAD_COND_INITIALIZER; int main(int argc,char *argv[]) { pthread_t t1 , t2; pthread_attr_t attr; int fd, sock , *newfd; struct sockaddr_in cliaddr; socklen_t clilen; void *read_file(); void *update_file(); //making a server socket if((fd=make_server(atoi(argv[1])))==-1) oops("Unable to make server",1) //detaching threads pthread_attr_init(&attr); pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED); ///opening thread for reading pthread_create(&t2,&attr,read_file,NULL); while(1) { clilen = sizeof(cliaddr); //accepting request sock=accept(fd,(struct sockaddr *)&cliaddr,&clilen); //error comparison against failire of request and INT if(sock==-1 && errno != EINTR) oops("accept",2) else if ( sock ==-1 && errno == EINTR) oops("Pressed INT",3) newfd = (int *)malloc(sizeof(int)); *newfd = sock; //creating thread per request pthread_create(&t1,&attr,update_file,(void *)newfd); } free(newfd); return 0; } void *read_file(void *m) { pthread_mutex_lock(&lock); while(1) { printf("Waiting for lock.\n"); pthread_cond_wait(&writer,&lock); printf("I am reading here.\n"); printf("%s",mailbox); mailbox = NULL ; pthread_cond_signal(&writer); } } void *update_file(int *m) { int sock = *m; int fs ; int nread; char buffer[BUFSIZ] ; if((fs=open("database.txt",O_RDWR))==-1) oops("Unable to open file",4) while(1) { pthread_mutex_lock(&lock); write(1,"Waiting to get writer lock.\n",29); if(mailbox != NULL) pthread_cond_wait(&writer,&lock); lseek(fs,0,SEEK_END); printf("Reading from socket.\n"); nread=read(sock,buffer,BUFSIZ); printf("Writing in file.\n"); write(fs,buffer,nread); mailbox = buffer ; pthread_cond_signal(&writer); pthread_mutex_unlock(&lock); } close(fs); }

    Read the article

  • send and receive in socket [closed]

    - by user3696492
    I have trouble in sending an object through socket in c#, my client can send to server but server can't send to client, i think there is something wrong with the client. Server private void Form1_Load(object sender, EventArgs e) { CheckForIllegalCrossThreadCalls = false; Thread a = new Thread(connect); a.Start(); } private void sendButton_Click(object sender, EventArgs e) { client.Send(SerializeData(ShapeList[ShapeList.Count - 1])); } void connect() { try { server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); iep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 5555); server.Bind(iep); server.Listen(10); client = server.Accept(); while (true) { byte[] data = new byte[1024]; client.Receive(data); PaintObject a = (PaintObject)DeserializeData(data); ShapeList.Add(a); Invalidate(); } } catch (Exception ex) { MessageBox.Show(ex.Message); } } client private void Form1_Load(object sender, EventArgs e) { CheckForIllegalCrossThreadCalls = false; Thread a = new Thread(connect); a.Start(); } private void SendButton_Click(object sender, EventArgs e) { client.Send(SerializeData(ShapeList[ShapeList.Count - 1])); } void connect() { try { client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); iep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 5555); client.Connect(iep); while (true) { byte[] data = new byte[1024]; client.Receive(data); PaintObject a = (PaintObject)DeserializeData(data); ShapeList.Add(a); Invalidate(); } } catch (Exception ex) { MessageBox.Show(ex.Message); } }

    Read the article

  • Intercommunication between Java Chat Servers

    - by Pravingate
    I have a application in which I am using socket programming , having this(image) scenario. Where number of clients will try to connect Broadcast server. Now here I am managing load through LVS(Load balancer). so as a example shown in image, suppose 200 clients will wish to login for broadcast they will be distributed as 100 users on server 1 and another 100 users on server 2.clients will get connected to servers using TCP connection. Now I am maintaining user information on server side in arraylist which will be stored in heap memory,Now the problem is if client wish to broadcast to all logged in users, but that particular client is logged in server 1. and so client will not be able to broadcast another 100 users from server 2. Because both ther servers are unaware about each others state. please suggest to solve this scenario by whatever means you want.

    Read the article

  • Socket Performance C++ Or C#

    - by modernzombie
    I have to write an application that is essentially a proxy server to handle all HTTP and HTTPS requests from our server (web browsing, etc). I know very little C++ and am very comfortable writing the application features in C#. I have experimented with the proxy from Mentalis (socket proxy) which seems to work fine for small webpages but if I go to large sites like tigerdirect.ca and browse through a couple of layers it is very slow and sometimes requests don't complete and I see broken images and javascript errors. This happens with all of our vendor sites and other content heavy sites. Mentalis uses HTTP 1.0 which I know is not as efficient but should a proxy be that slow? What is an acceptable amount of performance loss from using a proxy? Would HTTP 1.1 make a noticeable difference? Would a C++ proxy be much faster than one in C#? Is the Mentalis code just not efficient? Would I be able to use a premade C++ proxy and import the DLL to C# and still get good performance or would this project call for all C++? Sorry if these are obvious questions but I have not done network programming before.

    Read the article

  • What host do I have to bind a listening socket to?

    - by herrturtur
    I used python's socket module and tried to open a listening socket using import socket import sys def getServerSocket(host, port): for r in socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket.SOCK_STREAM, 0, socket.AI_PASSIVE): af, socktype, proto, canonname, sa = r try: s = socket.socket(af, socktype, proto) except socket.error, msg: s = None continue try: s.bind(sa) s.listen(1) except socket.error, msg: s.close() s = None continue break if s is None: print 'could not open socket' sys.exit(1) return s Where host was None and port was 15000. The program would then accept connections, but only from connections on the same machine. What do I have to do to accept connections from the internet?

    Read the article

  • Socket connection to a telnet-based server hangs on read

    - by mixwhit
    I'm trying to write a simple socket-based client in Python that will connect to a telnet server. I can test the server by telnetting to its port (5007), and entering text. It responds with a NAK (error) or an AK (success), sometimes accompanied by other text. Seems very simple. I wrote a client to connect and communicate with the server, but it hangs on the first attempt to read the response. The connection is successful. Queries like getsockname and getpeername are successful. The send command returns a value that equals the number of characters I'm sending, so it seems to be sending correctly. But in the end, it always hangs when I try to read the response. I've tried using both file-based objects like readline and write (via socket.makefile), as well as using send and recv. With the file object I tried making it with "rw" and reading and writing via that object, and later tried one object for "r" and another for "w" to separate them. None of these worked. I used a packet sniffer to watch what's going on. I'm not versed in all that I'm seeing, but during a telnet session I can see my typed text and the server's text coming back. During my Python socket connection, I can see my text going to the server, but packets back don't seem to have any text in them. Any ideas on what I'm doing wrong, or any strategies to try? Here's the code I'm using (in this case, it's with send and recv): #!/usr/bin/python host = "localhost" port = 5007 msg = "HELLO EMC 1 1" msg2 = "HELLO" import socket import sys try: skt = socket.socket(socket.AF_INET, socket.SOCK_STREAM) except socket.error, e: print("Error creating socket: %s" % e) sys.exit(1) try: skt.connect((host,port)) except socket.gaierror, e: print("Address-related error connecting to server: %s" % e) sys.exit(1) except socket.error, e: print("Error connecting to socket: %s" % e) sys.exit(1) try: print(skt.send(msg)) print("SEND: %s" % msg) except socket.error, e: print("Error sending data: %s" % e) sys.exit(1) while 1: try: buf = skt.recv(1024) print("RECV: %s" % buf) except socket.error, e: print("Error receiving data: %s" % e) sys.exit(1) if not len(buf): break sys.stdout.write(buf)

    Read the article

  • Killing a thread while deleting an object

    - by viswanathan
    I have an application which does some socket communication with some hardwares. Assume for the particular hardware i have an object and this object intiates a thread which listens on a particular port number say 5001 infinitely until a connection is established. Now if i delete this obect is there anyway by which i can ensure that the thread that is listening on port number 5001 infinitely also gets destroyed.

    Read the article

  • How can I obtain the IP address of my server program?

    - by Dr Dork
    Hello! This question is related to another question I just posted. I'm prepping for a simple work project and am trying to familiarize myself with the basics of socket programming in a Unix dev environment. At this point, I have some basic server side code and client side code setup to communicate. Currently, my client code successfully connects to the server code and the server code sends it a test message, then both quit out. Perfect! That's exactly what I wanted to accomplish. Now I'm playing around with the functions used to obtain info about the two environments (server and client). I'd like to obtain my server program's IP address. Here's the code I currently have to do this, but it's not working... int sockfd; unsigned int len; socklen_t sin_size; char msg[]="test message"; char buf[MAXLEN]; int st, rv; struct addrinfo hints, *serverinfo, *p; struct sockaddr_storage client; char s[INET6_ADDRSTRLEN]; char ip[INET6_ADDRSTRLEN]; //zero struct memset(&hints,0,sizeof(hints)); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_STREAM; hints.ai_flags = AI_PASSIVE; //get the server info if((rv = getaddrinfo(NULL, SERVERPORT, &hints, &serverinfo ) != 0)){ perror("getaddrinfo"); exit(-1); } // loop through all the results and bind to the first we can for( p = serverinfo; p != NULL; p = p->ai_next) { //Setup the socket if( (sockfd = socket( p->ai_family, p->ai_socktype, p->ai_protocol )) == -1 ) { perror("socket"); continue; } //Associate a socket id with an address to which other processes can connect if(bind(sockfd, p->ai_addr, p->ai_addrlen) == -1){ close(sockfd); perror("bind"); continue; } break; } if( p == NULL ){ perror("Fail to bind"); } inet_ntop(p->ai_family, get_in_addr((struct sockaddr *)p->ai_addr), s, sizeof(s)); printf("Server has TCP Port %s and IP Address %s\n", SERVERPORT, s); and the output for the IP is always empty... server has TCP Port 21412 and IP Address :: any ideas for what I'm missing? thanks in advance for your help! this stuff is really complicated at first.

    Read the article

  • The Scala way to use one actor per socket connection

    - by Stefan
    I am wondering how it is possible to avoid one socket connection pr. thread in Scala. I have thought a lot about it, but I always end up with some code which is listening for incoming data for each client connection. The problem is that I want to develop an application which should simultanously handle perhaps a couple of thousand connections. However I will of course not want to create a thread for each connection because of the lack of scalability and context switching. What would be the "right" way to do this. In my world it should be possible to have one actor for each connection without the need to block one thread per actor.

    Read the article

  • A non-blocking server with java.io

    - by Jon
    Everybody knows that java IO is blocking, and java NIO is non-blocking. In IO you will have to use the thread per client pattern, in NIO you can use one thread for all clients. Now my question follows: is it possible to make a non-blocking design using only the Java IO api. (not NIO) I was thinking about a pattern like this (obviously very simplified); List<Socket> li; for (Socket s : li) { InputStream in = s.getInputStream(); byte[] data = in.available(); in.read(data); // processData(data); (decoding packets, encoding outgoing packets } Also note that the client will always be ready for reading data. What are your opinions on this? Will this be suitable for a server that should at least hold a few hundred of clients without major performance issues?

    Read the article

  • What is wrong with this Asynchronus task?

    - by bluebrain
    the method onPostExecute simply was not executed, I have seen 16 at LogCat but I can not see 16 in LogCAT. I tried to debug it, it seemed that it goes to the first line of the class (package line) after return statement. private class Client extends AsyncTask<Integer, Void, Integer> { protected Integer doInBackground(Integer... params) { Log.e(TAG,10+""); try { socket = new Socket(target, port); Log.e(TAG,11+""); oos = new ObjectOutputStream(socket.getOutputStream()); Log.e(TAG,14+""); ois = new ObjectInputStream(socket.getInputStream()); Log.e(TAG,15+""); } catch (UnknownHostException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } Log.e(TAG,16+""); return 1; } protected void onPostExecute(Integer result) { Log.e(TAG,13+""); try { Log.e(TAG,12+""); oos.writeUTF(key); Log.e(TAG,13+""); if (ois.readInt() == OKAY) { isConnected = true; Log.e(TAG,14+""); }else{ Log.e(TAG,15+""); isConnected = false; } } catch (IOException e) { e.printStackTrace(); isClosed = true; } } }

    Read the article

  • Best practice for secure socket connection.

    - by LnDCobra
    What is the best practice for a secure socket connection (without SSL). I will be moving sensitive data (logins/passwords/accounts) across TCP Socket connection, and wondering if there is a good/fast way of Encrypting/Decrypting and avoiding malicious injection.

    Read the article

  • Java socket bug on linux (0xFF sent, -3 received)

    - by Marius
    While working on a WebSocket server in Java I came across this strange bug. I've reduced it down to two small java files, one is the server, the other is the client. The client simply sends 0x00, the string Hello and then 0xFF (per the WebSocket specification). On my windows machine, the server prints the following: Listening byte: 0 72 101 108 108 111 recieved: 'Hello' While on my unix box the same code prints the following: Listening byte: 0 72 101 108 108 111 -3 Instead of receiving 0xFF it gets -3, never breaks out of the loop and never prints what it has received. The important part of the code looks like this: byte b = (byte)in.read(); System.out.println("byte: "+b); StringBuilder input = new StringBuilder(); b = (byte)in.read(); while((b & 0xFF) != 0xFF){ input.append((char)b); System.out.print(b+" "); b = (byte)in.read(); } inputLine = input.toString(); System.out.println("recieved: '" + inputLine+"'"); if(inputLine.equals("bye")){ break; } I've also uploaded the two files to my server: Server.java Client.java My Windows machine is running windows 7 and my Linux machine is running Debian

    Read the article

  • More Poll() ?'s

    - by ultifinitus
    Back again! I've been doing some async socket programming with select() on windows,and it's been working quite well. However it's only scalable up to 1024 clients.Poll() is the way to get around that limitation, and I know it works on both linux and unix. But it doesn't work with a windows system correct? I read about WsaPoll(), does it have the exact same functionality? What libraries would I have to link to in order to use it? Can I increase the socket number safely in windows with FD_SETSIZE? My end program will be on a linux server. However I am testing on a windows system right now. Should I just swap my test machine over to a linux box? (probably going to anyway) Otherwise what would you recommend to use with windows? (sorry for all of the questions, I am doing research on my own, I promise =D)

    Read the article

< Previous Page | 30 31 32 33 34 35 36 37 38 39 40 41  | Next Page >