text: // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  
  
  
  var common = require('../common');
  var assert = require('assert');
  var Buffer = require('buffer').Buffer;
  var dgram = require('dgram');
  
  var debug = false;
  var tests_run = 0;
  
  function pingPongTest(port, host) {
    var callbacks = 0;
    var N = 500;
    var count = 0;
    var sent_final_ping = false;
  
    var server = dgram.createSocket('udp4', function(msg, rinfo) {
      if (debug) console.log('server got: ' + msg +
                             ' from ' + rinfo.address + ':' + rinfo.port);
  
      if (/PING/.exec(msg)) {
        var buf = new Buffer(4);
        buf.write('PONG');
        server.send(buf, 0, buf.length,
                    rinfo.port, rinfo.address,
                    function(err, sent) {
                      callbacks++;
                    });
      }
    });
  
    server.on('error', function(e) {
      throw e;
    });
  
    server.on('listening', function() {
      console.log('server listening on ' + port + ' ' + host);
  
      var buf = new Buffer('PING'),
          client = dgram.createSocket('udp4');
  
      client.on('message', function(msg, rinfo) {
        if (debug) console.log('client got: ' + msg +
                               ' from ' + rinfo.address + ':' + rinfo.port);
        assert.equal('PONG', msg.toString('ascii'));
  
        count += 1;
  
        if (count < N) {
          client.send(buf, 0, buf.length, port, 'localhost');
        } else {
          sent_final_ping = true;
          client.send(buf, 0, buf.length, port, 'localhost', function() {
            client.close();
          });
        }
      });
  
      client.on('close', function() {
        console.log('client has closed, closing server');
        assert.equal(N, count);
        tests_run += 1;
        server.close();
        assert.equal(N - 1, callbacks);
      });
  
      client.on('error', function(e) {
        throw e;
      });
  
      console.log('Client sending to ' + port + ', localhost ' + buf);
      client.send(buf, 0, buf.length, port, 'localhost', function(err, bytes) {
        if (err) {
          throw err;
        }
        console.log('Client sent ' + bytes + ' bytes');
      });
      count += 1;
    });
    server.bind(port, host);
  }
  
  // All are run at once, so run on different ports
  pingPongTest(20989, 'localhost');
  pingPongTest(20990, 'localhost');
  pingPongTest(20988);
  //pingPongTest('/tmp/pingpong.sock');
  
  process.on('exit', function() {
    assert.equal(3, tests_run);
    console.log('done');
  });
  