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 cluster = require('cluster');
  var net = require('net');
  
  function forEach(obj, fn) {
    Object.keys(obj).forEach(function(name, index) {
      fn(obj[name], name, index);
    });
  }
  
  if (cluster.isWorker) {
    // Create a tcp server. This will be used as cluster-shared-server and as an
    // alternative IPC channel.
    var server = net.Server();
    var socket, message;
  
    function maybeReply() {
      if (!socket || !message) return;
  
      // Tell master using TCP socket that a message is received.
      socket.write(JSON.stringify({
        code: 'received message',
        echo: message
      }));
    }
  
    server.on('connection', function(socket_) {
      socket = socket_;
      maybeReply();
  
      // Send a message back over the IPC channel.
      process.send('message from worker');
    });
  
    process.on('message', function(message_) {
      message = message_;
      maybeReply();
    });
  
    server.listen(common.PORT, '127.0.0.1');
  }
  
  else if (cluster.isMaster) {
  
    var checks = {
      master: {
        'receive': false,
        'correct': false
      },
      worker: {
        'receive': false,
        'correct': false
      }
    };
  
  
    var client;
    var check = function(type, result) {
      checks[type].receive = true;
      checks[type].correct = result;
      console.error('check', checks);
  
      var missing = false;
      forEach(checks, function(type) {
        if (type.receive === false) missing = true;
      });
  
      if (missing === false) {
        console.error('end client');
        client.end();
      }
    };
  
    // Spawn worker
    var worker = cluster.fork();
  
    // When a IPC message is resicved form the worker
    worker.on('message', function(message) {
      check('master', message === 'message from worker');
    });
  
    // When a TCP connection is made with the worker connect to it
    worker.on('listening', function() {
  
      client = net.connect(common.PORT, function() {
        // Send message to worker.
        worker.send('message from master');
      });
  
      client.on('data', function(data) {
        // All data is JSON
        data = JSON.parse(data.toString());
  
        if (data.code === 'received message') {
          check('worker', data.echo === 'message from master');
        } else {
          throw new Error('wrong TCP message recived: ' + data);
        }
      });
  
      // When the connection ends kill worker and shutdown process
      client.on('end', function() {
        worker.destroy();
      });
  
      worker.on('exit', function() {
        process.exit(0);
      });
    });
  
    process.once('exit', function() {
      forEach(checks, function(check, type) {
        assert.ok(check.receive, 'The ' + type + ' did not receive any message');
        assert.ok(check.correct,
                  'The ' + type + ' did not get the correct message');
      });
    });
  }
  