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.
  
  'use strict';
  const common = require('../common');
  const assert = require('assert');
  const cluster = require('cluster');
  const net = require('net');
  
  if (cluster.isMaster) {
    const worker1 = cluster.fork();
  
    worker1.on('message', common.mustCall(function(msg) {
      assert.strictEqual(msg, 'success');
      const worker2 = cluster.fork();
  
      worker2.on('message', common.mustCall(function(msg) {
        assert.strictEqual(msg, 'server2:EADDRINUSE');
        worker1.kill();
        worker2.kill();
      }));
    }));
  } else {
    const server1 = net.createServer(common.mustNotCall());
    const server2 = net.createServer(common.mustNotCall());
  
    server1.on('error', function(err) {
      // no errors expected
      process.send(`server1:${err.code}`);
    });
  
    server2.on('error', function(err) {
      // an error is expected on the second worker
      process.send(`server2:${err.code}`);
    });
  
    server1.listen({
      host: 'localhost',
      port: common.PORT,
      exclusive: false
    }, common.mustCall(function() {
      server2.listen({ port: common.PORT + 1, exclusive: true },
                     common.mustCall(function() {
                       // the first worker should succeed
                       process.send('success');
                     })
      );
    }));
  }
  