'use strict'; var common = require('../common'); var dgram = require('dgram'); var callbacks = 0; var client; var timer; if (common.isOSX) { common.skip('because of 17894467 Apple bug'); return; } client = dgram.createSocket('udp4'); client.bind(0, function() { function callback() { callbacks++; if (callbacks == 2) { clearTimeout(timer); client.close(); } else if (callbacks > 2) { throw new Error('the callbacks should be called only two times'); } } client.on('message', function(buffer, bytes) { callback(); }); const port = this.address().port; client.send( Buffer.allocUnsafe(1), 0, 0, port, '127.0.0.1', (err, len) => { callback(); }); timer = setTimeout(function() { throw new Error('Timeout'); }, 200); });