Fixes: nodejs#17169 (test-http-exceptions)

test/parallel/test-http-exceptions.js

@@ -21,7 +21,10 @@
 
 'use strict';
 require('../common');
+const Countdown = require('../common/countdown');
 const http = require('http');
+const NUMBER_OF_EXCEPTIONS = 4;
+const countdown = new Countdown(NUMBER_OF_EXCEPTIONS, () => process.exit(0));
 
 const server = http.createServer(function(req, res) {
   intentionally_not_defined(); // eslint-disable-line no-undef
@@ -30,16 +33,15 @@ const server = http.createServer(function(req, res) {
   res.end();
 });
 
+
 server.listen(0, function() {
-  for (let i = 0; i < 4; i += 1) {
+  for (let i = 0; i < NUMBER_OF_EXCEPTIONS; i += 1) {
     http.get({ port: this.address().port, path: `/busy/${i}` });
   }
 });
 
-let exception_count = 0;
-
 process.on('uncaughtException', function(err) {
   console.log(`Caught an exception: ${err}`);
   if (err.name === 'AssertionError') throw err;
-  if (++exception_count === 4) process.exit(0);
+  countdown.dec();
 });