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test: eliminate multicast test FreeBSD flakiness
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test-dgram-multicast-multi-process was flaky on FreeBSD and Raspeberry
Pi. This refactoring fixes the issue by eliminating a race condition.

Fixes: nodejs#2474
PR-URL: nodejs#4042
Reviewed-By: Ben Noordhuis <[email protected]>
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@Trott
Trott committed Dec 1, 2015
1 parent 82b8355 commit b3313aa
Showing 1 changed file with 150 additions and 151 deletions.
301 changes: 150 additions & 151 deletions test/internet/test-dgram-multicast-multi-process.js
View file
Original file line number Diff line number Diff line change
@@ -1,30 +1,122 @@
'use strict';
var common = require('../common'),
assert = require('assert'),
dgram = require('dgram'),
util = require('util'),
Buffer = require('buffer').Buffer,
fork = require('child_process').fork,
LOCAL_BROADCAST_HOST = '224.0.0.114',
TIMEOUT = common.platformTimeout(5000),
messages = [
new Buffer('First message to send'),
new Buffer('Second message to send'),
new Buffer('Third message to send'),
new Buffer('Fourth message to send')
];
const common = require('../common');
const assert = require('assert');
const dgram = require('dgram');
const fork = require('child_process').fork;
const LOCAL_BROADCAST_HOST = '224.0.0.114';
const TIMEOUT = common.platformTimeout(5000);
const messages = [
new Buffer('First message to send'),
new Buffer('Second message to send'),
new Buffer('Third message to send'),
new Buffer('Fourth message to send')
];
const workers = {};
const listeners = 3;


// Skip test in FreeBSD jails.
if (common.inFreeBSDJail) {
console.log('1..0 # Skipped: In a FreeBSD jail');
return;
}

function launchChildProcess(index) {
const worker = fork(__filename, ['child']);
workers[worker.pid] = worker;

worker.messagesReceived = [];

// Handle the death of workers.
worker.on('exit', function(code, signal) {
// Don't consider this the true death if the worker has finished
// successfully or if the exit code is 0.
if (worker.isDone || code === 0) {
return;
}

dead += 1;
console.error('[PARENT] Worker %d died. %d dead of %d',
worker.pid,
dead,
listeners);

if (dead === listeners) {
console.error('[PARENT] All workers have died.');
console.error('[PARENT] Fail');
process.exit(1);
}
});

worker.on('message', function(msg) {
if (msg.listening) {
listening += 1;

if (listening === listeners) {
// All child process are listening, so start sending.
sendSocket.sendNext();
}
return;
}
if (msg.message) {
worker.messagesReceived.push(msg.message);

if (worker.messagesReceived.length === messages.length) {
done += 1;
worker.isDone = true;
console.error('[PARENT] %d received %d messages total.',
worker.pid,
worker.messagesReceived.length);
}

if (done === listeners) {
console.error('[PARENT] All workers have received the ' +
'required number of messages. Will now compare.');

Object.keys(workers).forEach(function(pid) {
const worker = workers[pid];

var count = 0;

worker.messagesReceived.forEach(function(buf) {
for (var i = 0; i < messages.length; ++i) {
if (buf.toString() === messages[i].toString()) {
count++;
break;
}
}
});

console.error('[PARENT] %d received %d matching messages.',
worker.pid, count);

assert.strictEqual(count, messages.length,
'A worker received an invalid multicast message');
});

clearTimeout(timer);
console.error('[PARENT] Success');
killChildren(workers);
}
}
});
}

function killChildren(children) {
Object.keys(children).forEach(function(key) {
const child = children[key];
child.kill();
});
}

if (process.argv[2] !== 'child') {
var workers = {},
listeners = 3,
listening = 0,
dead = 0,
i = 0,
done = 0,
timer = null;

//exit the test if it doesn't succeed within TIMEOUT
timer = setTimeout(function() {
var listening = 0;
var dead = 0;
var i = 0;
var done = 0;

// Exit the test if it doesn't succeed within TIMEOUT.
var timer = setTimeout(function() {
console.error('[PARENT] Responses were not received within %d ms.',
TIMEOUT);
console.error('[PARENT] Fail');
Expand All @@ -34,101 +126,18 @@ if (process.argv[2] !== 'child') {
process.exit(1);
}, TIMEOUT);

//launch child processes
// Launch child processes.
for (var x = 0; x < listeners; x++) {
(function() {
var worker = fork(process.argv[1], ['child']);
workers[worker.pid] = worker;

worker.messagesReceived = [];

//handle the death of workers
worker.on('exit', function(code, signal) {
// don't consider this the true death if the
// worker has finished successfully

// or if the exit code is 0
if (worker.isDone || code === 0) {
return;
}

dead += 1;
console.error('[PARENT] Worker %d died. %d dead of %d',
worker.pid,
dead,
listeners);

if (dead === listeners) {
console.error('[PARENT] All workers have died.');
console.error('[PARENT] Fail');

killChildren(workers);

process.exit(1);
}
});

worker.on('message', function(msg) {
if (msg.listening) {
listening += 1;

if (listening === listeners) {
//all child process are listening, so start sending
sendSocket.sendNext();
}
}
else if (msg.message) {
worker.messagesReceived.push(msg.message);

if (worker.messagesReceived.length === messages.length) {
done += 1;
worker.isDone = true;
console.error('[PARENT] %d received %d messages total.',
worker.pid,
worker.messagesReceived.length);
}

if (done === listeners) {
console.error('[PARENT] All workers have received the ' +
'required number of messages. Will now compare.');

Object.keys(workers).forEach(function(pid) {
var worker = workers[pid];

var count = 0;

worker.messagesReceived.forEach(function(buf) {
for (var i = 0; i < messages.length; ++i) {
if (buf.toString() === messages[i].toString()) {
count++;
break;
}
}
});

console.error('[PARENT] %d received %d matching messages.',
worker.pid, count);

assert.equal(count, messages.length,
'A worker received an invalid multicast message');
});

clearTimeout(timer);
console.error('[PARENT] Success');
killChildren(workers);
}
}
});
})(x);
launchChildProcess(x);
}

var sendSocket = dgram.createSocket('udp4');
// FIXME a libuv limitation makes it necessary to bind()
// before calling any of the set*() functions - the bind()
// call is what creates the actual socket...
// FIXME: a libuv limitation makes it necessary to bind()
// before calling any of the set*() functions. The bind()
// call is what creates the actual socket.
sendSocket.bind();

// The socket is actually created async now
// The socket is actually created async now.
sendSocket.on('listening', function() {
sendSocket.setTTL(1);
sendSocket.setBroadcast(true);
Expand All @@ -141,7 +150,7 @@ if (process.argv[2] !== 'child') {
});

sendSocket.sendNext = function() {
var buf = messages[i++];
const buf = messages[i++];

if (!buf) {
try { sendSocket.close(); } catch (e) {}
Expand All @@ -151,61 +160,51 @@ if (process.argv[2] !== 'child') {
sendSocket.send(buf, 0, buf.length,
common.PORT, LOCAL_BROADCAST_HOST, function(err) {
if (err) throw err;
console.error('[PARENT] sent %s to %s:%s',
util.inspect(buf.toString()),
console.error('[PARENT] sent "%s" to %s:%s',
buf.toString(),
LOCAL_BROADCAST_HOST, common.PORT);
process.nextTick(sendSocket.sendNext);
});
};

function killChildren(children) {
Object.keys(children).forEach(function(key) {
var child = children[key];
child.kill();
});
}
}

if (process.argv[2] === 'child') {
var receivedMessages = [];
var listenSocket = dgram.createSocket({
const receivedMessages = [];
const listenSocket = dgram.createSocket({
type: 'udp4',
reuseAddr: true
});

listenSocket.on('message', function(buf, rinfo) {
console.error('[CHILD] %s received %s from %j', process.pid,
util.inspect(buf.toString()), rinfo);
listenSocket.on('listening', function() {
listenSocket.addMembership(LOCAL_BROADCAST_HOST);

receivedMessages.push(buf);
listenSocket.on('message', function(buf, rinfo) {
console.error('[CHILD] %s received "%s" from %j', process.pid,
buf.toString(), rinfo);

process.send({ message: buf.toString() });
receivedMessages.push(buf);

if (receivedMessages.length == messages.length) {
// .dropMembership() not strictly needed but here as a sanity check
listenSocket.dropMembership(LOCAL_BROADCAST_HOST);
process.nextTick(function() {
listenSocket.close();
});
}
});
process.send({ message: buf.toString() });

listenSocket.on('close', function() {
//HACK: Wait to exit the process to ensure that the parent
//process has had time to receive all messages via process.send()
//This may be indicitave of some other issue.
setTimeout(function() {
process.exit();
}, 1000);
});
if (receivedMessages.length == messages.length) {
// .dropMembership() not strictly needed but here as a sanity check.
listenSocket.dropMembership(LOCAL_BROADCAST_HOST);
process.nextTick(function() {
listenSocket.close();
});
}
});

listenSocket.on('listening', function() {
listenSocket.on('close', function() {
// HACK: Wait to exit the process to ensure that the parent
// process has had time to receive all messages via process.send()
// This may be indicative of some other issue.
setTimeout(function() {
process.exit();
}, common.platformTimeout(1000));
});
process.send({ listening: true });
});

listenSocket.bind(common.PORT);

listenSocket.on('listening', function() {
listenSocket.addMembership(LOCAL_BROADCAST_HOST);
});
}

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