1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
|
// 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 assert = require('assert');
var fork = require('child_process').fork;
var net = require('net');
var EventEmitter = require('events').EventEmitter;
var util = require('util');
function isObject(o) {
return (typeof o === 'object' && o !== null);
}
function extendObject(origin, add) {
// Don't do anything if add isn't an object
if (!add) return origin;
var keys = Object.keys(add),
i = keys.length;
while (i--) {
origin[keys[i]] = add[keys[i]];
}
return origin;
}
var debug;
if (process.env.NODE_DEBUG && /cluster/.test(process.env.NODE_DEBUG)) {
debug = function(x) {
var prefix = process.pid + ',' +
(process.env.NODE_WORKER_ID ? 'Worker' : 'Master');
console.error(prefix, x);
};
} else {
debug = function() { };
}
// cluster object:
function cluster() {}
util.inherits(cluster, EventEmitter);
var cluster = module.exports = new cluster();
// Used in the master:
var masterStarted = false;
var ids = 0;
var serverHandlers = {};
// Used in the worker:
var serverLisenters = {};
var queryIds = 0;
var queryCallbacks = {};
// Define isWorker and isMaster
cluster.isWorker = 'NODE_UNIQUE_ID' in process.env;
cluster.isMaster = ! cluster.isWorker;
// The worker object is only used in a worker
cluster.worker = cluster.isWorker ? {} : null;
// The workers array is oly used in the naster
cluster.workers = cluster.isMaster ? {} : null;
// Settings object
var settings = cluster.settings = {};
// Simple function there call a function on each worker
function eachWorker(cb) {
// Go througe all workers
for (var id in cluster.workers) {
if (cluster.workers.hasOwnProperty(id)) {
cb(cluster.workers[id]);
}
}
}
cluster.setupMaster = function(options) {
// This can only be called from the master.
assert(cluster.isMaster);
// Don't allow this function to run more that once
if (masterStarted) return;
masterStarted = true;
// Get filename and arguments
options = options || {};
// Set settings object
settings = cluster.settings = {
exec: options.exec || process.argv[1],
args: options.args || process.argv.slice(2),
silent: options.silent || false
};
// Kill workers when a uncaught exception is received
process.on('uncaughtException', function(err) {
// Did the user install a listener? If so, it overrides this one.
if (process.listeners('uncaughtException').length > 1) return;
// Output the error stack, and create on if non exist
if (!(err instanceof Error)) {
err = new Error(err);
}
console.error(err.stack);
// quick destroy cluster
quickDestroyCluster();
// when done exit process with error code: 1
process.exit(1);
});
// emit setup event
cluster.emit('setup');
};
// Check if a message is internal only
var INTERNAL_PREFIX = 'NODE_CLUSTER_';
function isInternalMessage(message) {
return (isObject(message) &&
typeof message.cmd === 'string' &&
message.cmd.indexOf(INTERNAL_PREFIX) === 0);
}
// Modyfi message object to be internal
function internalMessage(inMessage) {
var outMessage = extendObject({}, inMessage);
// Add internal prefix to cmd
outMessage.cmd = INTERNAL_PREFIX + (outMessage.cmd || '');
return outMessage;
}
// Handle callback messges
function handleResponse(outMessage, outHandle, inMessage, inHandle, worker) {
// The message there will be send
var message = internalMessage(outMessage);
// callback id - will be undefined if not set
message._queryEcho = inMessage._requestEcho;
// Call callback if a query echo is received
if (inMessage._queryEcho) {
queryCallbacks[inMessage._queryEcho](inMessage.content, inHandle);
delete queryCallbacks[inMessage._queryEcho];
}
// Send if outWrap do contain something useful
if (!(outMessage === undefined && message._queryEcho === undefined)) {
sendInternalMessage(worker, message, outHandle);
}
}
// Handle messages from both master and workers
var messageHandingObject = {};
function handleMessage(inMessage, inHandle, worker) {
//Remove internal prefix
var message = extendObject({}, inMessage);
message.cmd = inMessage.cmd.substr(INTERNAL_PREFIX.length);
var respondUsed = false;
var respond = function(outMessage, outHandler) {
respondUsed = true;
handleResponse(outMessage, outHandler, inMessage, inHandle, worker);
};
// Run handler if it exist
if (messageHandingObject[message.cmd]) {
messageHandingObject[message.cmd](message, worker, respond);
}
// Send respond if it wasn't done
if (respondUsed === false) {
respond();
}
}
// Messages to the master will be handled using this methods
if (cluster.isMaster) {
// Handle online messages from workers
messageHandingObject.online = function(message, worker) {
worker.state = 'online';
debug('Worker ' + worker.process.pid + ' online');
worker.emit('online', worker);
cluster.emit('online', worker);
};
// Handle queryServer messages form workers
messageHandingObject.queryServer = function(message, worker, send) {
// This sequence of infomation is unique to the connection but not
// to the worker
var args = [message.address, message.port, message.addressType];
var key = args.join(':');
var handler;
if (serverHandlers.hasOwnProperty(key)) {
handler = serverHandlers[key];
} else {
handler = serverHandlers[key] = net._createServerHandle.apply(net, args);
}
// echo callback with the fd handler associated with it
send({}, handler);
};
// Handle listening messages from workers
messageHandingObject.listening = function(message, worker) {
worker.state = 'listening';
// Emit listining, now that we know the worker is listning
worker.emit('listening', worker, {
address: message.address,
port: message.port,
addressType: message.addressType
});
cluster.emit('listening', worker, {
address: message.address,
port: message.port,
addressType: message.addressType
});
};
// Handle suicide messages from workers
messageHandingObject.suicide = function(message, worker) {
worker.suicide = true;
};
}
// Messages to a worker will be handled using this methods
else if (cluster.isWorker) {
// TODO: the disconnect step will use this
}
function toDecInt(value) {
value = parseInt(value, 10);
return isNaN(value) ? null : value;
}
// Create a worker object, there works both for master and worker
function Worker(customEnv) {
if (!(this instanceof Worker)) return new Worker();
var self = this;
var env = process.env;
// Assign uniqueID, default null
this.uniqueID = cluster.isMaster ? ++ids : toDecInt(env.NODE_UNIQUE_ID);
// Assign state
this.state = 'none';
// Create or get process
if (cluster.isMaster) {
// Create env object
// first: copy and add uniqueID
var envCopy = extendObject({}, env);
envCopy['NODE_UNIQUE_ID'] = this.uniqueID;
// second: extend envCopy with the env argument
if (isObject(customEnv)) {
envCopy = extendObject(envCopy, customEnv);
}
// fork worker
this.process = fork(settings.exec, settings.args, {
'env': envCopy,
'silent': settings.silent
});
} else {
this.process = process;
}
if (cluster.isMaster) {
// Save worker in the cluster.workers array
cluster.workers[this.uniqueID] = this;
// Emit a fork event, on next tick
// There is no worker.fork event since this has no real purpose
process.nextTick(function() {
cluster.emit('fork', self);
});
}
// Internal message: handle message
this.process.on('internalMessage', function(message, handle) {
debug('recived: ', message);
// relay to handleMessage
handleMessage(message, handle, self);
return;
});
// Non-internal message: relay to Worker object
this.process.on('message', function(message, handle) {
self.emit('message', message, handle);
});
// Handle exit
self.process.on('exit', function() {
debug('worker id=' + self.uniqueID + ' died');
// Prepare worker to die and emit events
prepareDeath(self, 'dead', 'death');
});
}
util.inherits(Worker, EventEmitter);
cluster.Worker = Worker;
function prepareDeath(worker, state, eventName) {
// set state to disconnect
worker.state = state;
// Make suicide a boolean
worker.suicide = !!worker.suicide;
// Remove from workers in the master
if (cluster.isMaster) {
delete cluster.workers[worker.uniqueID];
}
// Emit events
worker.emit(eventName, worker);
cluster.emit(eventName, worker);
}
// Send internal message
function sendInternalMessage(worker, message/*, handler, callback*/) {
// Exist callback
var callback = arguments[arguments.length - 1];
if (typeof callback !== 'function') {
callback = undefined;
}
// exist handler
var handler = arguments[2] !== callback ? arguments[2] : undefined;
if (!isInternalMessage(message)) {
message = internalMessage(message);
}
// Store callback for later
if (callback) {
message._requestEcho = worker.uniqueID + ':' + (++queryIds);
queryCallbacks[message._requestEcho] = callback;
}
worker.send(message, handler);
}
// Send message to worker or master
Worker.prototype.send = function() {
//You could also just use process.send in a worker
this.process.send.apply(this.process, arguments);
};
function closeWorkerChannel(worker, callback) {
//Apparently the .close method is async, but do not have a callback
worker.process._channel.close();
worker.process._channel = null;
process.nextTick(callback);
}
// Kill the worker without restarting
Worker.prototype.destroy = function() {
var self = this;
this.suicide = true;
if (cluster.isMaster) {
// Stop channel
// this way the worker won't need to propagate suicide state to master
closeWorkerChannel(this, function() {
// Then kill worker
self.process.kill();
});
} else {
// Channel is open
if (this.process._channel !== null) {
// Inform master that is is suicide and then kill
sendInternalMessage(this, {cmd: 'suicide'}, function() {
// Kill worker
process.exit(0);
});
// When master do a quickDestroy the channel is not necesarily closed
// at the point this function runs. For that reason we need to keep
// checking that the channel is still open, until a actually callback
// from the master is resicved. Also we can't do a timeout and then
// just kill, since we don't know if the quickDestroy function was called.
setInterval(function() {
if (self.process._channel === null) {
process.exit(0);
}
}, 200);
} else {
process.exit(0);
}
}
};
// Fork a new worker
cluster.fork = function(env) {
// This can only be called from the master.
assert(cluster.isMaster);
// Make sure that the master has been initalized
cluster.setupMaster();
return (new cluster.Worker(env));
};
// Sync way to quickly kill all cluster workers
// However the workers may not die instantly
function quickDestroyCluster() {
eachWorker(function(worker) {
worker.process.kill();
});
}
// Internal function. Called from src/node.js when worker process starts.
cluster._setupWorker = function() {
// Get worker class
var worker = cluster.worker = new Worker();
// Tell master that the worker is online
worker.state = 'online';
sendInternalMessage(worker, { cmd: 'online' });
};
// Internal function. Called by lib/net.js when attempting to bind a server.
cluster._getServer = function(tcpSelf, address, port, addressType, cb) {
// This can only be called from a worker.
assert(cluster.isWorker);
// Store tcp instance for later use
var key = [address, port, addressType].join(':');
serverLisenters[key] = tcpSelf;
// Send a listening message to the master
tcpSelf.once('listening', function() {
cluster.worker.state = 'listening';
sendInternalMessage(cluster.worker, {
cmd: 'listening',
address: address,
port: port,
addressType: addressType
});
});
// Request the fd handler from the master process
var message = {
cmd: 'queryServer',
address: address,
port: port,
addressType: addressType
};
// The callback will be stored until the master has responed
sendInternalMessage(cluster.worker, message, function(msg, handle) {
cb(handle);
});
};
|