fork-list

Fork List

It's easy to fork a list of child process for node.js by ForkList.

Install

npm install fork-list

Quick Examples

var ForkList = require('fork-list');

// which script to run by multiprocess
var path = './script/write';

// child process num
var num = 3;

var forks = new ForkList({
    path: path,
    num: num
});

for (var i = 0; i < 10; i++) {
    forks.send('hello~', i);
}

forks.shutdown();

the ./script/write.js is:

var Forks = require('fork-list');

Forks.proc(function(data1, data2) {
    console.log('Work id:', this.workid, 'recv data1:', data1, 'data2:', data2);
});

Output:

Work id: 1 recv data1: hello~ data2: 1
Work id: 2 recv data1: hello~ data2: 0
Work id: 0 recv data1: hello~ data2: 5
Work id: 1 recv data1: hello~ data2: 2
Work id: 2 recv data1: hello~ data2: 3
Work id: 1 recv data1: hello~ data2: 9
Work id: 2 recv data1: hello~ data2: 4
Work id: 0 recv data1: hello~ data2: 6
Work id: 2 recv data1: hello~ data2: 7
Work id: 2 recv data1: hello~ data2: 8

Documentation

Initialization

• new
• count
• setClassifier
• setLogger

Transfer

• send
• forward
• proc

Control

• kill
• killByPid
• shutdown

Event

• onExit
• onError
• onFinish

## Initialization ### new(path)

fork a new process with specify path.

### count()

get total number of processes.

### setClassifier(classifier)

set special classifier.

### setLogger(logger)

enable or disable fork-list debug log, or set your special logger such as log4js.getLogger.

Example

var ForkList = require('fork-list');
var underscore = require('underscore');

var times = 10;
var forks = new ForkList();

forks.new('./script');
forks.new('./script');

forks.setClassifier(function(msg, done) {
    var id = underscore.random(0, forks.count() - 1);
    done(null, id);
});

for (var i = 0; i < times; i++) {
    forks.send(i, 'some msg');
}

forks.shutdown();

## Transfor ### send(msg, ..., cb) Master: transfor usual data.

var forkList = require('fork-list');

// which script to run by multiprocess
var path = './test';

// child process num
var num = 2;

var forks = new ForkList({
    path: path,
    num: num
});

// send data to child process
forks.send(somedata, ...);

The usual data include:

• Number
• String
• Array
• JSON
• Object*

Caution The Object data wouldn't complete delivery:

var forks = new ForkList({
    path: path
});

function test(name) {
    this.name = name || 'default';
}

test.prototype.hi = function() {
    console.log('my name is ', this.name);
};

for (var i = 0; i < times; i++) {
    var t = new test('Alan' + i);
    forks.send(i, t);
}

you can only get the basic data { name: 'AlanX' }, and the prototype will lost, you can't call .hi in the child process.

### forward(type, handleObject, ..., cb) Master: transfor `Handle object`, include server object and socket object.

Socket forward exmaple

server.js

var net = require('net');
var config = require('./my_config');
var ForkList = require("fork-list");

var num = 2;
var path = './worker';

var wokers = new ForkList({
    path: path,
    num: num
});

var server = net.createServer();

server.on('connection', function(sock) {

    wokers.foward('socket', sock);

    sock.on('error', function(e) {
        console.log('[server] Error:', e);
    });
});

server.listen(config.port);

console.log('test socket server start');

worker.js

var ForkList = require('fork-list');

ForkList.proc(function(sock) {
    var workid = this.workid;
    sock.on('data', function(data) {
        console.log('[worker] id:', workid, 'data:', data.toString());
    })
});

test client.js

var config = require('./my_config');
var net = require('net');

var client = net.connect({
    hostname: config.host,
    port: config.port
});

client.on('connect', function() {
    var str = 'hello ';
    for (var i = 0; i < 100; i++) {
        client.write(str + i + ' ');
    }
    client.end();
});

client.on('end', function() {
    console.log('client send over!');
});

### proc(cb) Subprocess: get data from master.

var forkList = require('fork-list');

forkList.proc(function(msg, ...) {
    /* code */
});

## Control ### kill(workid)

This will forcely kill special child process, and don't care if there are some jobs haven't done.

### killByPid(pid)

This will forcely kill special child process, and don't care if there are some jobs haven't done.

### shutdown()

This will forcely shutdown all child process, and don't care if there are some jobs haven't done. and once all of child process has exited, the finish event will emit.

## Event ### onExit ### onError ### onFinish

Example:

var ForkList = require('fork-list');

var path = './script';
var num = 3;

var forks = new ForkList({
    path: path,
    num: num,
    log: true
});

for (var i = 10; i >= 0; i--) {
    forks.send('hello ' + i);
};

forks.on('error', function(err, pid) {
    console.log('--> Error:', err.message, 'pid:', pid);
});

forks.on('exit', function(pid) {
    console.log('--> Child process exit, pid:', pid);
    forks.killByPid(pid);
});

forks.on('finish', function() {
    console.log('--> All of child process has exited');
});

forks.shutdown();

script.js

var Forks = require('fork-list');

Forks.proc(function(data1, data2) {
    console.log('Work id:', this.workid, 'recv data1:', data1);
});

Output:

Work id: 0 recv data1: hello 10
Work id: 0 recv data1: hello 8
Work id: 0 recv data1: hello 7
Work id: 2 recv data1: hello 9
Work id: 0 recv data1: hello 6
Work id: 1 recv data1: hello 5
Work id: 0 recv data1: hello 2
Work id: 0 recv data1: hello 0
Work id: 1 recv data1: hello 4
Work id: 1 recv data1: hello 3
Work id: 1 recv data1: hello 1
--> Child process exit, pid: 15064
--> Error: IPC channel is already disconnected pid: 15064
--> Child process exit, pid: 13072
--> Error: IPC channel is already disconnected pid: 13072
--> Child process exit, pid: 4900
--> Error: IPC channel is already disconnected pid: 4900
--> All of child process has exited

Test

you can test this module by:

cd node_modules/fork-list
npm test

license

MIT