nevir / node-sync-ipc

node.js library for synchronous communication between main process and forked child processes.

node-sync-ipc

node-sync-ipc is a tiny library making it possible for child node.js processes created by child_process.fork to send synchronous message to parent process. It can block the child process until the parent make a response. This use case is kind of rare but I hope it can be of some help if anyone needs.

Install

npm install node-sync-ipc

Usage

In parent process:

// parent.js

var syncIpc = require("node-sync-ipc").parent();

// fork the child process just like child_process.fork()
var child = syncIpc.fork("./child-cal-sum.js");

// or add an existing process instance forked from this process
// syncIpc.addChild(child);

child.onSync("foo",function(res,bar){

    bar = bar + " " +bar;
    // block the child process for one second
    setTimeout(function(){
        // the first argument will be passed to child process as the result
        res(bar);
    },1000)
});

In child process:

// child-cal-sum.js

var syncIpc = require("node-sync-ipc").child();

// will log "echo content echo content" in console

console.log(syncIpc.sendSync("foo","echo content"));

Attention

Data should be serializable

Data to be transferred will be serialized and deserialized in the format of JSON. Error will be thrown if data is not serializable by JSON.stringify.

Also class information will be lost during the communication.

Sock file

On Unix based system, this module would create a nodePipe${parentPid}.sock in the home directory (or defined by the HOME environment variable). In most cases this file would be deleted correctly. But currently it is not guaranteed if process was killed unexpectedly.

Electron && NW.js

This module has c++ add-ons, so you have to rebuild it to use it in Electron.

Copyright

Copyright (c) 2017 Hang Ma. See LICENSE for details.