Child Process

Introduced in 4.0.0

Stability: 2 - Stable

const ChildProcess = require('kado/lib/ChildProcess')

This library provides an enhanced interface to use Node.js core child_process module.

NOTE: This library is not to be confused with the core ChildProcess object which is used internally.

Class: ChildProcess extends EventEmitter

ChildProcess.constructor(options)

• options {object} options used to setup the child process
• Return {ChildProcess} new instance tied to the child process.

ChildProcess.setEnv(env)

• env {object} new environment parameters to merge in
• Return {ChildProcess} this instance

ChildProcess.getEnv()

• Return {object} currently compiled environment object to be passed to new calls to cp.fork()

ChildProcess.setPath(path)

• path {string} set the child path to this new path.
• Return {ChildProcess} this instance

Change the path of the child process after instantiation.

ChildProcess.send(message, sendHandler, options)

• message {mixed} data to send to the child
• sendHandler {Handle} special handle used to pass sockets to workers, see the core Node.js documentation
• options {object} available options keepOpen which is also use specially for sending sockets.
• Return {object} of results indexed by the child pid.

ChildProcess.kill(signal = 'SIGTERM')

• signal {string} signal to be sent to the child process for termination.
• Return {object} result of ChildProcess.onExit(signal)

ChildProcess.start()

• Return {Promise} resolved when all bound children have started.

ChildProcess.stop()

• Return {Promise} resolved when all bound children have stopped.

ChildProcess.setStatus(status)

• status {string} set the current status of the system.
• Return {ChildProcess} this instance

Change the state of the child process instance.

Internal Use

ChildProcess.onExit(signal = 'SIGKILL')

• Return {number} of processes killed by this method.

Internal Use

ChildProcess.registerExitHandler()

• Return {void}

Internal Use

ChildProcess.handleMessage(proc, message)

• proc {cp} instance of core child_process object returned from fork.
• message {string} incoming message from child
• Return {void}

Passes the messages upwards via the message event.

Internal Use

ChildProcess.respawnChild()

• Return {void}

If the child is closed, and respawns are enabled and the state of the class is started = true this will start a new child process in the previous processes place.

Internal Use

ChildProcess.addChild(proc)

• proc {cp} instance of core child_process object returned from fork.
• Return {cp} proc instance passed in

This method will take a newly forked process and wrap it to work properly with the ChildProcess internals.

Internal Use

ChildProcess.stopChild(proc)

• proc {cp} instance of core child_process object returned from fork.
• Return {Promise} resolved when the proc instance is stopped.

Internal Use