It is found that the signaling mechanism used for interprocess communication in Node.js is very similar to the event mechanism (see the code example below). Is there any reason behind this? Or a design pattern?

signal

child.kill('SIGUSR1');
 process.on('SIGUSR1', function () {
 console.log('Got a SIGUSR1 signal.');
 })

event

eventEmitter.emit('event')
 eventEmitter.on('event', function () {
 console.log('Trigger an event.');
 })