Created
June 21, 2019 15:18
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const cluster = require('cluster'); | |
async function waitForMessage(child) { | |
return new Promise(resolve => { | |
child.once('message', msg => { | |
console.log('Master. waitForMessage. Message is received', msg); | |
return resolve(); | |
}); | |
}); | |
} | |
if (cluster.isMaster) { | |
console.log(`Master ${process.pid} is running`); | |
const child = cluster.fork(); | |
child.once('exit', (worker, code, signal) => { | |
console.log(`worker ${worker.process.pid} died`); | |
}); | |
child.on('message', msg => { | |
console.log(`Master. Message observer: ${msg}`); | |
}); | |
child.once('online', async () => { | |
console.log('Master. Sending command.'); | |
child.send('start'); | |
console.log('Master. Start of await #1.'); | |
await waitForMessage(child); | |
console.log('Master. End of await #1.'); | |
console.log('Master. Start of await #2.'); | |
await waitForMessage(child); | |
console.log('Master. End of await #2.'); | |
process.exit(0); | |
}); | |
} else { | |
console.log(`Worker ${process.pid} started`); | |
process.on('message', (msg) => { | |
if (msg !== 'start') return; | |
process.send('message1'); | |
process.send('message2'); | |
process.send('message3'); | |
}); | |
} | |
/* | |
Master 11853 is running | |
Master. Sending command. | |
Master. Start of await #1. | |
Worker 11854 started | |
Master. Message observer: message1 | |
Master. waitForMessage. Message is received message1 | |
Master. Message observer: message2 | |
Master. Message observer: message3 | |
Master. End of await #1. | |
Master. Start of await #2. | |
// hanged up | |
-------- | |
Master 11860 is running | |
Master. Sending command. | |
Master. Start of await #1. | |
Worker 11861 started | |
Master. Message observer: message1 | |
Master. waitForMessage. Message is received message1 | |
Master. End of await #1. | |
Master. Start of await #2. | |
Master. Message observer: message2 | |
Master. waitForMessage. Message is received message2 | |
Master. Message observer: message3 | |
Master. End of await #2. | |
Process finished with exit code 0 | |
// executed ok | |
*/ |
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