CODEWITHSUNDEEP
javascriptnode.jsarrayslistmultiprocessing
DUMBUSER
DUMBUSER

Reputation: 531

How do I make each worker use the first element of an list in Node.JS?

I am using cluster (node js ) and I want every worker use the first element of an array, I want to use this method because I don't want to use a for loop

Multi_processing = (() => {
  let name;
  x = [1,2,3,4]
  return async() => {
    
    if (cluster.isMaster) {
      
      // name = await prompt(' input ');// input which I want to be reused in else 
      console.log(`Master ${process.pid} is running`);
      for (let i = 0; i <2; i++) {
        cluster.fork();
        
      }
      cluster.on('exit', (worker, code, signal) => {
        console.log(`worker ${worker.process.pid} finished`);
      });
    } else {
      console.log(x.shift()) // name is undefined
      console.log(`Worker ${process.pid} started`);
      console.log(x)
    }
  };
})();

Multi_processing();

So I did it in that way so the first worker that start use the first element then delete it and so on.

Upvotes: 0

Views: 143

Answers (1)

Thomas Sablik
Thomas Sablik

Reputation: 16449

You are creating separate processes with separate memory. The array is copied into each process. The easiest way to achieve what you want is to pass the values to each process:

const cluster = require('cluster');

Multi_processing = (() => {
    return async () => {

        if (cluster.isMaster) {
            x = [1, 2, 3, 4];
            console.log(`Master ${process.pid} is running`);
            for (let i = 0; i < 2; i++) {
                cluster.fork({ x: x[i] });

            }
            cluster.on('exit', (worker, code, signal) => {
                console.log(`worker ${worker.process.pid} finished`);
            });
        } else {
            console.log(`Worker ${process.pid} started`);
            console.log(process.env.x);
        }
    };
})();

Multi_processing();

Another way is implement inter-process communication (IPC) and let the workers and master communicate. Here you can find more about IPC in Node.js.

Upvotes: 2

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