MULTICPU

Distributes the processing of a list of items over all available CPUs.

Installation

1/ install the package:

npm install --save-dep multicpu

2/ Have a look at the example app.js

``javascript
const multicpu = require("multicpu");

/**
* build and return a list of items, to be sent to each worker
* @param {int} cpu number of CPU to be used
* @returns {array} array of items, which will be sent one by one to the workers
*/
function start(cpu) {
console.log("#CPU ", cpu);

// build an array of N entries.
let arr = [];
for (let i = 2; i < 20; i++)
arr.push({
wait:i,
detail:will wait for ${i} seconds
});
return arr;
}

/**
* process an item from the list built by start, spread over workers running on all CPUs. n this example, wait for the numer of seconds provided in parameters
* @async
* @param {object} item one item of the list provided by start
*/
async function processing(item) {
console.log(${process.pid} processing, item);

let p = new Promise((resolve) => {
setTimeout(() => {
console.log(has waited ${item.wait} seconds);
resolve();
}, item.wait * 1000);

});
await p;
return item.wait
}


/**
* called at the end of whole processing for master to do whatever work
* @param {Object} list - list of {req,res,pid}
* @param {Object} list.req - item from request
* @param {Object} list.res - result from processing
* @param {Object} list.pid - pid which did the processing
*/
function end(list) {
console.log("end is called with this list",list);

var dt = new Date();
console.log(dt.toString());
}

multicpu.start({
start: start,
process: processing,
end: end
});
``

*

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