Aurelia, Electron: Possible EventEmitter memory leak detected - electron

Question

I'm building a system resource monitor as a project using electron and aurelia.
Main.js
var ramInfo = {};
var result = await si.mem()
ramInfo.total = parseInt(result.total / 1024 / 1024);
ramInfo.used = parseInt(result.used / 1024 / 1024);
ramInfo.percentUsed = parseInt((ramInfo.used / ramInfo.total) * 100);
ramInfo.percentAvailable = parseInt((ramInfo.percentUsed - 100) * -1);
event.sender.send('ram-reply', ramInfo);
})
Overview.js:
async attached () {
await this.getRamInfo();
this.startDataRefresh();
}
async getRamInfo () {
window.ipc.send('ram');
await window.ipc.on('ram-reply', (event, result) => {
this.system.ram = result;
//This line gets logged an additional time each time the setInterval function runs
console.log(this.system.ram);
this.ramData.series = [this.system.ram.percentAvailable, this.system.ram.percentUsed];
new Chartist.Pie('.ram-chart', this.ramData , this.options);
});
console.log("Break");
}
startDataRefresh() {
let scope = this;
setInterval(function() {
scope.getRamInfo();
}, 3000);
}
I am receiving the folowing error in my electron console:
MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 ram-reply listeners added to [EventEmitter]. Use emitter.setMaxListeners() to increase limit
I would only think that the getRamInfo() function would run once every three seconds, however, the console.log portion of the function is getting logged an additional time each time the function runs. I'm fairly certain this is where the issue lies, I'm just not sure why it is running multiple times per interval.
EDIT:
I've reached a partial solution in moving the setInterval function into main.js:
ipcMain.on('ram', async (event) => {
setInterval(async function() {
var ramInfo = {};
var result = await si.mem()
ramInfo.total = parseInt(result.total / 1024 / 1024);
ramInfo.used = parseInt(result.used / 1024 / 1024);
ramInfo.percentUsed = parseInt((ramInfo.used / ramInfo.total) * 100);
ramInfo.percentAvailable = parseInt((ramInfo.percentUsed - 100) * -1);
event.sender.send('ram-reply', ramInfo)
}, 3000);
})
It seems like each time the original setInterval called to ipcMain this created a new listener and each time every listener returned the results. I would like it to be dependant on the view that is open so controlling this via the view would be preferable.

Answer 1

Try this:
async getRamInfo () {
window.ipc.send('ram');
return new Promise(resolve => window.ipc.once('ram-reply', (event, result) => resolve(result));
}
async refresh() {
const ramInfo = await this.getRamInfo();
this.ramData.series = [this.system.ram.percentAvailable, this.system.ram.percentUsed];
new Chartist.Pie('.ram-chart', this.ramData , this.options);
// ...
}
startDataRefresh() {
if(!this.interval) {
this.interval = setInterval(() => this.refresh(), 3000);
}
}
stopDataRefresh() {
if(this.interval) {
clearInterval(this.interval);
delete this.interval;
}
}
main part - window.ipc.once('ram-reply' - use once for one-time event subscription