MaxListenersExceededWarning: Possible EventEmitter memory leak detected

[achingbrain]

After about 10 hours running I start seeing MaxListenersExceededWarning:

node:internal/process/warning:50 (node:81670) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 _device listeners added to [Ssdp]. Use emitter.setMaxListeners() to increase limit
    at _addListener (node:events:465:17)
    at Ssdp.addListener (node:events:487:10)
    at Ssdp.search (/Users/alex/Documents/Workspaces/ipfs/js-ipfs/node_modules/nat-api/lib/upnp/ssdp.js:84:10)
    at Client.findGateway (/Users/alex/Documents/Workspaces/ipfs/js-ipfs/node_modules/nat-api/lib/upnp/index.js:186:25)
    at Client.portMapping (/Users/alex/Documents/Workspaces/ipfs/js-ipfs/node_modules/nat-api/lib/upnp/index.js:23:10)
    at NatAPI._upnpMap (/Users/alex/Documents/Workspaces/ipfs/js-ipfs/node_modules/nat-api/index.js:315:22)
    at listOnTimeout (node:internal/timers:557:17)
    at processTimers (node:internal/timers:500:7)

[cascandaliato]

I believe the problem lies in this method:

nat-api/index.js

Line 312 in e404453

_upnpMap (opts, cb) {

Specifically, here:

nat-api/index.js

Lines 327 to 332 in e404453

	if (self.autoUpdate) {
	self._upnpIntervals[opts.publicPort + ':' + opts.privatePort + '-' + opts.protocol] = setInterval(
	self._upnpMap.bind(self, opts, () => {}),
	self._timeout
	)
	}

When autoupdate is enabled (default behavior), _upnpMap gets called at regular intervals and, each time it executes, it adds an additional timer. This means that, over time, you get more and more _upnpMap calls firing at the same time, until you reach a point where the underlying code registers too many listeners in a short amount of time.

Partially related: I feel like the same could happen if you map too many ports with the same TTL. You would have a spike in the number of listeners, except that in this case there is no leak because listeners are correctly unregistered.

@alxhotel, any chance you can have a look at my analysis? I'll be happy to create a PR.