From 09a0f940df7fdb4ece34604e85693709df5c213e Mon Sep 17 00:00:00 2001
From: Alex Potsides <alex@achingbrain.net>
Date: Sat, 18 Dec 2021 07:34:27 +0100
Subject: [PATCH] fix: increase the maxlisteners for timeout controllers
 (#1065)

We use timeout controllers to ensure we're not dialling peers forever but we can end up registering lots of listeners for the `abort` event when peers have a lot of addresses.

In node this means we see an unhelpful `MaxListenersExceededWarning` in the console warning of a potential memory leak.

Increase the max number of listeners on the signal to silence the warning.
---
 src/dialer/index.js | 7 ++++++-
 src/peer-routing.js | 9 ++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/dialer/index.js b/src/dialer/index.js
index 555d26f2..aed012c0 100644
--- a/src/dialer/index.js
+++ b/src/dialer/index.js
@@ -9,7 +9,8 @@ const { Multiaddr } = require('multiaddr')
 const { TimeoutController } = require('timeout-abort-controller')
 const { AbortError } = require('abortable-iterator')
 const { anySignal } = require('any-signal')
-
+// @ts-expect-error setMaxListeners is missing from the types
+const { setMaxListeners } = require('events')
 const DialRequest = require('./dial-request')
 const { publicAddressesFirst } = require('libp2p-utils/src/address-sort')
 const getPeer = require('../get-peer')
@@ -253,6 +254,10 @@ class Dialer {
 
     // Combine the timeout signal and options.signal, if provided
     const timeoutController = new TimeoutController(this.timeout)
+    // this controller will potentially be used while dialing lots of
+    // peers so prevent MaxListenersExceededWarning appearing in the console
+    setMaxListeners && setMaxListeners(Infinity, timeoutController.signal)
+
     const signals = [timeoutController.signal]
     options.signal && signals.push(options.signal)
     const signal = anySignal(signals)
diff --git a/src/peer-routing.js b/src/peer-routing.js
index 8225a5a0..fd6f9920 100644
--- a/src/peer-routing.js
+++ b/src/peer-routing.js
@@ -24,6 +24,8 @@ const {
 // @ts-ignore module with no types
 } = require('set-delayed-interval')
 const { DHTPeerRouting } = require('./dht/dht-peer-routing')
+// @ts-expect-error setMaxListeners is missing from the types
+const { setMaxListeners } = require('events')
 
 /**
  * @typedef {import('peer-id')} PeerId
@@ -149,7 +151,12 @@ class PeerRouting {
     }
 
     if (options.timeout) {
-      options.signal = new TimeoutController(options.timeout).signal
+      const controller = new TimeoutController(options.timeout)
+      // this controller will potentially be used while dialing lots of
+      // peers so prevent MaxListenersExceededWarning appearing in the console
+      setMaxListeners && setMaxListeners(Infinity, controller.signal)
+
+      options.signal = controller.signal
     }
 
     yield * pipe(