From 70ac3f6f64328088ce9d4225b1597636f4b6b856 Mon Sep 17 00:00:00 2001
From: Robert Nagy <ronagy@icloud.com>
Date: Wed, 1 Mar 2023 08:25:46 +0100
Subject: [PATCH] fix: fast timers and event loop lag

---
 lib/timers.js | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/lib/timers.js b/lib/timers.js
index 4f4fcea4413..5782217a0e0 100644
--- a/lib/timers.js
+++ b/lib/timers.js
@@ -13,13 +13,15 @@ function onTimeout () {
   while (idx < len) {
     const timer = fastTimers[idx]
 
-    if (timer.expires && fastNow >= timer.expires) {
-      timer.expires = 0
+    if (timer.state === 0) {
+      timer.state = fastNow + timer.delay
+    } else if (timer.state > 0 && fastNow >= timer.state) {
+      timer.state = -1
       timer.callback(timer.opaque)
     }
 
-    if (timer.expires === 0) {
-      timer.active = false
+    if (timer.state === -1) {
+      timer.state = -2
       if (idx !== len - 1) {
         fastTimers[idx] = fastTimers.pop()
       } else {
@@ -53,27 +55,29 @@ class Timeout {
     this.callback = callback
     this.delay = delay
     this.opaque = opaque
-    this.expires = 0
-    this.active = false
+
+    //  -2 not in timer list
+    //  -1 in timer list but inactive
+    //   0 in timer list waiting for time
+    // > 0 in timer list waiting for time to expire
+    this.state = -2
 
     this.refresh()
   }
 
   refresh () {
-    if (!this.active) {
-      this.active = true
+    if (this.state === -2) {
       fastTimers.push(this)
       if (!fastNowTimeout || fastTimers.length === 1) {
         refreshTimeout()
-        fastNow = Date.now()
       }
     }
 
-    this.expires = fastNow + this.delay
+    this.state = 0
   }
 
   clear () {
-    this.expires = 0
+    this.state = -1
   }
 }