From dec3791f4c693132cf9252884359ea212fdd50cf Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Tue, 6 Dec 2022 14:04:10 -0800
Subject: [PATCH 1/2] Log a warning if task queues exceed deadline by 20ms

Fixes #4292
---
 src/common/TaskQueue.ts | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/common/TaskQueue.ts b/src/common/TaskQueue.ts
index 94c5c53b3b..4674ad5b53 100644
--- a/src/common/TaskQueue.ts
+++ b/src/common/TaskQueue.ts
@@ -66,6 +66,8 @@ abstract class TaskQueue implements ITaskQueue {
     this._idleCallback = undefined;
     let taskDuration = 0;
     let longestTask = 0;
+    let lastDeadlineRemaining = deadline.timeRemaining();
+    let deadlineRemaining = 0;
     while (this._i < this._tasks.length) {
       taskDuration = performance.now();
       this._tasks[this._i++]();
@@ -73,10 +75,17 @@ abstract class TaskQueue implements ITaskQueue {
       longestTask = Math.max(taskDuration, longestTask);
       // Guess the following task will take a similar time to the longest task in this batch, allow
       // additional room to try avoid exceeding the deadline
-      if (longestTask * 1.5 > deadline.timeRemaining()) {
+      deadlineRemaining = deadline.timeRemaining();
+      if (longestTask * 1.5 > deadlineRemaining) {
+        // Warn when the time exceeding the deadline is over 20ms, if this happens in practice the
+        // task should be split into sub-tasks to ensure the UI remains responsive.
+        if (lastDeadlineRemaining - taskDuration < -5) {
+          console.warn(`task queue exceeded allotted deadline by ${Math.abs(Math.round(lastDeadlineRemaining - taskDuration))}ms`, { stacktrace: new Error().stack });
+        }
         this._start();
         return;
       }
+      lastDeadlineRemaining = deadlineRemaining;
     }
     this.clear();
   }

From 650cda31fd265a1798778787a426381c84098b2d Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Tue, 6 Dec 2022 14:10:40 -0800
Subject: [PATCH 2/2] Tweak logging

---
 src/common/TaskQueue.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/common/TaskQueue.ts b/src/common/TaskQueue.ts
index 4674ad5b53..30068a5f9a 100644
--- a/src/common/TaskQueue.ts
+++ b/src/common/TaskQueue.ts
@@ -79,8 +79,8 @@ abstract class TaskQueue implements ITaskQueue {
       if (longestTask * 1.5 > deadlineRemaining) {
         // Warn when the time exceeding the deadline is over 20ms, if this happens in practice the
         // task should be split into sub-tasks to ensure the UI remains responsive.
-        if (lastDeadlineRemaining - taskDuration < -5) {
-          console.warn(`task queue exceeded allotted deadline by ${Math.abs(Math.round(lastDeadlineRemaining - taskDuration))}ms`, { stacktrace: new Error().stack });
+        if (lastDeadlineRemaining - taskDuration < -20) {
+          console.warn(`task queue exceeded allotted deadline by ${Math.abs(Math.round(lastDeadlineRemaining - taskDuration))}ms`);
         }
         this._start();
         return;