From 8526770e9f0a3dcfe7d08077b21e6a786b964e80 Mon Sep 17 00:00:00 2001
From: Karl Seguin <k@openmymind.io>
Date: Sat, 21 Mar 2026 11:38:16 +0800
Subject: [PATCH] More aggressive timer cleanup

When a timer is cleared, e.g. clearInterval, we flag the task are deleted and
maintain the entry in window._timers. When run, the task is ignored and deleted
from _timers.

This can result in prematurely rejecting timers due to `TooManyTimeout`. One
pattern I've seen is a RAF associated with an element where the RAF is cleared
(cancelAnimationFrame) if already registered. This can quickly result in
TooManyTimers.

This commit removes the timer from _timers as soon as it's canceled. It doesn't
fully eliminate the chance of TooManyTimeout, but it does reduce it.
---
 src/browser/webapi/Window.zig | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/browser/webapi/Window.zig b/src/browser/webapi/Window.zig
index bbed1010..b89e7383 100644
--- a/src/browser/webapi/Window.zig
+++ b/src/browser/webapi/Window.zig
@@ -285,23 +285,23 @@ pub fn queueMicrotask(_: *Window, cb: js.Function, page: *Page) void {
 }
 
 pub fn clearTimeout(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
-    sc.removed = true;
+    var sc = self._timers.fetchRemove(id) orelse return;
+    sc.value.removed = true;
 }
 
 pub fn clearInterval(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
-    sc.removed = true;
+    var sc = self._timers.fetchRemove(id) orelse return;
+    sc.value.removed = true;
 }
 
 pub fn clearImmediate(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
-    sc.removed = true;
+    var sc = self._timers.fetchRemove(id) orelse return;
+    sc.value.removed = true;
 }
 
 pub fn cancelAnimationFrame(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
-    sc.removed = true;
+    var sc = self._timers.fetchRemove(id) orelse return;
+    sc.value.removed = true;
 }
 
 const RequestIdleCallbackOpts = struct {
@@ -319,8 +319,8 @@ pub fn requestIdleCallback(self: *Window, cb: js.Function.Temp, opts_: ?RequestI
 }
 
 pub fn cancelIdleCallback(self: *Window, id: u32) void {
-    var sc = self._timers.get(id) orelse return;
-    sc.removed = true;
+    var sc = self._timers.fetchRemove(id) orelse return;
+    sc.value.removed = true;
 }
 
 pub fn reportError(self: *Window, err: js.Value, page: *Page) !void {
@@ -704,7 +704,6 @@ const ScheduleCallback = struct {
         const window = page.window;
 
         if (self.removed) {
-            _ = window._timers.remove(self.timer_id);
             self.deinit();
             return null;
         }