fix: memory leak in animation frame window disposal

[Simon Siefke (SimonSiefke)]

Details

The animation-frame scheduler keeps queues and flags for each window in four global maps. Closing an auxiliary window leaves its entries behind. If the window closes before its next frame, canceled callbacks can also stay in its queue.

Change

Remove the closed window from all four maps and clear any queue currently being processed. Ignore a late frame callback after cleanup, and avoid recreating the running flag when a callback closes its own window.

Before

Opening and closing an auxiliary editor window 37 times grows each animation queue map from 3 to 40 entries. The chart shows all named-function growth rows.

After

Both animation queue maps stay at one entry for the live main window. Five unrelated named-function rows remain. The outlined menu rows disappear in this comparison, but their change has not been traced to this fix.

Test Video

test.mp4

_{AI disclosure: Model: GPT-6-Astra. Worktime: 14 min}

[Copilot]

Copilot review overview

🟢 Approval recommended

The cleanup correctly handles pending and active queues, with focused regression coverage.

Review effort: Balanced
Findings: None

What changed in this PR

Fixes animation-frame scheduler leaks when auxiliary windows close.

Changes:

• Clears per-window animation queues and state during unregistration.
• Safely ignores late frame callbacks and mid-frame window disposal.
• Adds lifecycle, cancellation, priority, and scheduling tests.

File	Description
src/​vs/​base/​browser/​dom.ts	Cleans animation-frame state when windows unregister.
src/​vs/​base/​test/​browser/​animationFrame.test.ts	Tests cleanup and scheduling behavior.

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[Dmitriy Vasyura (dmitrivMS)]

Simon Siefke (@SimonSiefke) Thank you!