Three related disposable-registration gaps that leak xterm Terminal
instances when the host application unmounts a Terminal. Evidence +
full writeup at juspay/kolu#606.
1. addon-webgl/WebglRenderer._cursorBlinkStateManager was declared
`= new MutableDisposable()` without the `this._register(...)`
wrapper that every sibling MutableDisposable in the class uses.
CursorBlinkStateManager runs a setInterval for the cursor blink
and its `dispose()` correctly clears it — but dispose() was never
called because the disposable wasn't registered. The live timer
kept the renderer (and thus the Terminal) alive past host
unmount.
2. common/TaskQueue.DebouncedIdleTask had no `dispose()` method.
Added one that clears the internal IdleTaskQueue (cancelling any
pending idle callback).
3. browser/services/RenderService._pausedResizeTask (a
DebouncedIdleTask) was not registered. Wrapped with
`this._register(...)` so RenderService.dispose propagates.
Verified in a downstream app (kolu) with a repro that toggles Focus
vs Canvas layout modes:
- Pre-fix: 24/28 disposed xterm Terminals retained past host unmount
+ forced GC.
- Post-fix: 0/28 retained.
Retention chain (before fix):
DOMTimer → ScheduledAction → V8Function
→ CursorBlinkStateManager._renderCallback → WebglRenderer
→ Terminal
Replace `window` with `globalThis` in IdleTaskQueue export.
In Bun and Deno, `isNode` is false but `window` is undefined, causing
a ReferenceError. Using `globalThis` is safe in all JS runtimes and
makes the `isNode` guard unnecessary.
This is the only `in window` expression in code bundled into
@xterm/headless.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
performance.now() is faster than Date.now() as there's no need to
consult the system clock. The more important part of this is that
performance.now() is monotonic and is guaranteed to never to backwards.
Sridhar Ratnakumar
GaubeeandClaude Opus 4.6
Daniel Imms
Jörg Breitbart