Improve hooks performance with a cold unmount queue

[JoviDeCroock]

Summary

• store the deferred passive-unmount queue on the after-paint flush function instead of in a mutable module-level binding
• pin the affected private hook property mangles so production output remains deterministic

This preserves passive cleanup ordering and deferred error routing while reducing the aggregate overhead measured in the Preact 11 hook paths.

Performance

Paired production Chromium runs against the previous Preact 11 build:

Octane suite	Geomean
js-framework	8.0% faster
memo-wall	11.4% faster
effectful-list	1.9% slower

All exact Octane correctness gates passed. The result is mixed at the individual-operation level: js-framework run and replace were 7.1% and 10.5% slower, while update/select/reorder/removal paths drove the aggregate improvement. The effectful-list result was mostly neutral, with remove_100_scattered 8.3% slower.

[github-actions]

📊 Tachometer Benchmark Results

Summary

duration

• create10k: unsure 🔍 -0% - +1% (-1.19ms - +5.88ms)
  ^{preact-local vs preact-main}
• filter-list: unsure 🔍 -0% - +1% (-0.02ms - +0.17ms)
  ^{preact-local vs preact-main}
• hydrate1k: unsure 🔍 -1% - +3% (-0.25ms - +1.26ms)
  ^{preact-local vs preact-main}
• many-updates: unsure 🔍 -2% - +2% (-0.28ms - +0.38ms)
  ^{preact-local vs preact-main}
• replace1k: unsure 🔍 -1% - +2% (-0.55ms - +1.27ms)
  ^{preact-local vs preact-main}
• text-update: unsure 🔍 -4% - +4% (-0.08ms - +0.07ms)
  ^{preact-local vs preact-main}
• todo: unsure 🔍 -2% - +1% (-0.52ms - +0.23ms)
  ^{preact-local vs preact-main}
• update10th1k: unsure 🔍 -5% - +3% (-2.04ms - +1.34ms)
  ^{preact-local vs preact-main}

usedJSHeapSize

• create10k: unsure 🔍 -0% - +0% (-0.04ms - +0.02ms)
  ^{preact-local vs preact-main}
• filter-list: unsure 🔍 -0% - +0% (-0.00ms - +0.00ms)
  ^{preact-local vs preact-main}
• hydrate1k: unsure 🔍 -2% - +3% (-0.09ms - +0.15ms)
  ^{preact-local vs preact-main}
• many-updates: unsure 🔍 -0% - +0% (-0.00ms - +0.00ms)
  ^{preact-local vs preact-main}
• replace1k: unsure 🔍 -0% - +0% (-0.00ms - +0.00ms)
  ^{preact-local vs preact-main}
• text-update: unsure 🔍 -2% - +5% (-0.02ms - +0.05ms)
  ^{preact-local vs preact-main}
• todo: unsure 🔍 -0% - +0% (-0.00ms - +0.00ms)
  ^{preact-local vs preact-main}
• update10th1k: unsure 🔍 -0% - +0% (-0.01ms - +0.01ms)
  ^{preact-local vs preact-main}

Results

create10k

• Browser: chrome-headless
• Sample size: 50
• Built by: CI #5824

• Commit: 90789f0

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	839.33ms - 843.85ms	-	unsure 🔍 -0% - +1% -1.19ms - +5.88ms
preact-main	836.53ms - 841.95ms	unsure 🔍 -1% - +0% -5.88ms - +1.19ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	19.21ms - 19.25ms	-	unsure 🔍 -0% - +0% -0.04ms - +0.02ms
preact-main	19.22ms - 19.26ms	unsure 🔍 -0% - +0% -0.02ms - +0.04ms	-

filter-list

• Browser: chrome-headless
• Sample size: 50
• Built by: CI #5824

• Commit: 90789f0

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	16.52ms - 16.70ms	-	unsure 🔍 -0% - +1% -0.02ms - +0.17ms
preact-main	16.52ms - 16.55ms	unsure 🔍 -1% - +0% -0.17ms - +0.02ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	1.56ms - 1.57ms	-	unsure 🔍 -0% - +0% -0.00ms - +0.00ms
preact-main	1.56ms - 1.57ms	unsure 🔍 -0% - +0% -0.00ms - +0.00ms	-

hydrate1k

• Browser: chrome-headless
• Sample size: 50
• Built by: CI #5824

• Commit: 90789f0

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	41.31ms - 42.56ms	-	unsure 🔍 -1% - +3% -0.25ms - +1.26ms
preact-main	41.02ms - 41.84ms	unsure 🔍 -3% - +1% -1.26ms - +0.25ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	4.99ms - 5.19ms	-	unsure 🔍 -2% - +3% -0.09ms - +0.15ms
preact-main	4.98ms - 5.13ms	unsure 🔍 -3% - +2% -0.15ms - +0.09ms	-

many-updates

• Browser: chrome-headless
• Sample size: 50
• Built by: CI #5824

• Commit: 90789f0

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	16.04ms - 16.61ms	-	unsure 🔍 -2% - +2% -0.28ms - +0.38ms
preact-main	16.11ms - 16.44ms	unsure 🔍 -2% - +2% -0.38ms - +0.28ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	3.75ms - 3.76ms	-	unsure 🔍 -0% - +0% -0.00ms - +0.00ms
preact-main	3.75ms - 3.76ms	unsure 🔍 -0% - +0% -0.00ms - +0.00ms	-

replace1k

• Browser: chrome-headless
• Sample size: 100
• Built by: CI #5824

• Commit: 90789f0

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	55.67ms - 57.03ms	-	unsure 🔍 -1% - +2% -0.55ms - +1.27ms
preact-main	55.39ms - 56.58ms	unsure 🔍 -2% - +1% -1.27ms - +0.55ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	3.03ms - 3.03ms	-	unsure 🔍 -0% - +0% -0.00ms - +0.00ms
preact-main	3.03ms - 3.03ms	unsure 🔍 -0% - +0% -0.00ms - +0.00ms	-

run-warmup-0

Version	Avg time	vs preact-local	vs preact-main
preact-local	26.96ms - 27.71ms	-	unsure 🔍 -3% - +1% -0.91ms - +0.19ms
preact-main	27.29ms - 28.11ms	unsure 🔍 -1% - +3% -0.19ms - +0.91ms	-

run-warmup-1

Version	Avg time	vs preact-local	vs preact-main
preact-local	32.52ms - 33.79ms	-	unsure 🔍 -3% - +3% -0.96ms - +0.86ms
preact-main	32.56ms - 33.86ms	unsure 🔍 -3% - +3% -0.86ms - +0.96ms	-

run-warmup-2

Version	Avg time	vs preact-local	vs preact-main
preact-local	31.98ms - 33.61ms	-	unsure 🔍 -5% - +2% -1.51ms - +0.83ms
preact-main	32.30ms - 33.97ms	unsure 🔍 -3% - +5% -0.83ms - +1.51ms	-

run-warmup-3

Version	Avg time	vs preact-local	vs preact-main
preact-local	25.96ms - 26.30ms	-	unsure 🔍 -1% - +0% -0.37ms - +0.11ms
preact-main	26.09ms - 26.43ms	unsure 🔍 -0% - +1% -0.11ms - +0.37ms	-

run-warmup-4

Version	Avg time	vs preact-local	vs preact-main
preact-local	27.04ms - 28.20ms	-	unsure 🔍 -5% - +1% -1.31ms - +0.22ms
preact-main	27.66ms - 28.67ms	unsure 🔍 -1% - +5% -0.22ms - +1.31ms	-

run-final

Version	Avg time	vs preact-local	vs preact-main
preact-local	21.18ms - 21.56ms	-	unsure 🔍 -1% - +2% -0.19ms - +0.35ms
preact-main	21.10ms - 21.47ms	unsure 🔍 -2% - +1% -0.35ms - +0.19ms	-

text-update

• Browser: chrome-headless
• Sample size: 200
• Built by: CI #5824

• Commit: 90789f0

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	1.93ms - 2.04ms	-	unsure 🔍 -4% - +4% -0.08ms - +0.07ms
preact-main	1.93ms - 2.04ms	unsure 🔍 -4% - +4% -0.07ms - +0.08ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	1.05ms - 1.10ms	-	unsure 🔍 -2% - +5% -0.02ms - +0.05ms
preact-main	1.04ms - 1.09ms	unsure 🔍 -5% - +2% -0.05ms - +0.02ms	-

todo

• Browser: chrome-headless
• Sample size: 50
• Built by: CI #5824

• Commit: 90789f0

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	28.49ms - 29.04ms	-	unsure 🔍 -2% - +1% -0.52ms - +0.23ms
preact-main	28.67ms - 29.16ms	unsure 🔍 -1% - +2% -0.23ms - +0.52ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	1.28ms - 1.28ms	-	unsure 🔍 -0% - +0% -0.00ms - +0.00ms
preact-main	1.28ms - 1.28ms	unsure 🔍 -0% - +0% -0.00ms - +0.00ms	-

update10th1k

• Browser: chrome-headless
• Sample size: 70
• Built by: CI #5824

• Commit: 90789f0

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	42.07ms - 44.55ms	-	unsure 🔍 -5% - +3% -2.04ms - +1.34ms
preact-main	42.51ms - 44.81ms	unsure 🔍 -3% - +5% -1.34ms - +2.04ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	2.97ms - 2.98ms	-	unsure 🔍 -0% - +0% -0.01ms - +0.01ms
preact-main	2.97ms - 2.98ms	unsure 🔍 -0% - +0% -0.01ms - +0.01ms	-

_{tachometer-reporter-action v2 for CI}

[github-actions]

Size Change: +8 B (+0.05%)

Total Size: 15.8 kB

📦 View Changed

Filename	Size	Change
hooks/dist/hooks.mjs	1.57 kB	+8 B (+0.51%)

ℹ️ View Unchanged

Filename	Size
compat/dist/compat.mjs	3.89 kB
debug/dist/debug.mjs	3.88 kB
devtools/dist/devtools.mjs	274 B
dist/preact.mjs	4.88 kB
jsx-runtime/dist/jsxRuntime.mjs	856 B
test-utils/dist/testUtils.mjs	473 B

_{compressed-size-action}

[coveralls]

coverage: 99.298% (+0.001%) from 99.297% — perf/cold-unmount-queue into main