fix(signals): close the probe's state around a memo isPending pulls (#4429) by ryansolid · Pull Request #4465 · solidjs/solid

ryansolid · 2026-10-30T13:44:25Z

Before: verdictValue pulls a dirty memo with the dispatch closed (setVerdict(null); A31 says the pulled memo's pass is its own), but it left probing set. A latest() the pulled memo called itself then re-entered the window with the outer probe's state:

latest() of a born-held node took the probe's joinPass arm, so the memo's pass joined the hold and its value was held with it.
A flight its latest() read set probeFound, so the outer isPending answered for the memo's reads instead of for the memo.

After: a memo pulled inside isPending() computes as its own pass. A latest() it calls doesn't join a hold through the probe, and its reads don't answer the outer isPending.

How: verdictValue saves probing, clears it for the pulled pass, and restores it afterwards. Clearing latestActive too would have cost +25 B. That case (inside latest(fn), a pulled memo's own isPending of a held write answers final) is left for its own PR.

Size vs next, measured locally (linux): +13 B minified only on bundles that ship isPending/latest, +9 B brotli on + isPending/latest. Hello world +0. No cap changes.

Tests: new packages/signals/tests/probe-pulled-pass-4429.test.ts, which fails on next. Signals 6,027 passed. Web 1,560, hydrate 716 and solid 916 passed. Server 1,905 passed; the only failure is the known #3311 one. Solid's cross-package-fields fails on next too.

Fixes #4429

Generated by Claude Code

…4429) `verdictValue` pulls a dirty memo with the dispatch closed (`setVerdict(null)`, A31: the pulled memo's pass is its own) but left `probing` and `latestActive` set. A `latest()` / `isPending()` the pulled memo made itself re-entered the window with the outer probe's state: - `latest()` of a born-held node took the probe's `joinPass` arm, so the memo's pass joined the hold and its value was held with it; - a flight its `latest()` read set `probeFound`, so the outer `isPending` answered for the memo's reads, not for the memo; - inside `latest(fn)`, the memo's own `isPending` of a held write read as a probe inside a `latest` window and answered final. Each depended on who woke the memo. Save and clear both flags around the pull, as the dispatch already is. `probeFound` needs no save: it is only set while `probing`. Fixes #4429 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

Resolves verdict.ts beside #4438's shadow hook (the window's state is restored before the shadow's decision point) and the generated RULES-INDEX.md (regenerated). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

Narrow the fix to `probing`, the state #4429 names: +9 B brotli / +13 B minified on `+ isPending/latest`, where clearing `latestActive` too cost +25 / +25. `latestActive` leaks the same way (inside `latest(fn)`, a pulled memo's own `isPending` of a held write answers final); that is left for its own issue and decision. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

… pass) Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

…fied) Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

…-x1ore2-4429 # Conflicts: # scripts/size/scenarios.js

…-x1ore2-4429

…minified) Frozen floor 38.76 KB -> 38.80 KB, recorded minified 117,227 -> 117,328 B (+13 B this fix; the rest is next's growth since the floor was recorded). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

…-x1ore2-4429 # Conflicts: # scripts/size/floor-caps.json # scripts/size/scenarios.js

…-x1ore2-4429

changeset-bot · 2026-10-30T13:44:31Z

🦋 Changeset detected

Latest commit: ff76ebc

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 15 packages

Name	Type
@solidjs/signals	Patch
test-integration	Patch
@solidjs/web	Patch
@solidjs/babel-plugin	Patch
@solidjs/compiler	Patch
@solidjs/diagnostics	Patch
@solidjs/element	Patch
@solidjs/h	Patch
@solidjs/html	Patch
solid-js	Patch
@solidjs/universal	Patch
board-example	Patch
canvas-example	Patch
server-dbmon-example	Patch
todos-server-example	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

github-actions · 2026-10-30T13:49:53Z

Size (brotli, eager entry chunk)

scenario	head	vs base	minified vs base	minified vs recorded	cap		lazy chunks (not counted)
signals: core floor (createSignal/Memo/Effect/Root/flush)	7.42 KB	0 B	0 B	+15 B	7.43 KB	✅
signals: + createStore	14.96 KB	0 B	0 B	+6 B	14.97 KB	✅
signals: + isPending/latest	11.11 KB	+7 B (+0.1%)	+13 B	+15 B	11.12 KB	✅
signals: + until/refresh (truth readers, no optimism)	8.05 KB	0 B	0 B	+2 B	8.06 KB	✅
app: render + one signal (the simple-app floor)	9.78 KB	0 B	0 B	+15 B	9.78 KB	✅
app: hydrating (no stores) with Show/For/Loading/Errored/lazy	18.73 KB	0 B	0 B	+15 B	18.74 KB	✅	lazy-page.js 0.04 KB
app: hydrating + every store primitive family	32.37 KB	0 B	0 B	+6 B	32.48 KB	✅	lazy-page.js 0.04 KB
app: CSR with Show/For/Loading/Errored/lazy	13.43 KB	0 B	0 B	+2 B	13.47 KB	✅	lazy-page.js 0.04 KB
app: CSR, observe tier (same app on the `observe` artifacts)	15.19 KB	0 B	0 B	+2 B	15.20 KB	✅	lazy-page.js 0.04 KB
app: CSR, observe tier + attribution engine enabled	29.76 KB	0 B	0 B	+2 B	29.78 KB	✅	lazy-page.js 0.04 KB
app: compiled floor (one template, one text hole, one delegated click)	9.97 KB	0 B	0 B	+2 B	9.98 KB	✅
app: compiled CSR (JSX todo app: spread/merge/omit, events, class/style, keyed For, Show, Loading + lazy, store)	26.33 KB	0 B	0 B	+6 B	26.33 KB	✅	stats.js 0.18 KB
app: compiled hydrating (the same JSX todo app through hydrate(), compiled hydratable)	32.52 KB	0 B	0 B	0 B	32.54 KB	✅	stats.js 0.20 KB
frames: eager client consumer (frames client + transport, lazy codec)	11.75 KB	0 B	0 B	0 B	11.77 KB	✅
page: base server components (hydrating + dynamic + frames + sf reference)	33.67 KB	0 B	0 B	+2 B	33.77 KB	✅	assets.js 0.78 KB, decode.js 7.09 KB, lazy-page.js 0.04 KB, regions.js 1.06 KB, trace.js 9.03 KB, wire.js 3.47 KB
page: live server components (base + live/GET + action + isPending/latest)	38.78 KB	+20 B (+0.1%)	+13 B	+15 B	38.85 KB	✅	assets.js 0.78 KB, decode.js 7.09 KB, lazy-page.js 0.04 KB, regions.js 1.06 KB, trace.js 9.03 KB, wire.js 3.47 KB
page: compiled base server components (the base page as JSX: templates with class/style/attributes/events, For/Show; no spread)	35.70 KB	0 B	0 B	+2 B	35.72 KB	✅	assets.js 0.78 KB, decode.js 7.09 KB, regions.js 1.06 KB, sc-comments.js 0.20 KB, trace.js 9.01 KB, wire.js 3.47 KB
page: compiled live server components (the compiled base page + live/GET + action + isPending/latest)	42.71 KB	+21 B (+0.0%)	+13 B	+15 B	42.73 KB	✅	eager (counted): web.js 22.75 KB; assets.js 0.78 KB, decode.js 7.09 KB, regions.js 1.07 KB, sc-comments.js 0.19 KB, trace.js 9.05 KB, wire.js 3.47 KB
page: base + router (base page + @solidjs/router: createRouter, two routes, preload, useNavigate)	41.23 KB	0 B	0 B	0 B	41.25 KB	✅	assets.js 0.78 KB, decode.js 7.09 KB, lazy-page.js 0.04 KB, regions.js 1.06 KB, server.js 1.03 KB, serverForms.js 3.57 KB, trace.js 9.03 KB, wire.js 3.48 KB
page: live + router (live page + @solidjs/router: createRouter, two routes, preload, useNavigate)	48.42 KB	−11 B (−0.0%)	+13 B	+15 B	48.44 KB	✅	eager (counted): client.js 27.94 KB; assets.js 0.78 KB, decode.js 7.09 KB, lazy-page.js 0.04 KB, regions.js 1.07 KB, server.js 1.03 KB, serverForms.js 3.30 KB, trace.js 9.03 KB, wire.js 3.49 KB
server: floor (getRequestEvent + isServer)	1.27 KB	0 B	0 B	0 B	1.29 KB	✅
server: renderToString (the server-render floor)	22.79 KB	0 B	0 B	0 B	22.80 KB	✅

_{Bundled with Rolldown (what Vite ships), brotli q11, decimal KB. A scenario fails only when it is over its brotli cap and its minified size is more than 20 B over the minified recorded with the cap; over the cap within that allowance is brotli layout noise and passes with a warning. Caps and their recorded minified in scripts/size/scenarios.js; the floor and page caps in floor-caps.json are frozen (lower only, or Size-Exception: in the PR body). npm run ratchet lowers caps per RC; it never raises one (scripts/size/README.md).}

coveralls · 2026-10-30T13:57:17Z

Coverage Report for CI Build 41079575274

Coverage remained the same at 78.1%

Details

Coverage remained the same as the base build.
Patch coverage: No coverable lines changed in this PR.
No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

Coverage Stats


Relevant Lines:	1362
Covered Lines:	1125
Line Coverage:	82.6%
Relevant Branches:	1090
Covered Branches:	790
Branch Coverage:	72.48%
Branches in Coverage %:	Yes
Coverage Strength:	29.8 hits per line

💛 - Coveralls

codspeed · 2026-10-30T14:10:17Z

Merging this PR will improve performance by 12.63%

1 warning

⚠️ 3 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

⚡ 1 improved benchmark
✅ 199 untouched benchmarks
⏩ 5 skipped benchmarks¹

Performance Changes

	Benchmark	`BASE`	`HEAD`	Efficiency
⚡	`projection derive: write one NESTED field (reference)`	2.4 ms	2.2 ms	+12.63%

Tip

Curious why performance improved? Comment @codspeedbot explain why performance improved on this PR, or directly use the CodSpeed MCP with your agent.

_{Comparing claude/project-thread-x1ore2-4429 (ff76ebc) with next (e49b0c7)}

5 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

ryansolid · 2026-10-30T14:10:34Z

I don't think either CodSpeed flag comes from this PR. The base (next cddaa76) recorded both benches fast, and other PRs on that base show the same drops with unrelated diffs.

projection-root-write "write one NESTED field (reference)", −13.3%. fix(signals): a merged transaction's verdict lane is the same hold's at the D-28 seat (#4427) #4455, fix(signals): a staged error reaches the memos and derived stores that derive from it #4456 and fix(signals): a derived store's propagated error reaches its readers once #4463 show −13.2% to −13.5%. This bench is a sync store write with no hold, so it never reaches verdictValue.
non-ascii-template "arrow in template", −9.2%. fix(signals): a first answer landing in the tick a write re-asks it is answered, then re-asked (D-22, F-9) #4459 shows −9.21%. This bench is a sync renderToString with no async memo, and that is the only path the probing save/restore runs on.

I'm treating both as base-outlier noise.

Generated by Claude Code

…-x1ore2-4429

The probe now restores `probing` around a pulled pass, so the entry can only hide a regression. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

…-x1ore2-4429

claude added 11 commits October 30, 2026 08:45

chore: keep the #4425 spec as next has it (undo the merge's formatter…

d47a5dc

… pass) Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

Merge origin/next into claude/project-thread-x1ore2-4429

f00f367

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

chore(size): raise the compiled live page's cap for #4429 (+13 B mini…

caf0804

…fied) Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

Merge remote-tracking branch 'origin/next' into claude/project-thread…

462ebd4

…-x1ore2-4429 # Conflicts: # scripts/size/scenarios.js

Merge remote-tracking branch 'origin/next' into claude/project-thread…

d8f1b3f

…-x1ore2-4429

Merge remote-tracking branch 'origin/next' into claude/project-thread…

fe24042

…-x1ore2-4429 # Conflicts: # scripts/size/floor-caps.json # scripts/size/scenarios.js

Merge remote-tracking branch 'origin/next' into claude/project-thread…

6733811

…-x1ore2-4429

claude added 2 commits October 30, 2026 14:42

Merge remote-tracking branch 'origin/next' into claude/project-thread…

be458db

…-x1ore2-4429

test(signals): drop the seat shadow's known entry for #4429

0bc0adb

The probe now restores `probing` around a pulled pass, so the entry can only hide a regression. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

Merge remote-tracking branch 'origin/next' into claude/project-thread…

ff76ebc

…-x1ore2-4429

ryansolid merged commit ab3d2ad into next Oct 30, 2026
8 checks passed

This was referenced Oct 30, 2026

[2.0 / next] probing leaks into a memo's pass pulled inside isPending — a nested latest() joins the pass to the hold #4429

Closed

test(web): async-gen E1 accepts D-28's grouped first-load stop (#17) #4476

Merged

Navigation Menu

Repository navigation

fix(signals): close the probe's state around a memo isPending pulls (#4429) - #4465

fix(signals): close the probe's state around a memo isPending pulls (#4429)#4465
ryansolid merged 14 commits into
nextfrom
claude/project-thread-x1ore2-4429

ryansolid commented Oct 30, 2026

Uh oh!

changeset-bot Bot commented Oct 30, 2026 •

edited

Loading

Uh oh!

github-actions Bot commented Oct 30, 2026 •

edited

Loading

Uh oh!

coveralls commented Oct 30, 2026 •

edited

Loading

Uh oh!

codspeed Bot commented Oct 30, 2026 •

edited

Loading

Uh oh!

ryansolid commented Oct 30, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

ryansolid commented Oct 30, 2026

Uh oh!

changeset-bot Bot commented Oct 30, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

🦋 Changeset detected

Uh oh!

github-actions Bot commented Oct 30, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Size (brotli, eager entry chunk)

Uh oh!

coveralls commented Oct 30, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Coverage Report for CI Build 41079575274

Coverage remained the same at 78.1%

Details

Uncovered Changes

Coverage Regressions

Coverage Stats

💛 - Coveralls

Uh oh!

codspeed Bot commented Oct 30, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Merging this PR will improve performance by 12.63%

Performance Changes

Footnotes

Uh oh!

ryansolid commented Oct 30, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

changeset-bot Bot commented Oct 30, 2026 •

edited

Loading

github-actions Bot commented Oct 30, 2026 •

edited

Loading

coveralls commented Oct 30, 2026 •

edited

Loading

codspeed Bot commented Oct 30, 2026 •

edited

Loading