chore: remove `UNOWNED` flag #17105

Rich-Harris · 2025-11-03T22:36:06Z

This makes good on my threat in #17102 (comment) to sort out all the convoluted nonsense around UNOWNED and DISCONNECTED deriveds. We've made this far more complicated than it needs to be. All we need to do is push the current signal to its dependencies' reactions when the signal is connected to the graph, and skip doing so when it isn't.

Fixes #17024
Fixes #17049 (comment) (and therefore everything that was still buggy in that issue I think)

Most benchmarks are unaffected, but where there is a significant effect, this branch is much faster.

results of `pnpm bench:compare`

sbench_create_signals
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 367.63ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 373.89ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 160.79ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 164.47ms
sbench_create_0to1
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 6.16ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  5.93ms
sbench_create_1to1
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 21.26ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 21.05ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.02ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 2.96ms
sbench_create_2to1
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 18.48ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 18.42ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  2.92ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.00ms
sbench_create_4to1
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 17.03ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 16.77ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.01ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 2.97ms
sbench_create_1000to1
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 14.87ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 14.95ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 2.85ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 2.91ms
sbench_create_1to2
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 10.63ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 10.59ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 0.77ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼   0.71ms
sbench_create_1to4
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 8.72ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 8.82ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  0.51ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 0.54ms
sbench_create_1to8
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 7.42ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  7.21ms
sbench_create_1to1000
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 8.60ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 8.57ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  0.63ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 0.67ms
kairo_avoidable_owned
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 513.85ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 511.03ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  36.68ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 38.50ms
kairo_avoidable_unowned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼     499.87ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 612.69ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  36.09ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 38.70ms
kairo_broad_owned
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 501.31ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 499.64ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 4.13ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼   3.68ms
kairo_broad_unowned
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 499.73ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 498.98ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 4.11ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼   3.71ms
kairo_deep_owned
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 218.20ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 214.63ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 2.82ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 2.78ms
kairo_deep_unowned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼                 212.50ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 1011.22ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼      2.86ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.75ms
kairo_diamond_owned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 418.69ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 421.05ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 22.13ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 22.09ms
kairo_diamond_unowned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼    409.05ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 495.23ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  21.79ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 22.39ms
kairo_triangle_owned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 127.22ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 130.11ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  4.06ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 4.18ms
kairo_triangle_unowned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼           123.38ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 246.39ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 4.36ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  4.05ms
kairo_mux_owned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  328.77ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 345.10ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 2.90ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 2.87ms
kairo_mux_unowned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼        326.24ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 494.95ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.10ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  3.01ms
kairo_repeated_owned
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 80.15ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 79.85ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼   2.95ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.28ms
kairo_repeated_unowned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  75.69ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 78.93ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.53ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼   3.20ms
kairo_unstable_owned
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 120.92ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  117.36ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.95ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  3.84ms
kairo_unstable_unowned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼   118.29ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 133.75ms
  gc_time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.98ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 3.90ms
mol_bench_owned
  time: fastest is b (main)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 286.63ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 285.10ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 0.93ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 0.94ms
mol_bench_unowned
  time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼  286.43ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 304.27ms
  gc_time: fastest is a (remove-unowned)
    a: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼    1.01ms
    b: ◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼◼ 1.17ms

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changeset-bot · 2025-11-03T22:36:09Z

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github-actions · 2025-11-03T22:37:42Z

Playground

pnpm add https://pkg.pr.new/svelte@17105

dummdidumm

This looks promising - what I don't quite understand at the moment is how it's safe that something counts as owned as long as it has any reactions

packages/svelte/src/internal/client/constants.js

packages/svelte/src/internal/client/reactivity/effects.js

Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>

Rich-Harris · 2025-11-04T14:24:14Z

There is no concept of ownership any more — something is either connected (in which case it will be notified of changes to its dependencies, and will in turn notify its dependents) or it isn't. We don't need to care if a derived is owned or not

* fix: delete from batch_values on updates This fixes a bug where a derived would still show its old value even after it was indirectly updated again within the same batch. This can for example happen by reading a derived on an effect, then writing to a source in that same effect that makes the derived update, and then read the derived value in a sibling effect - it still shows the old value without the fix. The fix is to _delete_ the value from batch_values, as it's now the newest value across all batches. In order to not prevent breakage on other batches we have to leave the status of deriveds as-is, i.e. within is_dirty and update_derived we cannot update its status. That might be a bit more inefficient as you now have to traverse the graph for each `get` of that derived (it's a bit like they are all disconnected) but we can always optimize that later if need be. Another advantage of this fix is that we can get rid of duplicate logic we had to add about unmarking and reconnecting deriveds, because that logic was only needed for the case where deriveds are read after they are updated, which now no longer hits that if-branch * keep derived cache, but clear it in mark_reactions (#17116) --------- Co-authored-by: Rich Harris <rich.harris@vercel.com>

packages/svelte/src/internal/client/runtime.js

dummdidumm

Fantastic work

Rich-Harris added 11 commits November 3, 2025 10:58

chore: remove unowned check when calling e.effect_in_unowned_derived

64f078d

WIP

c9d26db

all non-unit tests passing

db21188

tidy

b5bb6fb

WIP

625d289

WIP

6700adb

WIP

697fba0

note to self

6eb4dee

fix

93f277d

fix

e1fbee5

hmm maybe not

b61d1b0

Merge branch 'main' into remove-unowned

5b42362

try this

15f9f85

dummdidumm reviewed Nov 4, 2025

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packages/svelte/src/internal/client/constants.js Outdated Show resolved Hide resolved

packages/svelte/src/internal/client/reactivity/effects.js Outdated Show resolved Hide resolved

Rich-Harris and others added 5 commits November 4, 2025 09:01

simplify

67f544e

remove skip_reaction

d1149d6

docs

d5c7605

add changeset, in case this results in changed behaviour

0bd13a9

Update packages/svelte/src/internal/client/reactivity/effects.js

3197022

Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>

Rich-Harris marked this pull request as ready for review November 4, 2025 14:24

Rich-Harris and others added 7 commits November 4, 2025 09:28

fix #17024

4d5209c

fix comment

b8fc364

revert

3d4fa95

fix

027194a

dry

69290af

changeset

c96eb44

fix WAS_MARKED logic

1032b31

failing test (that uncovered other unrelated bug) + fix

22435b2

dummdidumm mentioned this pull request Nov 5, 2025

fix: delete from batch_values on updates #17115

Merged

Rich-Harris commented Nov 5, 2025

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packages/svelte/src/internal/client/runtime.js Show resolved Hide resolved

Rich-Harris added 2 commits November 5, 2025 14:25

tidy up

df077f3

Merge branch 'main' into remove-unowned

66d6d4b

dummdidumm approved these changes Nov 6, 2025

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dummdidumm merged commit 46e9d2d into main Nov 6, 2025
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dummdidumm deleted the remove-unowned branch November 6, 2025 10:47

github-actions bot mentioned this pull request Nov 6, 2025

Version Packages #17119

Merged

This was referenced Nov 6, 2025

chore: remove unowned check when calling e.effect_in_unowned_derived #17103

Closed

fix: reconnect disconnect deriveds after batch processing #17102

Closed

fix: traverse graph when time traveling #17095

Closed

This was referenced Nov 6, 2025

Popover content invisible with async svelte huntabyte/bits-ui#1881

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fix(floating-layer): missing effect dependency huntabyte/bits-ui#1882

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bits-ui Popover doesn't open #17109

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chore: remove `UNOWNED` flag #17105

chore: remove `UNOWNED` flag #17105

Rich-Harris commented Nov 3, 2025 •

edited by dummdidumm

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chore: remove UNOWNED flag #17105

chore: remove UNOWNED flag #17105

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Rich-Harris commented Nov 3, 2025 • edited by dummdidumm Loading Uh oh! There was an error while loading. Please reload this page.

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Before submitting the PR, please make sure you do the following

Tests and linting

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chore: remove `UNOWNED` flag #17105

chore: remove `UNOWNED` flag #17105

Rich-Harris commented Nov 3, 2025 •

edited by dummdidumm

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changeset-bot bot commented Nov 3, 2025 •

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