1858040 - Investigate lazy function name for getter and setter functions

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P3)

Description

[Tooru Fujisawa [:arai]]

the combination of bug 1848278 and bug 1850197 is troublesome in term of binary size, because we'll have more static data for accessor function name, length, and hash.

But given the main target here is WebIDL properties, the accessor names are not likely be actually retrieved in regular website.

If we can make the accessor name calculation lazy, specifically, more lazy than CreateInterfaceObject, so that it's calculated only when the function name is actually accessed, we don't have to worry about the static data size or startup cost of those accessor names.

Comment 1

[Tooru Fujisawa [:arai]]

Using lazy name makes some operation around function name fallible, or returns unprefixed name.
all related parts should be updated to either get prefixed name with fallible operation, or use possibly-unprefixed name if it's only for debugging/information purpose

Comment 2

[Tooru Fujisawa [:arai]]

Attachment: Bug 1858040 - Part 1: Use FunctionKind::{Getter,Setter} for native functions created from JSPropertySpec. r?jandem!

Comment 3

[Tooru Fujisawa [:arai]]

Attachment: Bug 1858040 - Part 2: Add FunctionFlags::LAZY_ACCESSOR_NAME to lazily create accessor function name from unprefixed name. r?jandem!

For accessors with FunctionFlags::LAZY_ACCESSOR_NAME, JSFunction::AtomSlot
contains unprefixed name.

This patch also split existing methods and APIs for function name into 3:

1. infallible, and can return unprefixed name
2. fallible, and returns correct name
3. (internal only) infallibe, and returns correct name (only for functions known to not have FunctionFlags::LAZY_ACCESSOR_NAME)

If the result doesn't have to be exactly correct name, for example if it's for
debug logging or profiler marker, the 1st infallible functions are used.

Depends on D191456

Comment 4

[Tooru Fujisawa [:arai]]

Attachment: Bug 1858040 - Part 3: Use lazy name for accessors created with JSPropertySpec. r?jandem!

Depends on D191457

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f539af00cf91
Part 1: Use FunctionKind::{Getter,Setter} for native functions created from JSPropertySpec. r=jandem
https://hg.mozilla.org/integration/autoland/rev/750908d92ab1
Part 2: Add FunctionFlags::LAZY_ACCESSOR_NAME to lazily create accessor function name from unprefixed name. r=jandem
https://hg.mozilla.org/integration/autoland/rev/2744df17e06b
Part 3: Use lazy name for accessors created with JSPropertySpec. r=jandem

Comment 6

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/f539af00cf91
https://hg.mozilla.org/mozilla-central/rev/750908d92ab1
https://hg.mozilla.org/mozilla-central/rev/2744df17e06b

Comment 7

[Acasandrei Beatrice (needinfo me)]

(In reply to Pulsebot from comment #5)

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f539af00cf91
Part 1: Use FunctionKind::{Getter,Setter} for native functions created from
JSPropertySpec. r=jandem
https://hg.mozilla.org/integration/autoland/rev/750908d92ab1
Part 2: Add FunctionFlags::LAZY_ACCESSOR_NAME to lazily create accessor
function name from unprefixed name. r=jandem
https://hg.mozilla.org/integration/autoland/rev/2744df17e06b
Part 3: Use lazy name for accessors created with JSPropertySpec. r=jandem

== Change summary for alert #40074 (as of Mon, 30 Oct 2023 22:56:51 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
2%	Base Content JS	windows11-64-2009-shippable-qr	fission	1,575,078.00 -> 1,548,915.33
2%	Base Content JS	linux1804-64-shippable-qr	fission	1,572,616.00 -> 1,546,699.33
2%	Base Content JS	macosx1015-64-shippable-qr	fission	1,573,432.00 -> 1,547,512.00

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=40074

Comment 8

[Andrej (:aglavic)]

(In reply to Pulsebot from comment #5)

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f539af00cf91
Part 1: Use FunctionKind::{Getter,Setter} for native functions created from
JSPropertySpec. r=jandem
https://hg.mozilla.org/integration/autoland/rev/750908d92ab1
Part 2: Add FunctionFlags::LAZY_ACCESSOR_NAME to lazily create accessor
function name from unprefixed name. r=jandem
https://hg.mozilla.org/integration/autoland/rev/2744df17e06b
Part 3: Use lazy name for accessors created with JSPropertySpec. r=jandem

== Change summary for alert #40075 (as of Tue, 31 Oct 2023 00:23:19 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
55%	perf_reftest display-none-1.html	linux1804-64-shippable-qr	e10s fission stylo webrender-sw	0.56 -> 0.25
41%	perf_reftest_singletons display-none-1.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	1.01 -> 0.60
40%	perf_reftest_singletons display-none-1.html	windows10-64-shippable-qr	e10s fission stylo webrender	0.93 -> 0.56
40%	perf_reftest_singletons only-children-1.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	1.08 -> 0.65
39%	perf_reftest_singletons slow-selector-2.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	1.07 -> 0.65
...	...	...	...	...
7%	perf_reftest_singletons style-sharing-style-attr.html	linux1804-64-shippable-qr	e10s fission stylo webrender	6.01 -> 5.61

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=40075

Comment 9

[Nicolas Chevobbe [:nchevobbe]]

== Change summary for alert #40077 (as of Tue, 31 Oct 2023 00:26:59 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
5%	damp console.log-in-loop-content-process-window	windows10-64-shippable-qr	e10s fission stylo webrender	203.62 -> 192.78
5%	damp console.log-in-loop-content-process-window	windows10-64-shippable-qr	e10s fission stylo webrender-sw	203.53 -> 193.68

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=40077