perf(allocator): reduce time `Mutex` lock is held in `FixedSizeAllocatorPool::get` by overlookmotel · Pull Request #17079 · oxc-project/oxc

overlookmotel · 2025-12-18T22:16:12Z

Follow-on after #17023. Small perf optimization.

Minimize the time that the Mutex is locked, by dropping the MutexGuard before checking whether pop() returned Some or not , rather than after.

overlookmotel · 2025-12-18T22:16:30Z

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

0-merge - adds this PR to the back of the merge queue
hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

_{An organization admin has enabled the Graphite Merge Queue in this repository.} _{Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.}

This stack of pull requests is managed by Graphite. Learn more about stacking.

Copilot

Pull request overview

This PR optimizes the performance of FixedSizeAllocatorPool::get by reducing the time the mutex lock is held. The optimization moves the if let pattern matching and into_inner() call outside the critical section, minimizing mutex contention in multi-threaded scenarios.

Key changes:

Refactored mutex locking pattern to release the lock immediately after pop() in both the initial pool check and the condition variable wait loop
Applied the same optimization pattern already used in StandardAllocatorPool::get

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

codspeed-hq · 2025-12-18T22:24:32Z

CodSpeed Performance Report

Merging #17079 will not alter performance

_{Comparing om/12-18-perf_allocator_reduce_time_mutex_lock_is_held_in_fixedsizeallocatorpool_get_ (2df9b9c) with om/12-18-refactor_allocator_move_nested_function_out_of_fixedsizeallocatorpool_get_ (348c622)}

Summary

✅ 42 untouched
⏩ 3 skipped¹

3 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. ↩

graphite-app · 2025-12-18T23:39:46Z

Merge activity

Dec 18, 11:39 PM UTC: overlookmotel added this pull request to the Graphite merge queue.
Dec 18, 11:51 PM UTC: Merged by the Graphite merge queue.

…torPool::get` (#17079) Follow-on after #17023. Small perf optimization. Minimize the time that the `Mutex` is locked, by dropping the `MutexGuard` before checking whether `pop()` returned `Some` or not , rather than after.

### 🚀 Features - d209c21 allocator: Add cap to FixedSizeAllocatorPool and block when exhausted (#17023) (Cameron) - fb2af91 allocator: Add bitset utils (#17042) (zhaoting zhou) - c16082c tasks/compat_data: Integrate `node-compat-table` (#16831) (Boshen) - 5586823 span: Extract TS declaration file check to its own function (#17037) (camchenry) - 3d2b492 minifier: Fold iife arrow functions in call expressions (#16477) (Armano) - 67e9f9e codegen: Keep comments on the export specifiers (#16943) (夕舞八弦) - cb515fa parser: Improve error message for `yield` as identifier usage (#16950) (sapphi-red) - dcc856b parser: Add help for `new_dynamic_import` error (#16949) (sapphi-red) - c3c79f8 parser: Improve import attribute value error message (#16948) (sapphi-red) - 291b57b ast_tools: Generate TS declaration files for deserializer and walk files (#16912) (camc314) - 74eae13 minifier: Remove unused import specifiers (#16797) (camc314) ### 🐛 Bug Fixes - fb9e193 linter: OOM problems with custom plugins (#17082) (overlookmotel) - e59132b parser/napi: Fix lazy deser (#17069) (overlookmotel) - a92faf0 ast_tools: Support `u128` in `assert_layouts` generator (#17050) (overlookmotel) - 47b4c2f minifier/docs: Correct hyperlink path in OPTIMIZATIONS.md (#16986) (GRK) - 3002649 transformer/typescript: Remove unused import equals declaration (#16776) (Dunqing) - 5a2af88 regular_expression: Correct named capture group reference error (#16952) (sapphi-red) ### ⚡ Performance - b657bb6 allocator: Reduce time `Mutex` lock is held in `FixedSizeAllocatorPool::get` (#17079) (overlookmotel) - 1f3b19b ast: `#[ast]` macro use `#[repr(transparent)]` for single-field structs (#17052) (overlookmotel) - 225f229 parser: Use SmallVec for duplicate default export detection (#16801) (camc314) ### 📚 Documentation - a9c419f traverse: Update safety comments (#16944) (overlookmotel) Co-authored-by: overlookmotel <557937+overlookmotel@users.noreply.github.com>

This was referenced Dec 18, 2025

fix(linter): OOM problems with custom plugins #17013

Merged

refactor(allocator/fixed-size): return Result from allocation instead of panicking #17022

Merged

refactor(allocator): remove AllocError from fixed size allocator #17077

Merged

github-actions bot added the C-performance Category - Solution not expected to change functional behavior, only performance label Dec 18, 2025

overlookmotel marked this pull request as ready for review December 18, 2025 22:21

Copilot AI review requested due to automatic review settings December 18, 2025 22:21

Copilot started reviewing on behalf of overlookmotel December 18, 2025 22:21 View session

Copilot AI reviewed Dec 18, 2025

View reviewed changes

overlookmotel force-pushed the om/12-18-perf_allocator_reduce_time_mutex_lock_is_held_in_fixedsizeallocatorpool_get_ branch from 8633439 to 2df9b9c Compare December 18, 2025 23:02

overlookmotel force-pushed the om/12-18-refactor_allocator_move_nested_function_out_of_fixedsizeallocatorpool_get_ branch from 1f5a828 to 348c622 Compare December 18, 2025 23:02

overlookmotel self-assigned this Dec 18, 2025

overlookmotel mentioned this pull request Dec 18, 2025

docs(linter): fix typo in doc comment #17091

Merged

overlookmotel added the A-linter-plugins Area - Linter JS plugins label Dec 18, 2025

graphite-app bot added the 0-merge Merge with Graphite Merge Queue label Dec 18, 2025

graphite-app bot force-pushed the om/12-18-refactor_allocator_move_nested_function_out_of_fixedsizeallocatorpool_get_ branch from 348c622 to 40a30fe Compare December 18, 2025 23:44

graphite-app bot force-pushed the om/12-18-perf_allocator_reduce_time_mutex_lock_is_held_in_fixedsizeallocatorpool_get_ branch from 2df9b9c to b657bb6 Compare December 18, 2025 23:44

graphite-app bot removed the 0-merge Merge with Graphite Merge Queue label Dec 18, 2025

Base automatically changed from om/12-18-refactor_allocator_move_nested_function_out_of_fixedsizeallocatorpool_get_ to main December 18, 2025 23:50

graphite-app bot merged commit b657bb6 into main Dec 18, 2025
22 checks passed

graphite-app bot deleted the om/12-18-perf_allocator_reduce_time_mutex_lock_is_held_in_fixedsizeallocatorpool_get_ branch December 18, 2025 23:51

Boshen mentioned this pull request Dec 19, 2025

release(crates): oxc v0.104.0 #17096

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Comments

perf(allocator): reduce time `Mutex` lock is held in `FixedSizeAllocatorPool::get`#17079

perf(allocator): reduce time `Mutex` lock is held in `FixedSizeAllocatorPool::get`#17079
graphite-app[bot] merged 1 commit intomainfrom
om/12-18-perf_allocator_reduce_time_mutex_lock_is_held_in_fixedsizeallocatorpool_get_

overlookmotel commented Dec 18, 2025 •

edited

Loading

Uh oh!

overlookmotel commented Dec 18, 2025 •

edited

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

codspeed-hq bot commented Dec 18, 2025 •

edited

Loading

Uh oh!

graphite-app bot commented Dec 18, 2025 •

edited

Loading

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Uh oh!

Comments

Conversation

overlookmotel commented Dec 18, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

overlookmotel commented Dec 18, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

How to use the Graphite Merge Queue

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

codspeed-hq bot commented Dec 18, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

CodSpeed Performance Report

Merging #17079 will not alter performance

Summary

Footnotes

Uh oh!

graphite-app bot commented Dec 18, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Merge activity

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

overlookmotel commented Dec 18, 2025 •

edited

Loading

overlookmotel commented Dec 18, 2025 •

edited

Loading

codspeed-hq bot commented Dec 18, 2025 •

edited

Loading

graphite-app bot commented Dec 18, 2025 •

edited

Loading