perf(testing): share tokio runtime across fixture tests by Boshen · Pull Request #8567 · rolldown/rolldown

Boshen · 2026-03-06T14:51:24Z

Summary

Each of the ~1,682 fixture tests creates a new tokio::runtime::Runtime via Runtime::new().unwrap().block_on(...). This replaces that with a shared static runtime using OnceLock<Runtime>, eliminating repeated thread pool creation/teardown overhead.

Results (`cargo test --workspace --exclude rolldown_binding`)

	Wall clock	User CPU	System CPU
Baseline (per-test runtime)	33.5s	133.5s	65.2s
Shared runtime	25.3s	116.1s	43.0s
Improvement	-8.2s (24%)	-17.4s	-22.2s

The shared runtime saves ~8 seconds (24% faster) wall-clock time, with a notable reduction in system CPU time (65s → 43s) from eliminating repeated thread pool creation/teardown.

🤖 Generated with Claude Code

netlify · 2026-03-06T14:51:42Z

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Boshen · 2026-03-06T14:54:15Z

Merge activity

Mar 6, 2:54 PM UTC: The merge label 'graphite: merge-when-ready' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Mar 7, 2:48 AM UTC: Boshen added this pull request to the Graphite merge queue.
Mar 7, 2:58 AM UTC: Merged by the Graphite merge queue.

Copilot

Pull request overview

This PR improves test-suite performance in rolldown_testing by avoiding per-test Tokio runtime creation and instead reusing a single static runtime across all fixture integration tests.

Changes:

Introduces a shared static tokio::runtime::Runtime via OnceLock.
Updates fixture integration test runners to execute async work via the shared runtime.

crates/rolldown_testing/src/fixture.rs

github-actions · 2026-03-06T15:10:04Z

Benchmarks Rust

target: main(290a715)
pr: perf/share-tokio-runtime-fixture-tests(4732a16)

group                                                        pr                                     target
-----                                                        --                                     ------
bundle/bundle@multi-duplicated-top-level-symbol              1.12     90.1±3.52ms        ? ?/sec    1.00     80.7±2.53ms        ? ?/sec
bundle/bundle@multi-duplicated-top-level-symbol-sourcemap    1.14     97.8±2.63ms        ? ?/sec    1.00     85.5±1.58ms        ? ?/sec
bundle/bundle@rome_ts                                        1.12    183.1±3.72ms        ? ?/sec    1.00    162.9±7.43ms        ? ?/sec
bundle/bundle@rome_ts-sourcemap                              1.13    202.8±3.97ms        ? ?/sec    1.00    180.2±4.67ms        ? ?/sec
bundle/bundle@threejs                                        1.11     81.5±2.83ms        ? ?/sec    1.00     73.3±2.86ms        ? ?/sec
bundle/bundle@threejs-sourcemap                              1.13     89.3±2.38ms        ? ?/sec    1.00     79.1±1.96ms        ? ?/sec
bundle/bundle@threejs10x                                     1.03   779.2±17.49ms        ? ?/sec    1.00    759.9±7.01ms        ? ?/sec
bundle/bundle@threejs10x-sourcemap                           1.01    876.8±7.55ms        ? ?/sec    1.00    868.3±6.63ms        ? ?/sec
scan/scan@rome_ts                                            1.01     77.8±1.43ms        ? ?/sec    1.00     76.6±1.61ms        ? ?/sec
scan/scan@threejs                                            1.01     27.5±0.47ms        ? ?/sec    1.00     27.2±0.47ms        ? ?/sec
scan/scan@threejs10x                                         1.00    267.0±4.26ms        ? ?/sec    1.00    267.5±4.46ms        ? ?/sec

Copilot · 2026-03-06T15:13:23Z

@hyf0 I've opened a new pull request, #8568, to work on those changes. Once the pull request is ready, I'll request review from you.

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Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

crates/rolldown_testing/src/integration_test.rs

Copilot

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

crates/rolldown_testing/src/integration_test.rs

Copilot · 2026-03-07T01:55:40Z

@hyf0 I've opened a new pull request, #8569, to work on those changes. Once the pull request is ready, I'll request review from you.

## Summary Each of the ~1,682 fixture tests creates a new `tokio::runtime::Runtime` via `Runtime::new().unwrap().block_on(...)`. This replaces that with a shared static runtime using `OnceLock<Runtime>`, eliminating repeated thread pool creation/teardown overhead. ## Results (`cargo test --workspace --exclude rolldown_binding`) | | Wall clock | User CPU | System CPU | |---|---|---|---| | **Baseline** (per-test runtime) | 33.5s | 133.5s | 65.2s | | **Shared runtime** | 25.3s | 116.1s | 43.0s | | **Improvement** | **-8.2s (24%)** | -17.4s | -22.2s | The shared runtime saves ~8 seconds (24% faster) wall-clock time, with a notable reduction in system CPU time (65s → 43s) from eliminating repeated thread pool creation/teardown. 🤖 Generated with [Claude Code](https://claude.com/claude-code)

@hyf0

## [1.0.0-rc.8] - 2026-03-09 ### 🚀 Features - watch: enable full functional fs watcher in wasm (#8575) by @hyf0 - watch: expose debounce related options (#8572) by @hyf0 ### 🐛 Bug Fixes - detect new URL(…, import.meta.url) with no-sub template literal (#8565) by @char - devtools: trace dynamic imports in devtools (#8581) by @cal-gooo - watch: rebuild when a previously missing file is created (#8562) by @hyf0-agent - watch: filter out Access events to prevent infinite rebuild loop on Linux (#8557) by @hyf0-agent ### 🚜 Refactor - watch: remove auto watch for fail imports (#8585) by @hyf0 - fs_watcher: unify the way of constructing watcher (#8571) by @hyf0 - cli: migrate CLI to CAC (#8551) by @h-a-n-a - switch asset module support from hard-code to builtin plugin (#8546) by @hyf0 ### 📚 Documentation - fix subject-verb agreement in why-bundlers.md (#8591) by @brandonzylstra - maintenance: align release and canary workflow guide (#8538) by @minsoo-web - add `format` option to directives example config (#8590) by @shulaoda - fix: change twitter to x logo in team (#8552) by @mdong1909 - correct composable filter support explanation (#8550) by @sapphi-red ### ⚡ Performance - testing: share tokio runtime across fixture tests (#8567) by @Boshen ### 🧪 Testing - hmr: fix infinite loop in dev server test retry logic (#8576) by @hyf0-agent - cli: add more cli-e2e test cases (#8548) by @h-a-n-a ### ⚙️ Miscellaneous Tasks - docs: update in-depth/directives for `output.strict` option (#8535) by @minsoo-web - add PNPM_HOME Dev Drive mapping to Windows CI workflows (#8589) by @Boshen - deps: update github-actions (#8588) by @renovate[bot] - move Windows cargo target dir to Dev Drive (#8586) by @Boshen - optimize cache keys to fix race conditions and reduce usage (#8578) by @Boshen - remove WASI build & test pipeline (#8580) by @Boshen - remove unnecessary submodule checkouts (#8577) by @Boshen - use Dev Drive for Windows CI jobs (#8574) by @Boshen - skip redundant native binding build for browser and remove standalone job (#8573) by @Boshen - parallelize Node tests on ubuntu, single Node 24 on macOS/windows (#8570) by @Boshen - docs: bump @voidzero-dev/vitepress-theme to 4.8.0 (#8558) by @crusty-voidzero - dedupe type-check from dev server workflow (#8554) by @Boshen ### ❤️ New Contributors * @brandonzylstra made their first contribution in [#8591](#8591) * @char made their first contribution in [#8565](#8565) * @cal-gooo made their first contribution in [#8581](#8581) * @hyf0-agent made their first contribution in [#8562](#8562) * @h-a-n-a made their first contribution in [#8551](#8551) Co-authored-by: shulaoda <165626830+shulaoda@users.noreply.github.com>

Copilot AI review requested due to automatic review settings March 6, 2026 14:51

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fix: explicitly close DevEngine to prevent coordinator task leaks under shared runtime #8568

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Copilot AI mentioned this pull request Mar 7, 2026

fix: prevent deadlock in DevEngine::close() by scoping bundler lock #8569

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graphite-app bot force-pushed the perf/share-tokio-runtime-fixture-tests branch from 9d09474 to 4732a16 Compare March 7, 2026 02:48

graphite-app bot merged commit 4732a16 into main Mar 7, 2026
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graphite-app bot deleted the perf/share-tokio-runtime-fixture-tests branch March 7, 2026 02:58

github-actions bot mentioned this pull request Mar 9, 2026

release: v1.0.0-rc.8 #8592

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perf(testing): share tokio runtime across fixture tests#8567
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Boshen commented Mar 6, 2026

Summary

Results (cargo test --workspace --exclude rolldown_binding)

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