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| author | Bartek Iwańczuk <biwanczuk@gmail.com> | 2023-06-14 16:21:06 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-06-14 16:21:06 +0200 |
| commit | 5ef225853c0f81ba0a7d1ce888ab3b2d283eae0a (patch) | |
| tree | 169c5e4f2f428bf3782351c5b9563febaa100dfd /runtime/js/99_main.js | |
| parent | 691ef2cc6a1144d17d6ffbc7f4ed88ba424ec3c0 (diff) | |
perf: don't run microtask checkpoint if macrotask callback did no work (#19492)
Most of the time there's no firing timers, nor pending promise
rejections, so it's wasteful to run microtask checkpoint
additionally twice on each tick of the event loop.
Closes https://github.com/denoland/deno/issues/18871
Ref https://github.com/denoland/deno/issues/19451
Diffstat (limited to 'runtime/js/99_main.js')
| -rw-r--r-- | runtime/js/99_main.js | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/runtime/js/99_main.js b/runtime/js/99_main.js index 8fd9a6bd9..511368141 100644 --- a/runtime/js/99_main.js +++ b/runtime/js/99_main.js @@ -351,6 +351,12 @@ function promiseRejectCallback(type, promise, reason) { } function promiseRejectMacrotaskCallback() { + // We have no work to do, tell the runtime that we don't + // need to perform microtask checkpoint. + if (pendingRejections.length === 0) { + return undefined; + } + while (pendingRejections.length > 0) { const promise = ArrayPrototypeShift(pendingRejections); const hasPendingException = ops.op_has_pending_promise_rejection( |