From 6585b161ba662bd6199e0428341cd3f6af86957a Mon Sep 17 00:00:00 2001 From: Andrey Pechkurov Date: Sat, 3 Oct 2020 16:57:35 +0300 Subject: [PATCH] doc: improve eventLoopUtilization documentation PR-URL: https://github.com/nodejs/node/pull/35479 Reviewed-By: Anna Henningsen Reviewed-By: Luigi Pinca Reviewed-By: James M Snell Reviewed-By: Harshitha K P Reviewed-By: Colin Ihrig Reviewed-By: Daijiro Wachi --- doc/api/perf_hooks.md | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/doc/api/perf_hooks.md b/doc/api/perf_hooks.md index d67bc8436f9ac4..6b14a23c474a26 100644 --- a/doc/api/perf_hooks.md +++ b/doc/api/perf_hooks.md @@ -58,9 +58,10 @@ Performance Timeline. If `name` is provided, removes only the named mark. added: v14.10.0 --> -* `utilization1` {Object} The result of a previous call to `eventLoopUtilization()` -* `utilization2` {Object} The result of a previous call to `eventLoopUtilization()` - prior to `util1` +* `utilization1` {Object} The result of a previous call to + `eventLoopUtilization()`. +* `utilization2` {Object} The result of a previous call to + `eventLoopUtilization()` prior to `utilization1`. * Returns {Object} * `idle` {number} * `active` {number} @@ -70,9 +71,9 @@ The `eventLoopUtilization()` method returns an object that contains the cumulative duration of time the event loop has been both idle and active as a high resolution milliseconds timer. The `utilization` value is the calculated Event Loop Utilization (ELU). If bootstrapping has not yet finished, the -properties have the value of 0. +properties have the value of `0`. -`utilization1` and `utilization2` are optional parameters. +Both `utilization1` and `utilization2` are optional parameters. If `utilization1` is passed, then the delta between the current call's `active` and `idle` times, as well as the corresponding `utilization` value are @@ -102,8 +103,8 @@ setImmediate(() => { ``` Although the CPU is mostly idle while running this script, the value of -`utilization` is 1. This is because the call to [`child_process.spawnSync()`][] -blocks the event loop from proceeding. +`utilization` is `1`. This is because the call to +[`child_process.spawnSync()`][] blocks the event loop from proceeding. Passing in a user-defined object instead of the result of a previous call to `eventLoopUtilization()` will lead to undefined behavior. The return values