diff --git a/doc/api/timers.md b/doc/api/timers.md index 4a903b5f5eef0e..9460028928bba1 100644 --- a/doc/api/timers.md +++ b/doc/api/timers.md @@ -186,7 +186,7 @@ added: v0.0.1 Schedules repeated execution of `callback` every `delay` milliseconds. When `delay` is larger than `2147483647` or less than `1`, the `delay` will be -set to `1`. +set to `1`. Non-integer delays are truncated to an integer. If `callback` is not a function, a [`TypeError`][] will be thrown. @@ -209,7 +209,7 @@ nor of their ordering. The callback will be called as close as possible to the time specified. When `delay` is larger than `2147483647` or less than `1`, the `delay` -will be set to `1`. +will be set to `1`. Non-integer delays are truncated to an integer. If `callback` is not a function, a [`TypeError`][] will be thrown. diff --git a/lib/timers.js b/lib/timers.js index 0937e73c4abd80..14151d6d81d63e 100644 --- a/lib/timers.js +++ b/lib/timers.js @@ -193,10 +193,13 @@ exports._unrefActive = function(item) { // Appends a timer onto the end of an existing timers list, or creates a new // list if one does not already exist for the specified timeout duration. function insert(item, refed, start) { - const msecs = item._idleTimeout; + let msecs = item._idleTimeout; if (msecs < 0 || msecs === undefined) return; + // Truncate so that accuracy of sub-milisecond timers is not assumed. + msecs = Math.trunc(msecs); + item._idleStart = start; // Use an existing list if there is one, otherwise we need to make a new one. @@ -378,7 +381,9 @@ function unenroll(item) { // clearTimeout that makes it clear that the list should not be deleted. // That function could then be used by http and other similar modules. if (item[kRefed]) { - const list = lists[item._idleTimeout]; + // Compliment truncation during insert(). + const msecs = Math.trunc(item._idleTimeout); + const list = lists[msecs]; if (list !== undefined && L.isEmpty(list)) { debug('unenroll: list empty'); queue.removeAt(list.priorityQueuePosition); diff --git a/test/parallel/test-timers-non-integer-delay.js b/test/parallel/test-timers-non-integer-delay.js index 017ef28d0f86ef..a57922e3c78fe3 100644 --- a/test/parallel/test-timers-non-integer-delay.js +++ b/test/parallel/test-timers-non-integer-delay.js @@ -21,6 +21,7 @@ 'use strict'; const common = require('../common'); +const assert = require('assert'); /* * This test makes sure that non-integer timer delays do not make the process @@ -47,3 +48,37 @@ const interval = setInterval(common.mustCall(() => { process.exit(0); } }, N), TIMEOUT_DELAY); + +// Test non-integer delay ordering +{ + const ordering = []; + + setTimeout(common.mustCall(() => { + ordering.push(1); + }), 1); + + setTimeout(common.mustCall(() => { + ordering.push(2); + }), 1.8); + + setTimeout(common.mustCall(() => { + ordering.push(3); + }), 1.1); + + setTimeout(common.mustCall(() => { + ordering.push(4); + }), 1); + + setTimeout(common.mustCall(() => { + const expected = [1, 2, 3, 4]; + + assert.deepStrictEqual( + ordering, + expected, + `Non-integer delay ordering should be ${expected}, but got ${ordering}` + ); + + // 2 should always be last of these delays due to ordering guarentees by + // the implementation. + }), 2); +}