timers: prevent event loop blocking

When an interval takes as long or longer to run as its timeout setting
and the roundtrip from rearm() to its deferal takes exactly 1ms, that
interval can then block the event loop. This is an edge case of another
recently fixed bug (which in itself was an edge case).

PR-URL: https://github.com/nodejs/node/pull/18486
Refs: https://github.com/nodejs/node/pull/15072
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
This commit is contained in:
Anatoli Papirovski 2018-01-31 13:37:01 -05:00
parent d7894f3969
commit 47a984ada0
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2 changed files with 8 additions and 1 deletions

View File

@ -238,7 +238,7 @@ TimerWrap.prototype[kOnTimeout] = function listOnTimeout(now) {
// This happens if there are more timers scheduled for later in the list.
if (diff < msecs) {
var timeRemaining = msecs - (TimerWrap.now() - timer._idleStart);
if (timeRemaining < 0) {
if (timeRemaining <= 0) {
timeRemaining = 1;
}
this.start(timeRemaining);

View File

@ -9,9 +9,16 @@ const t = setInterval(() => {
cntr++;
if (cntr === 1) {
common.busyLoop(100);
// ensure that the event loop passes before the second interval
setImmediate(() => assert.strictEqual(cntr, 1));
first = Timer.now();
} else if (cntr === 2) {
assert(Timer.now() - first < 100);
clearInterval(t);
}
}, 100);
const t2 = setInterval(() => {
if (cntr === 2) {
clearInterval(t2);
}
}, 100);