timers: re-enter C++ less frequently

Pass in Timer.now() as an argument of kOnTimeout instead of always
re-entering C++ to get it. Also don't constantly call Timer.now()
from ontimeout, even when it isn't needed. Improves performance
on our pooled benchmark by upwards of 40%.

PR-URL: https://github.com/nodejs/node/pull/18486
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/lib/timers.js b/lib/timers.js
index a91de76d7f..83affee7d8 100644
--- a/lib/timers.js
+++ b/lib/timers.js
@@ -223,13 +223,11 @@ function TimersList(msecs, unrefed) {
 
 // adds listOnTimeout to the C++ object prototype, as
 // V8 would not inline it otherwise.
-TimerWrap.prototype[kOnTimeout] = function listOnTimeout() {
+TimerWrap.prototype[kOnTimeout] = function listOnTimeout(now) {
   var list = this._list;
   var msecs = list.msecs;
 
   debug('timeout callback %d', msecs);
-
-  var now = TimerWrap.now();
   debug('now: %d', now);
 
   var diff, timer;
@@ -430,11 +428,12 @@ setTimeout[internalUtil.promisify.custom] = function(after, value) {
 exports.setTimeout = setTimeout;
 
 
-function ontimeout(timer) {
+function ontimeout(timer, start) {
   var args = timer._timerArgs;
   if (typeof timer._onTimeout !== 'function')
     return promiseResolve(timer._onTimeout, args[0]);
-  const start = TimerWrap.now();
+  if (start === undefined && timer._repeat)
+    start = TimerWrap.now();
   if (!args)
     timer._onTimeout();
   else
@@ -518,11 +517,11 @@ exports.clearInterval = function(timer) {
 };
 
 
-function unrefdHandle() {
+function unrefdHandle(now) {
   try {
     // Don't attempt to call the callback if it is not a function.
     if (typeof this.owner._onTimeout === 'function') {
-      ontimeout(this.owner);
+      ontimeout(this.owner, now);
     }
   } finally {
     // Make sure we clean up if the callback is no longer a function