timers: do less work in insert

Most of the code in insert is only applicable to scheduling
non-timers or re-scheduling timers. We can skip most of it
in the case of setTimeout, setInterval & setUnrefTimeout.
PR-URL: #27345
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: apapirovski

lib/internal/timers.js

@@ -155,7 +155,7 @@ function initAsyncResource(resource, type) {
 
 // Timer constructor function.
 // The entire prototype is defined in lib/timers.js
-functionTimeout(callback,after,args,isRepeat){
+functionTimeout(callback,after,args,isRepeat,isRefed){
 after*=1;// Coalesce to number or NaN
 if(!(after>=1&&after<=TIMEOUT_MAX)){
 if(after>TIMEOUT_MAX){
@@ -179,7 +179,9 @@ function Timeout(callback, after, args, isRepeat) {
 this._repeat=isRepeat ? after : null;
 this._destroyed=false;
 
-this[kRefed]=null;
+if(isRefed)
+incRefCount();
+this[kRefed]=isRefed;
 
 initAsyncResource(this,'Timeout');
 }
@@ -295,27 +297,43 @@ function decRefCount() {
 // Schedule or re-schedule a timer.
 // The item must have been enroll()'d first.
 functionactive(item){
-insert(item,true,getLibuvNow());
+insertGuarded(item,true);
 }
 
 // Internal APIs that need timeouts should use `unrefActive()` instead of
 // `active()` so that they do not unnecessarily keep the process open.
 functionunrefActive(item){
-insert(item,false,getLibuvNow());
+insertGuarded(item,false);
 }
 
 // The underlying logic for scheduling or re-scheduling a timer.
 //
 // 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.
-functioninsert(item,refed,start){
-letmsecs=item._idleTimeout;
+functioninsertGuarded(item,refed,start){
+constmsecs=item._idleTimeout;
 if(msecs<0||msecs===undefined)
 return;
 
-// Truncate so that accuracy of sub-millisecond timers is not assumed.
-msecs=MathTrunc(msecs);
+insert(item,msecs,start);
+
+if(!item[async_id_symbol]||item._destroyed){
+item._destroyed=false;
+initAsyncResource(item,'Timeout');
+}
+
+if(refed===!item[kRefed]){
+if(refed)
+incRefCount();
+else
+decRefCount();
+}
+item[kRefed]=refed;
+}
 
+functioninsert(item,msecs,start=getLibuvNow()){
+// Truncate so that accuracy of sub-milisecond timers is not assumed.
+msecs=MathTrunc(msecs);
 item._idleStart=start;
 
 // Use an existing list if there is one, otherwise we need to make a new one.
@@ -332,19 +350,6 @@ function insert(item, refed, start) {
 }
 }
 
-if(!item[async_id_symbol]||item._destroyed){
-item._destroyed=false;
-initAsyncResource(item,'Timeout');
-}
-
-if(refed===!item[kRefed]){
-if(refed)
-incRefCount();
-else
-decRefCount();
-}
-item[kRefed]=refed;
-
 L.append(list,item);
 }
 
@@ -354,8 +359,8 @@ function setUnrefTimeout(callback, after) {
 thrownewERR_INVALID_CALLBACK(callback);
 }
 
-consttimer=newTimeout(callback,after,undefined,false);
-unrefActive(timer);
+consttimer=newTimeout(callback,after,undefined,false,false);
+insert(timer,timer._idleTimeout);
 
 returntimer;
 }
@@ -540,16 +545,14 @@ function getTimerCallbacks(runNextTicks) {
 }finally{
 if(timer._repeat&&timer._idleTimeout!==-1){
 timer._idleTimeout=timer._repeat;
-if(start===undefined)
-start=getLibuvNow();
-insert(timer,timer[kRefed],start);
+insert(timer,timer._idleTimeout,start);
 }elseif(!timer._idleNext&&!timer._idlePrev){
 if(timer[kRefed])
 refCount--;
 timer[kRefed]=null;
 
 if(destroyHooksExist()&&!timer._destroyed){
-emitDestroy(timer[async_id_symbol]);
+emitDestroy(asyncId);
 }
 timer._destroyed=true;
 }
@@ -598,6 +601,7 @@ module.exports = {
 },
  active,
  unrefActive,
+ insert,
  timerListMap,
  timerListQueue,
  decRefCount,

lib/timers.js

@@ -46,7 +46,8 @@ const {
  timerListQueue,
  immediateQueue,
  active,
- unrefActive
+ unrefActive,
+ insert
 }=require('internal/timers');
 const{
 promisify: {custom: customPromisify},
@@ -142,16 +143,17 @@ function setTimeout(callback, after, arg1, arg2, arg3) {
 break;
 }
 
-consttimeout=newTimeout(callback,after,args,false);
-active(timeout);
+consttimeout=newTimeout(callback,after,args,false,true);
+insert(timeout,timeout._idleTimeout);
 
 returntimeout;
 }
 
 setTimeout[customPromisify]=function(after,value){
 constargs=value!==undefined ? [value] : value;
 returnnewPromise((resolve)=>{
-active(newTimeout(resolve,after,args,false));
+consttimeout=newTimeout(resolve,after,args,false,true);
+insert(timeout,timeout._idleTimeout);
 });
 };
 
@@ -188,8 +190,8 @@ function setInterval(callback, repeat, arg1, arg2, arg3) {
 break;
 }
 
-consttimeout=newTimeout(callback,repeat,args,true);
-active(timeout);
+consttimeout=newTimeout(callback,repeat,args,true,true);
+insert(timeout,timeout._idleTimeout);
 
 returntimeout;
 }