From d673dd1b7b3f189cbaf688ed368939f071135d89 Mon Sep 17 00:00:00 2001
From: ganhaobo <ganhaobo@meicai.cn>
Date: Wed, 18 Aug 2021 22:19:43 +0800
Subject: [PATCH] perf(scheduler): remove unnecessary statement

---
 .../runtime-core/__tests__/scheduler.spec.ts  |  6 +++--
 packages/runtime-core/src/renderer.ts         |  2 +-
 packages/runtime-core/src/scheduler.ts        | 27 ++++++-------------
 3 files changed, 13 insertions(+), 22 deletions(-)

diff --git a/packages/runtime-core/__tests__/scheduler.spec.ts b/packages/runtime-core/__tests__/scheduler.spec.ts
index 750a2ed19b5..92b243e2ef4 100644
--- a/packages/runtime-core/__tests__/scheduler.spec.ts
+++ b/packages/runtime-core/__tests__/scheduler.spec.ts
@@ -211,6 +211,8 @@ describe('scheduler', () => {
 
     it('preFlushCb inside queueJob', async () => {
       const calls: string[] = []
+
+      // job1.allowRecurse is undefined, so it equal to false
       const job1 = () => {
         // the only case where a pre-flush cb can be queued inside a job is
         // when updating the props of a child component. This is handled
@@ -218,12 +220,12 @@ describe('scheduler', () => {
         // cb triggers (#1763)
         queuePreFlushCb(cb1)
         queuePreFlushCb(cb2)
-        flushPreFlushCbs(undefined, job1)
+        flushPreFlushCbs()
         calls.push('job1')
       }
       const cb1 = () => {
         calls.push('cb1')
-        // a cb triggers its parent job, which should be skipped
+        // with job1.allowRecurse false,it won't be added into queue again
         queueJob(job1)
       }
       const cb2 = () => {
diff --git a/packages/runtime-core/src/renderer.ts b/packages/runtime-core/src/renderer.ts
index 76848cb52f3..233369c9f70 100644
--- a/packages/runtime-core/src/renderer.ts
+++ b/packages/runtime-core/src/renderer.ts
@@ -1593,7 +1593,7 @@ function baseCreateRenderer(
     pauseTracking()
     // props update may have triggered pre-flush watchers.
     // flush them before the render update.
-    flushPreFlushCbs(undefined, instance.update)
+    flushPreFlushCbs()
     resetTracking()
   }
 
diff --git a/packages/runtime-core/src/scheduler.ts b/packages/runtime-core/src/scheduler.ts
index 333125d578d..63d45e1b1f2 100644
--- a/packages/runtime-core/src/scheduler.ts
+++ b/packages/runtime-core/src/scheduler.ts
@@ -50,8 +50,6 @@ let postFlushIndex = 0
 const resolvedPromise: Promise<any> = Promise.resolve()
 let currentFlushPromise: Promise<void> | null = null
 
-let currentPreFlushParentJob: SchedulerJob | null = null
-
 const RECURSION_LIMIT = 100
 type CountMap = Map<SchedulerJob, number>
 
@@ -89,12 +87,11 @@ export function queueJob(job: SchedulerJob) {
   // allow it recursively trigger itself - it is the user's responsibility to
   // ensure it doesn't end up in an infinite loop.
   if (
-    (!queue.length ||
-      !queue.includes(
-        job,
-        isFlushing && job.allowRecurse ? flushIndex + 1 : flushIndex
-      )) &&
-    job !== currentPreFlushParentJob
+    !queue.length ||
+    !queue.includes(
+      job,
+      isFlushing && job.allowRecurse ? flushIndex + 1 : flushIndex
+    )
   ) {
     if (job.id == null) {
       queue.push(job)
@@ -128,10 +125,7 @@ function queueCb(
   if (!isArray(cb)) {
     if (
       !activeQueue ||
-      !activeQueue.includes(
-        cb,
-        cb.allowRecurse ? index + 1 : index
-      )
+      !activeQueue.includes(cb, cb.allowRecurse ? index + 1 : index)
     ) {
       pendingQueue.push(cb)
     }
@@ -152,12 +146,8 @@ export function queuePostFlushCb(cb: SchedulerJobs) {
   queueCb(cb, activePostFlushCbs, pendingPostFlushCbs, postFlushIndex)
 }
 
-export function flushPreFlushCbs(
-  seen?: CountMap,
-  parentJob: SchedulerJob | null = null
-) {
+export function flushPreFlushCbs(seen?: CountMap) {
   if (pendingPreFlushCbs.length) {
-    currentPreFlushParentJob = parentJob
     activePreFlushCbs = [...new Set(pendingPreFlushCbs)]
     pendingPreFlushCbs.length = 0
     if (__DEV__) {
@@ -178,9 +168,8 @@ export function flushPreFlushCbs(
     }
     activePreFlushCbs = null
     preFlushIndex = 0
-    currentPreFlushParentJob = null
     // recursively flush until it drains
-    flushPreFlushCbs(seen, parentJob)
+    flushPreFlushCbs(seen)
   }
 }