From 9c9f1a32954a310b0fe2ffda78545d59a2c56bbe Mon Sep 17 00:00:00 2001
From: Brian Vaughn <bvaughn@fb.com>
Date: Wed, 23 Sep 2020 15:32:05 -0400
Subject: [PATCH] Moved Profiler commit-phase bubbling into work loop

This enables us to only track a single item in the stack and requires less ugly coupling between the work loop and commit work.
---
 .../src/ReactFiberCommitWork.new.js           | 15 ----------
 .../src/ReactFiberWorkLoop.new.js             | 29 ++++++++++++-------
 2 files changed, 18 insertions(+), 26 deletions(-)

diff --git a/packages/react-reconciler/src/ReactFiberCommitWork.new.js b/packages/react-reconciler/src/ReactFiberCommitWork.new.js
index 615ea8ac3edf3..2079e464d34eb 100644
--- a/packages/react-reconciler/src/ReactFiberCommitWork.new.js
+++ b/packages/react-reconciler/src/ReactFiberCommitWork.new.js
@@ -120,7 +120,6 @@ import {
   resolveRetryWakeable,
   markCommitTimeOfFallback,
   schedulePassiveEffectCallback,
-  penultimateProfilerOnStack,
 } from './ReactFiberWorkLoop.new';
 import {
   NoFlags as NoHookEffect,
@@ -424,13 +423,6 @@ function commitProfilerPassiveEffect(
             );
           }
         }
-
-        // Bubble times to the next nearest ancestor Profiler.
-        // After we process that Profiler, we'll bubble further up.
-        if (penultimateProfilerOnStack !== null) {
-          const stateNode = penultimateProfilerOnStack.stateNode;
-          stateNode.passiveEffectDuration += passiveEffectDuration;
-        }
         break;
       }
       default:
@@ -727,13 +719,6 @@ function commitLifeCycles(
               );
             }
           }
-
-          // Propagate layout effect durations to the next nearest Profiler ancestor.
-          // Do not reset these values until the next render so DevTools has a chance to read them first.
-          if (penultimateProfilerOnStack !== null) {
-            const stateNode = penultimateProfilerOnStack.stateNode;
-            stateNode.effectDuration += effectDuration;
-          }
         }
       }
       return;
diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.new.js b/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
index 1d3ccfecabb28..039d87e81a4e7 100644
--- a/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
+++ b/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
@@ -370,7 +370,6 @@ let shouldFireAfterActiveInstanceBlur: boolean = false;
 
 // Used to avoid traversing the return path to find the nearest Profiler ancestor during commit.
 let nearestProfilerOnStack: Fiber | null = null;
-export let penultimateProfilerOnStack: Fiber | null = null;
 
 export function getWorkInProgressRoot(): FiberRoot | null {
   return workInProgressRoot;
@@ -2367,11 +2366,10 @@ function commitLayoutEffects(
 ) {
   let fiber = firstChild;
   while (fiber !== null) {
-    let prevPenultimateProfiler = null;
+    let prevProfilerOnStack = null;
     if (enableProfilerTimer && enableProfilerCommitHooks) {
       if (fiber.tag === Profiler) {
-        prevPenultimateProfiler = penultimateProfilerOnStack;
-        penultimateProfilerOnStack = nearestProfilerOnStack;
+        prevProfilerOnStack = nearestProfilerOnStack;
         nearestProfilerOnStack = fiber;
       }
     }
@@ -2408,8 +2406,13 @@ function commitLayoutEffects(
 
     if (enableProfilerTimer && enableProfilerCommitHooks) {
       if (fiber.tag === Profiler) {
-        nearestProfilerOnStack = penultimateProfilerOnStack;
-        penultimateProfilerOnStack = prevPenultimateProfiler;
+        // Propagate layout effect durations to the next nearest Profiler ancestor.
+        // Do not reset these values until the next render so DevTools has a chance to read them first.
+        if (prevProfilerOnStack !== null) {
+          prevProfilerOnStack.stateNode.effectDuration += fiber.stateNode.effectDuration;
+        }
+
+        nearestProfilerOnStack = prevProfilerOnStack;
       }
     }
 
@@ -2474,11 +2477,10 @@ export function flushPassiveEffects(): boolean {
 function flushPassiveMountEffects(root, firstChild: Fiber): void {
   let fiber = firstChild;
   while (fiber !== null) {
-    let prevPenultimateProfiler = null;
+    let prevProfilerOnStack = null;
     if (enableProfilerTimer && enableProfilerCommitHooks) {
       if (fiber.tag === Profiler) {
-        prevPenultimateProfiler = penultimateProfilerOnStack;
-        penultimateProfilerOnStack = nearestProfilerOnStack;
+        prevProfilerOnStack = nearestProfilerOnStack;
         nearestProfilerOnStack = fiber;
       }
     }
@@ -2515,8 +2517,13 @@ function flushPassiveMountEffects(root, firstChild: Fiber): void {
 
     if (enableProfilerTimer && enableProfilerCommitHooks) {
       if (fiber.tag === Profiler) {
-        nearestProfilerOnStack = penultimateProfilerOnStack;
-        penultimateProfilerOnStack = prevPenultimateProfiler;
+        // Bubble times to the next nearest ancestor Profiler.
+        // After we process that Profiler, we'll bubble further up.
+        if (prevProfilerOnStack !== null) {
+          prevProfilerOnStack.stateNode.passiveEffectDuration += fiber.stateNode.passiveEffectDuration;
+        }
+
+        nearestProfilerOnStack = prevProfilerOnStack;
       }
     }