Add enableSyncDefaultUpdates implementation

Author: rickhanlonii

packages/react-reconciler/src/ReactFiberLane.new.js

@@ -47,15 +47,15 @@ export const NoLane: Lane = /*                          */ 0b0000000000000000000
 
 export const SyncLane: Lane = /*                        */ 0b0000000000000000000000000000001;
 
-const InputContinuousHydrationLane: Lane = /*           */ 0b0000000000000000000000000000010;
+export const InputContinuousHydrationLane: Lane = /*    */ 0b0000000000000000000000000000010;
 export const InputContinuousLane: Lanes = /*            */ 0b0000000000000000000000000000100;
 
 export const DefaultHydrationLane: Lane = /*            */ 0b0000000000000000000000000001000;
 export const DefaultLane: Lanes = /*                    */ 0b0000000000000000000000000010000;
 
 const TransitionHydrationLane: Lane = /*                */ 0b0000000000000000000000000100000;
 const TransitionLanes: Lanes = /*                       */ 0b0000000001111111111111111000000;
-const TransitionLane1: Lane = /*                        */ 0b0000000000000000000000001000000;
+export const TransitionLane1: Lane = /*                 */ 0b0000000000000000000000001000000;
 const TransitionLane2: Lane = /*                        */ 0b0000000000000000000000010000000;
 const TransitionLane3: Lane = /*                        */ 0b0000000000000000000000100000000;
 const TransitionLane4: Lane = /*                        */ 0b0000000000000000000001000000000;

packages/react-reconciler/src/ReactFiberLane.old.js

@@ -47,15 +47,15 @@ export const NoLane: Lane = /*                          */ 0b0000000000000000000
 
 export const SyncLane: Lane = /*                        */ 0b0000000000000000000000000000001;
 
-const InputContinuousHydrationLane: Lane = /*           */ 0b0000000000000000000000000000010;
+export const InputContinuousHydrationLane: Lane = /*    */ 0b0000000000000000000000000000010;
 export const InputContinuousLane: Lanes = /*            */ 0b0000000000000000000000000000100;
 
 export const DefaultHydrationLane: Lane = /*            */ 0b0000000000000000000000000001000;
 export const DefaultLane: Lanes = /*                    */ 0b0000000000000000000000000010000;
 
 const TransitionHydrationLane: Lane = /*                */ 0b0000000000000000000000000100000;
 const TransitionLanes: Lanes = /*                       */ 0b0000000001111111111111111000000;
-const TransitionLane1: Lane = /*                        */ 0b0000000000000000000000001000000;
+export const TransitionLane1: Lane = /*                 */ 0b0000000000000000000000001000000;
 const TransitionLane2: Lane = /*                        */ 0b0000000000000000000000010000000;
 const TransitionLane3: Lane = /*                        */ 0b0000000000000000000000100000000;
 const TransitionLane4: Lane = /*                        */ 0b0000000000000000000001000000000;

packages/react-reconciler/src/ReactFiberWorkLoop.new.js

@@ -32,6 +32,7 @@ import {
   disableSchedulerTimeoutInWorkLoop,
   enableStrictEffects,
   skipUnmountedBoundaries,
+  enableSyncDefaultUpdates,
 } from 'shared/ReactFeatureFlags';
 import ReactSharedInternals from 'shared/ReactSharedInternals';
 import invariant from 'shared/invariant';
@@ -137,6 +138,8 @@ import {
   NoLanes,
   NoLane,
   SyncLane,
+  DefaultLane,
+  DefaultHydrationLane,
   NoTimestamp,
   claimNextTransitionLane,
   claimNextRetryLane,
@@ -159,6 +162,8 @@ import {
   markRootFinished,
   areLanesExpired,
   getHighestPriorityLane,
+  InputContinuousLane,
+  InputContinuousHydrationLane,
 } from './ReactFiberLane.new';
 import {
   DiscreteEventPriority,
@@ -426,6 +431,13 @@ export function requestUpdateLane(fiber: Fiber): Lane {
   // TODO: Move this type conversion to the event priority module.
   const updateLane: Lane = (getCurrentUpdatePriority(): any);
   if (updateLane !== NoLane) {
+    if (
+      enableSyncDefaultUpdates &&
+      (updateLane === InputContinuousLane ||
+        updateLane === InputContinuousHydrationLane)
+    ) {
+      return DefaultLane;
+    }
     return updateLane;
   }
 
@@ -682,7 +694,16 @@ function ensureRootIsScheduled(root: FiberRoot, currentTime: number) {
 
   // Schedule a new callback.
   let newCallbackNode;
-  if (newCallbackPriority === SyncLane) {
+  if (
+    enableSyncDefaultUpdates &&
+    (newCallbackPriority === DefaultLane ||
+      newCallbackPriority === DefaultHydrationLane)
+  ) {
+    newCallbackNode = scheduleCallback(
+      ImmediateSchedulerPriority,
+      performSyncWorkOnRoot.bind(null, root),
+    );
+  } else if (newCallbackPriority === SyncLane) {
     // Special case: Sync React callbacks are scheduled on a special
     // internal queue
     scheduleSyncCallback(performSyncWorkOnRoot.bind(null, root));
@@ -1017,7 +1038,11 @@ function performSyncWorkOnRoot(root) {
   const finishedWork: Fiber = (root.current.alternate: any);
   root.finishedWork = finishedWork;
   root.finishedLanes = lanes;
-  commitRoot(root);
+  if (enableSyncDefaultUpdates && includesSomeLane(lanes, DefaultLane)) {
+    finishConcurrentRender(root, exitStatus, lanes);
+  } else {
+    commitRoot(root);
+  }
 
   // Before exiting, make sure there's a callback scheduled for the next
   // pending level.

packages/react-reconciler/src/ReactFiberWorkLoop.old.js

@@ -32,6 +32,7 @@ import {
   disableSchedulerTimeoutInWorkLoop,
   enableStrictEffects,
   skipUnmountedBoundaries,
+  enableSyncDefaultUpdates,
 } from 'shared/ReactFeatureFlags';
 import ReactSharedInternals from 'shared/ReactSharedInternals';
 import invariant from 'shared/invariant';
@@ -137,6 +138,8 @@ import {
   NoLanes,
   NoLane,
   SyncLane,
+  DefaultLane,
+  DefaultHydrationLane,
   NoTimestamp,
   claimNextTransitionLane,
   claimNextRetryLane,
@@ -159,6 +162,8 @@ import {
   markRootFinished,
   areLanesExpired,
   getHighestPriorityLane,
+  InputContinuousLane,
+  InputContinuousHydrationLane,
 } from './ReactFiberLane.old';
 import {
   DiscreteEventPriority,
@@ -426,6 +431,13 @@ export function requestUpdateLane(fiber: Fiber): Lane {
   // TODO: Move this type conversion to the event priority module.
   const updateLane: Lane = (getCurrentUpdatePriority(): any);
   if (updateLane !== NoLane) {
+    if (
+      enableSyncDefaultUpdates &&
+      (updateLane === InputContinuousLane ||
+        updateLane === InputContinuousHydrationLane)
+    ) {
+      return DefaultLane;
+    }
     return updateLane;
   }
 
@@ -682,7 +694,16 @@ function ensureRootIsScheduled(root: FiberRoot, currentTime: number) {
 
   // Schedule a new callback.
   let newCallbackNode;
-  if (newCallbackPriority === SyncLane) {
+  if (
+    enableSyncDefaultUpdates &&
+    (newCallbackPriority === DefaultLane ||
+      newCallbackPriority === DefaultHydrationLane)
+  ) {
+    newCallbackNode = scheduleCallback(
+      ImmediateSchedulerPriority,
+      performSyncWorkOnRoot.bind(null, root),
+    );
+  } else if (newCallbackPriority === SyncLane) {
     // Special case: Sync React callbacks are scheduled on a special
     // internal queue
     scheduleSyncCallback(performSyncWorkOnRoot.bind(null, root));
@@ -1017,7 +1038,11 @@ function performSyncWorkOnRoot(root) {
   const finishedWork: Fiber = (root.current.alternate: any);
   root.finishedWork = finishedWork;
   root.finishedLanes = lanes;
-  commitRoot(root);
+  if (enableSyncDefaultUpdates && includesSomeLane(lanes, DefaultLane)) {
+    finishConcurrentRender(root, exitStatus, lanes);
+  } else {
+    commitRoot(root);
+  }
 
   // Before exiting, make sure there's a callback scheduled for the next
   // pending level.