Add feature flag for setting update lane priority (#19401)

* Add feature flag for setting update lane priority * Remove second feature flag * Refactor feature flag locations * Add missing else
facebook · Aug 6, 2020 · 32ff428 · 32ff428
1 parent 5bdd4c8
commit 32ff428
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Showing 7 changed files with 479 additions and 223 deletions.
diff --git a/packages/react-dom/src/events/ReactDOMEventListener.js b/packages/react-dom/src/events/ReactDOMEventListener.js
@@ -38,7 +38,10 @@ import {
 import getEventTarget from './getEventTarget';
 import {getClosestInstanceFromNode} from '../client/ReactDOMComponentTree';
 
-import {enableLegacyFBSupport} from 'shared/ReactFeatureFlags';
+import {
+  enableLegacyFBSupport,
+  decoupleUpdatePriorityFromScheduler,
+} from 'shared/ReactFeatureFlags';
 import {
   UserBlockingEvent,
   ContinuousEvent,
@@ -147,10 +150,25 @@ function dispatchUserBlockingUpdate(
   container,
   nativeEvent,
 ) {
-  // TODO: Double wrapping is necessary while we decouple Scheduler priority.
-  const previousPriority = getCurrentUpdateLanePriority();
-  try {
-    setCurrentUpdateLanePriority(InputContinuousLanePriority);
+  if (decoupleUpdatePriorityFromScheduler) {
+    const previousPriority = getCurrentUpdateLanePriority();
+    try {
+      // TODO: Double wrapping is necessary while we decouple Scheduler priority.
+      setCurrentUpdateLanePriority(InputContinuousLanePriority);
+      runWithPriority(
+        UserBlockingPriority,
+        dispatchEvent.bind(
+          null,
+          domEventName,
+          eventSystemFlags,
+          container,
+          nativeEvent,
+        ),
+      );
+    } finally {
+      setCurrentUpdateLanePriority(previousPriority);
+    }
+  } else {
     runWithPriority(
       UserBlockingPriority,
       dispatchEvent.bind(
@@ -161,8 +179,6 @@ function dispatchUserBlockingUpdate(
         nativeEvent,
       ),
     );
-  } finally {
-    setCurrentUpdateLanePriority(previousPriority);
   }
 }
 

diff --git a/packages/react-reconciler/src/ReactFiberHooks.new.js b/packages/react-reconciler/src/ReactFiberHooks.new.js
@@ -26,6 +26,7 @@ import {
   enableDebugTracing,
   enableSchedulingProfiler,
   enableNewReconciler,
+  decoupleUpdatePriorityFromScheduler,
 } from 'shared/ReactFeatureFlags';
 
 import {NoMode, BlockingMode, DebugTracingMode} from './ReactTypeOfMode';
@@ -1506,34 +1507,64 @@ function rerenderDeferredValue<T>(
 
 function startTransition(setPending, config, callback) {
   const priorityLevel = getCurrentPriorityLevel();
-  const previousLanePriority = getCurrentUpdateLanePriority();
-  setCurrentUpdateLanePriority(
-    higherLanePriority(previousLanePriority, InputContinuousLanePriority),
-  );
-  runWithPriority(
-    priorityLevel < UserBlockingPriority ? UserBlockingPriority : priorityLevel,
-    () => {
-      setPending(true);
-    },
-  );
+  if (decoupleUpdatePriorityFromScheduler) {
+    const previousLanePriority = getCurrentUpdateLanePriority();
+    setCurrentUpdateLanePriority(
+      higherLanePriority(previousLanePriority, InputContinuousLanePriority),
+    );
 
-  // If there's no SuspenseConfig set, we'll use the DefaultLanePriority for this transition.
-  setCurrentUpdateLanePriority(DefaultLanePriority);
+    runWithPriority(
+      priorityLevel < UserBlockingPriority
+        ? UserBlockingPriority
+        : priorityLevel,
+      () => {
+        setPending(true);
+      },
+    );
 
-  runWithPriority(
-    priorityLevel > NormalPriority ? NormalPriority : priorityLevel,
-    () => {
-      const previousConfig = ReactCurrentBatchConfig.suspense;
-      ReactCurrentBatchConfig.suspense = config === undefined ? null : config;
-      try {
-        setPending(false);
-        callback();
-      } finally {
-        setCurrentUpdateLanePriority(previousLanePriority);
-        ReactCurrentBatchConfig.suspense = previousConfig;
-      }
-    },
-  );
+    // If there's no SuspenseConfig set, we'll use the DefaultLanePriority for this transition.
+    setCurrentUpdateLanePriority(DefaultLanePriority);
+
+    runWithPriority(
+      priorityLevel > NormalPriority ? NormalPriority : priorityLevel,
+      () => {
+        const previousConfig = ReactCurrentBatchConfig.suspense;
+        ReactCurrentBatchConfig.suspense = config === undefined ? null : config;
+        try {
+          setPending(false);
+          callback();
+        } finally {
+          if (decoupleUpdatePriorityFromScheduler) {
+            setCurrentUpdateLanePriority(previousLanePriority);
+          }
+          ReactCurrentBatchConfig.suspense = previousConfig;
+        }
+      },
+    );
+  } else {
+    runWithPriority(
+      priorityLevel < UserBlockingPriority
+        ? UserBlockingPriority
+        : priorityLevel,
+      () => {
+        setPending(true);
+      },
+    );
+
+    runWithPriority(
+      priorityLevel > NormalPriority ? NormalPriority : priorityLevel,
+      () => {
+        const previousConfig = ReactCurrentBatchConfig.suspense;
+        ReactCurrentBatchConfig.suspense = config === undefined ? null : config;
+        try {
+          setPending(false);
+          callback();
+        } finally {
+          ReactCurrentBatchConfig.suspense = previousConfig;
+        }
+      },
+    );
+  }
 }
 
 function mountTransition(

diff --git a/packages/react-reconciler/src/ReactFiberHooks.old.js b/packages/react-reconciler/src/ReactFiberHooks.old.js
@@ -26,6 +26,7 @@ import {
   enableDebugTracing,
   enableSchedulingProfiler,
   enableNewReconciler,
+  decoupleUpdatePriorityFromScheduler,
 } from 'shared/ReactFeatureFlags';
 
 import {NoMode, BlockingMode, DebugTracingMode} from './ReactTypeOfMode';
@@ -1505,34 +1506,64 @@ function rerenderDeferredValue<T>(
 
 function startTransition(setPending, config, callback) {
   const priorityLevel = getCurrentPriorityLevel();
-  const previousLanePriority = getCurrentUpdateLanePriority();
-  setCurrentUpdateLanePriority(
-    higherLanePriority(previousLanePriority, InputContinuousLanePriority),
-  );
-  runWithPriority(
-    priorityLevel < UserBlockingPriority ? UserBlockingPriority : priorityLevel,
-    () => {
-      setPending(true);
-    },
-  );
+  if (decoupleUpdatePriorityFromScheduler) {
+    const previousLanePriority = getCurrentUpdateLanePriority();
+    setCurrentUpdateLanePriority(
+      higherLanePriority(previousLanePriority, InputContinuousLanePriority),
+    );
 
-  // If there's no SuspenseConfig set, we'll use the DefaultLanePriority for this transition.
-  setCurrentUpdateLanePriority(DefaultLanePriority);
+    runWithPriority(
+      priorityLevel < UserBlockingPriority
+        ? UserBlockingPriority
+        : priorityLevel,
+      () => {
+        setPending(true);
+      },
+    );
 
-  runWithPriority(
-    priorityLevel > NormalPriority ? NormalPriority : priorityLevel,
-    () => {
-      const previousConfig = ReactCurrentBatchConfig.suspense;
-      ReactCurrentBatchConfig.suspense = config === undefined ? null : config;
-      try {
-        setPending(false);
-        callback();
-      } finally {
-        setCurrentUpdateLanePriority(previousLanePriority);
-        ReactCurrentBatchConfig.suspense = previousConfig;
-      }
-    },
-  );
+    // If there's no SuspenseConfig set, we'll use the DefaultLanePriority for this transition.
+    setCurrentUpdateLanePriority(DefaultLanePriority);
+
+    runWithPriority(
+      priorityLevel > NormalPriority ? NormalPriority : priorityLevel,
+      () => {
+        const previousConfig = ReactCurrentBatchConfig.suspense;
+        ReactCurrentBatchConfig.suspense = config === undefined ? null : config;
+        try {
+          setPending(false);
+          callback();
+        } finally {
+          if (decoupleUpdatePriorityFromScheduler) {
+            setCurrentUpdateLanePriority(previousLanePriority);
+          }
+          ReactCurrentBatchConfig.suspense = previousConfig;
+        }
+      },
+    );
+  } else {
+    runWithPriority(
+      priorityLevel < UserBlockingPriority
+        ? UserBlockingPriority
+        : priorityLevel,
+      () => {
+        setPending(true);
+      },
+    );
+
+    runWithPriority(
+      priorityLevel > NormalPriority ? NormalPriority : priorityLevel,
+      () => {
+        const previousConfig = ReactCurrentBatchConfig.suspense;
+        ReactCurrentBatchConfig.suspense = config === undefined ? null : config;
+        try {
+          setPending(false);
+          callback();
+        } finally {
+          ReactCurrentBatchConfig.suspense = previousConfig;
+        }
+      },
+    );
+  }
 }
 
 function mountTransition(