Avoid scheduling unnecessary callbacks for cleanup effects

Updated enqueuePendingPassiveEffectDestroyFn() to check rootDoesHavePassiveEffects before scheduling a new callback. This way we'll only schedule (at most) one.
facebook · Jan 30, 2020 · 167fcd3 · 167fcd3
1 parent e1ff76a
commit 167fcd3
Showing 1 changed file with 7 additions and 5 deletions.
diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.js b/packages/react-reconciler/src/ReactFiberWorkLoop.js
@@ -2183,11 +2183,13 @@ export function enqueuePendingPassiveEffectDestroyFn(
 ): void {
   if (deferPassiveEffectCleanupDuringUnmount) {
     pendingUnmountedPassiveEffectDestroyFunctions.push(destroy);
-    rootDoesHavePassiveEffects = true;
-    scheduleCallback(NormalPriority, () => {
-      flushPassiveEffects();
-      return null;
-    });
+    if (!rootDoesHavePassiveEffects) {
+      rootDoesHavePassiveEffects = true;
+      scheduleCallback(NormalPriority, () => {
+        flushPassiveEffects();
+        return null;
+      });
+    }
   }
 }