clean up isInputPending

Author: noahlemen

packages/scheduler/src/SchedulerFeatureFlags.js

@@ -8,12 +8,8 @@
  */
 
 export const enableSchedulerDebugging = false;
-export const enableIsInputPending = false;
 export const enableProfiling = false;
-export const enableIsInputPendingContinuous = false;
 export const frameYieldMs = 5;
-export const continuousYieldMs = 50;
-export const maxYieldMs = 300;
 
 export const userBlockingPriorityTimeout = 250;
 export const normalPriorityTimeout = 5000;

packages/scheduler/src/__tests__/Scheduler-test.js

@@ -339,15 +339,7 @@ describe('SchedulerBrowser', () => {
     runtime.assertLog([
       'Message Event',
       'Task with no pending input',
-      // Even though there's no input, eventually Scheduler will yield
-      // regardless in case there's a pending main thread task we don't know
-      // about, like a network event.
-      gate(flags =>
-        flags.enableIsInputPending
-          ? 'Yield at 10ms'
-          : // When isInputPending is disabled, we always yield quickly
-            'Yield at 5ms',
-      ),
+      'Yield at 5ms',
     ]);
 
     runtime.resetTime();
@@ -393,15 +385,7 @@ describe('SchedulerBrowser', () => {
       runtime.assertLog([
         'Message Event',
         'Task with no pending input',
-        // Even though there's no input, eventually Scheduler will yield
-        // regardless in case there's a pending main thread task we don't know
-        // about, like a network event.
-        gate(flags =>
-          flags.enableIsInputPending
-            ? 'Yield at 10ms'
-            : // When isInputPending is disabled, we always yield quickly
-              'Yield at 5ms',
-        ),
+        'Yield at 5ms',
       ]);
 
       runtime.resetTime();
@@ -419,14 +403,7 @@ describe('SchedulerBrowser', () => {
       runtime.assertLog([
         'Message Event',
         'Task with continuous input',
-        // This time we yielded quickly to unblock the continuous event. But not
-        // as quickly as for a discrete event.
-        gate(flags =>
-          flags.enableIsInputPending
-            ? 'Yield at 10ms'
-            : // When isInputPending is disabled, we always yield quickly
-              'Yield at 5ms',
-        ),
+        'Yield at 5ms',
         'Continuous Event',
       ]);
     },
@@ -448,16 +425,7 @@ describe('SchedulerBrowser', () => {
     runtime.assertLog(['Post Message']);
 
     runtime.fireMessageEvent();
-    runtime.assertLog([
-      'Message Event',
-      'Task with no paint',
-      gate(flags =>
-        flags.enableIsInputPending
-          ? 'Yield at 10ms'
-          : // When isInputPending is disabled, we always yield quickly
-            'Yield at 5ms',
-      ),
-    ]);
+    runtime.assertLog(['Message Event', 'Task with no paint', 'Yield at 5ms']);
 
     runtime.resetTime();
 

packages/scheduler/src/forks/Scheduler.js

@@ -14,11 +14,7 @@ import type {PriorityLevel} from '../SchedulerPriorities';
 import {
   enableSchedulerDebugging,
   enableProfiling,
-  enableIsInputPending,
-  enableIsInputPendingContinuous,
   frameYieldMs,
-  continuousYieldMs,
-  maxYieldMs,
   userBlockingPriorityTimeout,
   lowPriorityTimeout,
   normalPriorityTimeout,
@@ -104,17 +100,6 @@ const localClearTimeout =
 const localSetImmediate =
   typeof setImmediate !== 'undefined' ? setImmediate : null; // IE and Node.js + jsdom
 
-const isInputPending =
-  typeof navigator !== 'undefined' &&
-  // $FlowFixMe[prop-missing]
-  navigator.scheduling !== undefined &&
-  // $FlowFixMe[incompatible-type]
-  navigator.scheduling.isInputPending !== undefined
-    ? navigator.scheduling.isInputPending.bind(navigator.scheduling)
-    : null;
-
-const continuousOptions = {includeContinuous: enableIsInputPendingContinuous};
-
 function advanceTimers(currentTime: number) {
   // Check for tasks that are no longer delayed and add them to the queue.
   let timer = peek(timerQueue);
@@ -468,71 +453,20 @@ let taskTimeoutID: TimeoutID = (-1: any);
 // It does not attempt to align with frame boundaries, since most tasks don't
 // need to be frame aligned; for those that do, use requestAnimationFrame.
 let frameInterval = frameYieldMs;
-const continuousInputInterval = continuousYieldMs;
-const maxInterval = maxYieldMs;
 let startTime = -1;
 
-let needsPaint = false;
-
 function shouldYieldToHost(): boolean {
   const timeElapsed = getCurrentTime() - startTime;
   if (timeElapsed < frameInterval) {
     // The main thread has only been blocked for a really short amount of time;
     // smaller than a single frame. Don't yield yet.
     return false;
   }
-
-  // The main thread has been blocked for a non-negligible amount of time. We
-  // may want to yield control of the main thread, so the browser can perform
-  // high priority tasks. The main ones are painting and user input. If there's
-  // a pending paint or a pending input, then we should yield. But if there's
-  // neither, then we can yield less often while remaining responsive. We'll
-  // eventually yield regardless, since there could be a pending paint that
-  // wasn't accompanied by a call to `requestPaint`, or other main thread tasks
-  // like network events.
-  if (enableIsInputPending) {
-    if (needsPaint) {
-      // There's a pending paint (signaled by `requestPaint`). Yield now.
-      return true;
-    }
-    if (timeElapsed < continuousInputInterval) {
-      // We haven't blocked the thread for that long. Only yield if there's a
-      // pending discrete input (e.g. click). It's OK if there's pending
-      // continuous input (e.g. mouseover).
-      if (isInputPending !== null) {
-        return isInputPending();
-      }
-    } else if (timeElapsed < maxInterval) {
-      // Yield if there's either a pending discrete or continuous input.
-      if (isInputPending !== null) {
-        return isInputPending(continuousOptions);
-      }
-    } else {
-      // We've blocked the thread for a long time. Even if there's no pending
-      // input, there may be some other scheduled work that we don't know about,
-      // like a network event. Yield now.
-      return true;
-    }
-  }
-
-  // `isInputPending` isn't available. Yield now.
+  // Yield now.
   return true;
 }
 
-function requestPaint() {
-  if (
-    enableIsInputPending &&
-    navigator !== undefined &&
-    // $FlowFixMe[prop-missing]
-    navigator.scheduling !== undefined &&
-    // $FlowFixMe[incompatible-type]
-    navigator.scheduling.isInputPending !== undefined
-  ) {
-    needsPaint = true;
-  }
-
-  // Since we yield every frame regardless, `requestPaint` has no effect.
-}
+function requestPaint() {}
 
 function forceFrameRate(fps: number) {
   if (fps < 0 || fps > 125) {
@@ -577,9 +511,6 @@ const performWorkUntilDeadline = () => {
       }
     }
   }
-  // Yielding to the browser will give it a chance to paint, so we can
-  // reset this.
-  needsPaint = false;
 };
 
 let schedulePerformWorkUntilDeadline;

packages/scheduler/src/forks/SchedulerFeatureFlags.www-dynamic.js

@@ -13,11 +13,7 @@
 
 export const enableProfiling = __VARIANT__;
 
-export const enableIsInputPending = __VARIANT__;
-export const enableIsInputPendingContinuous = __VARIANT__;
 export const frameYieldMs = 5;
-export const continuousYieldMs = 10;
-export const maxYieldMs = 10;
 
 export const userBlockingPriorityTimeout = 250;
 export const normalPriorityTimeout = 5000;

packages/scheduler/src/forks/SchedulerFeatureFlags.www.js

@@ -16,11 +16,7 @@ export const {
   userBlockingPriorityTimeout,
   normalPriorityTimeout,
   lowPriorityTimeout,
-  enableIsInputPending,
-  enableIsInputPendingContinuous,
   frameYieldMs,
-  continuousYieldMs,
-  maxYieldMs,
 } = dynamicFeatureFlags;
 export const enableSchedulerDebugging = true;
 export const enableProfiling: boolean =