Remove scheduler sampling profiler shared array buffer

No one has been using this data so there's no reason to collect it. Event log has been maintained and tests have been updated.

Author: Brian Vaughn

packages/scheduler/src/SchedulerFeatureFlags.js

@@ -8,7 +8,7 @@
 
 export const enableSchedulerDebugging = false;
 export const enableIsInputPending = false;
-export const enableProfiling = false;
+export const enableProfiling = __VARIANT__;
 
 // TODO: enable to fix https://github.com/facebook/react/issues/20756.
 export const enableSetImmediate = __VARIANT__;

packages/scheduler/src/SchedulerProfiling.js

@@ -10,45 +10,9 @@
 import type {PriorityLevel} from './SchedulerPriorities';
 import {enableProfiling} from './SchedulerFeatureFlags';
 
-import {NoPriority} from './SchedulerPriorities';
-
 let runIdCounter: number = 0;
 let mainThreadIdCounter: number = 0;
 
-const isEnabledSharedArrayBuffer =
-  // $FlowFixMe Flow doesn't know about SharedArrayBuffer
-  typeof SharedArrayBuffer === 'function' &&
-  // We only use SharedArrayBuffer when cross origin isolation is enabled.
-  typeof window !== 'undefined' &&
-  window.crossOriginIsolated === true;
-
-const profilingStateSize = 4;
-export const sharedProfilingBuffer = enableProfiling
-  ? isEnabledSharedArrayBuffer
-    ? new SharedArrayBuffer(profilingStateSize * Int32Array.BYTES_PER_ELEMENT)
-    : typeof ArrayBuffer === 'function'
-    ? new ArrayBuffer(profilingStateSize * Int32Array.BYTES_PER_ELEMENT)
-    : null // Don't crash the init path on IE9
-  : null;
-
-const profilingState =
-  enableProfiling && sharedProfilingBuffer !== null
-    ? new Int32Array(sharedProfilingBuffer)
-    : []; // We can't read this but it helps save bytes for null checks
-
-const PRIORITY = 0;
-const CURRENT_TASK_ID = 1;
-const CURRENT_RUN_ID = 2;
-const QUEUE_SIZE = 3;
-
-if (enableProfiling) {
-  profilingState[PRIORITY] = NoPriority;
-  // This is maintained with a counter, because the size of the priority queue
-  // array might include canceled tasks.
-  profilingState[QUEUE_SIZE] = 0;
-  profilingState[CURRENT_TASK_ID] = 0;
-}
-
 // Bytes per element is 4
 const INITIAL_EVENT_LOG_SIZE = 131072;
 const MAX_EVENT_LOG_SIZE = 524288; // Equivalent to 2 megabytes
@@ -116,8 +80,6 @@ export function markTaskStart(
   ms: number,
 ) {
   if (enableProfiling) {
-    profilingState[QUEUE_SIZE]++;
-
     if (eventLog !== null) {
       // performance.now returns a float, representing milliseconds. When the
       // event is logged, it's coerced to an int. Convert to microseconds to
@@ -136,10 +98,6 @@ export function markTaskCompleted(
   ms: number,
 ) {
   if (enableProfiling) {
-    profilingState[PRIORITY] = NoPriority;
-    profilingState[CURRENT_TASK_ID] = 0;
-    profilingState[QUEUE_SIZE]--;
-
     if (eventLog !== null) {
       logEvent([TaskCompleteEvent, ms * 1000, task.id]);
     }
@@ -155,8 +113,6 @@ export function markTaskCanceled(
   ms: number,
 ) {
   if (enableProfiling) {
-    profilingState[QUEUE_SIZE]--;
-
     if (eventLog !== null) {
       logEvent([TaskCancelEvent, ms * 1000, task.id]);
     }
@@ -172,10 +128,6 @@ export function markTaskErrored(
   ms: number,
 ) {
   if (enableProfiling) {
-    profilingState[PRIORITY] = NoPriority;
-    profilingState[CURRENT_TASK_ID] = 0;
-    profilingState[QUEUE_SIZE]--;
-
     if (eventLog !== null) {
       logEvent([TaskErrorEvent, ms * 1000, task.id]);
     }
@@ -193,10 +145,6 @@ export function markTaskRun(
   if (enableProfiling) {
     runIdCounter++;
 
-    profilingState[PRIORITY] = task.priorityLevel;
-    profilingState[CURRENT_TASK_ID] = task.id;
-    profilingState[CURRENT_RUN_ID] = runIdCounter;
-
     if (eventLog !== null) {
       logEvent([TaskRunEvent, ms * 1000, task.id, runIdCounter]);
     }
@@ -205,10 +153,6 @@ export function markTaskRun(
 
 export function markTaskYield(task: {id: number, ...}, ms: number) {
   if (enableProfiling) {
-    profilingState[PRIORITY] = NoPriority;
-    profilingState[CURRENT_TASK_ID] = 0;
-    profilingState[CURRENT_RUN_ID] = 0;
-
     if (eventLog !== null) {
       logEvent([TaskYieldEvent, ms * 1000, task.id, runIdCounter]);
     }

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

@@ -13,7 +13,6 @@
 'use strict';
 
 let Scheduler;
-let sharedProfilingArray;
 // let runWithPriority;
 let ImmediatePriority;
 let UserBlockingPriority;
@@ -59,10 +58,6 @@ describe('Scheduler', () => {
     jest.mock('scheduler', () => require('scheduler/unstable_mock'));
     Scheduler = require('scheduler');
 
-    sharedProfilingArray = new Int32Array(
-      Scheduler.unstable_Profiling.sharedProfilingBuffer,
-    );
-
     // runWithPriority = Scheduler.unstable_runWithPriority;
     ImmediatePriority = Scheduler.unstable_ImmediatePriority;
     UserBlockingPriority = Scheduler.unstable_UserBlockingPriority;
@@ -76,20 +71,6 @@ describe('Scheduler', () => {
     // shouldYield = Scheduler.unstable_shouldYield;
   });
 
-  const PRIORITY = 0;
-  const CURRENT_TASK_ID = 1;
-  const CURRENT_RUN_ID = 2;
-  const QUEUE_SIZE = 3;
-
-  afterEach(() => {
-    if (sharedProfilingArray[QUEUE_SIZE] !== 0) {
-      throw Error(
-        'Test exited, but the shared profiling buffer indicates that a task ' +
-          'is still running',
-      );
-    }
-  });
-
   const TaskStartEvent = 1;
   const TaskCompleteEvent = 2;
   const TaskErrorEvent = 3;
@@ -272,23 +253,6 @@ describe('Scheduler', () => {
     return '\n' + result;
   }
 
-  function getProfilingInfo() {
-    const queueSize = sharedProfilingArray[QUEUE_SIZE];
-    if (queueSize === 0) {
-      return 'Empty Queue';
-    }
-    const priorityLevel = sharedProfilingArray[PRIORITY];
-    if (priorityLevel === 0) {
-      return 'Suspended, Queue Size: ' + queueSize;
-    }
-    return (
-      `Task: ${sharedProfilingArray[CURRENT_TASK_ID]}, ` +
-      `Run: ${sharedProfilingArray[CURRENT_RUN_ID]}, ` +
-      `Priority: ${priorityLevelToString(priorityLevel)}, ` +
-      `Queue Size: ${sharedProfilingArray[QUEUE_SIZE]}`
-    );
-  }
-
   it('creates a basic flamegraph', () => {
     Scheduler.unstable_Profiling.startLoggingProfilingEvents();
 
@@ -297,35 +261,27 @@ describe('Scheduler', () => {
       NormalPriority,
       () => {
         Scheduler.unstable_advanceTime(300);
-        Scheduler.unstable_yieldValue(getProfilingInfo());
+        Scheduler.unstable_yieldValue('Yield 1');
         scheduleCallback(
           UserBlockingPriority,
           () => {
-            Scheduler.unstable_yieldValue(getProfilingInfo());
+            Scheduler.unstable_yieldValue('Yield 2');
             Scheduler.unstable_advanceTime(300);
           },
           {label: 'Bar'},
         );
         Scheduler.unstable_advanceTime(100);
-        Scheduler.unstable_yieldValue('Yield');
+        Scheduler.unstable_yieldValue('Yield 3');
         return () => {
-          Scheduler.unstable_yieldValue(getProfilingInfo());
+          Scheduler.unstable_yieldValue('Yield 4');
           Scheduler.unstable_advanceTime(300);
         };
       },
       {label: 'Foo'},
     );
-    expect(Scheduler).toFlushAndYieldThrough([
-      'Task: 1, Run: 1, Priority: Normal, Queue Size: 1',
-      'Yield',
-    ]);
+    expect(Scheduler).toFlushAndYieldThrough(['Yield 1', 'Yield 3']);
     Scheduler.unstable_advanceTime(100);
-    expect(Scheduler).toFlushAndYield([
-      'Task: 2, Run: 2, Priority: User-blocking, Queue Size: 2',
-      'Task: 1, Run: 3, Priority: Normal, Queue Size: 1',
-    ]);
-
-    expect(getProfilingInfo()).toEqual('Empty Queue');
+    expect(Scheduler).toFlushAndYield(['Yield 2', 'Yield 4']);
 
     expect(stopProfilingAndPrintFlamegraph()).toEqual(
       `
@@ -340,19 +296,16 @@ Task 1 [Normal]              │  ████████░░░░░░░
     Scheduler.unstable_Profiling.startLoggingProfilingEvents();
 
     const task = scheduleCallback(NormalPriority, () => {
-      Scheduler.unstable_yieldValue(getProfilingInfo());
+      Scheduler.unstable_yieldValue('Yield 1');
       Scheduler.unstable_advanceTime(300);
-      Scheduler.unstable_yieldValue('Yield');
+      Scheduler.unstable_yieldValue('Yield 2');
       return () => {
         Scheduler.unstable_yieldValue('Continuation');
         Scheduler.unstable_advanceTime(200);
       };
     });
 
-    expect(Scheduler).toFlushAndYieldThrough([
-      'Task: 1, Run: 1, Priority: Normal, Queue Size: 1',
-      'Yield',
-    ]);
+    expect(Scheduler).toFlushAndYieldThrough(['Yield 1', 'Yield 2']);
     Scheduler.unstable_advanceTime(100);
 
     cancelCallback(task);
@@ -392,28 +345,25 @@ Task 1 [Normal]              │██████🡐 errored
     Scheduler.unstable_Profiling.startLoggingProfilingEvents();
 
     const task1 = scheduleCallback(NormalPriority, () => {
-      Scheduler.unstable_yieldValue(getProfilingInfo());
+      Scheduler.unstable_yieldValue('Yield 1');
       Scheduler.unstable_advanceTime(300);
-      Scheduler.unstable_yieldValue('Yield');
+      Scheduler.unstable_yieldValue('Yield 2');
       return () => {
         Scheduler.unstable_yieldValue('Continuation');
         Scheduler.unstable_advanceTime(200);
       };
     });
     const task2 = scheduleCallback(NormalPriority, () => {
-      Scheduler.unstable_yieldValue(getProfilingInfo());
+      Scheduler.unstable_yieldValue('Yield 3');
       Scheduler.unstable_advanceTime(300);
-      Scheduler.unstable_yieldValue('Yield');
+      Scheduler.unstable_yieldValue('Yield 4');
       return () => {
         Scheduler.unstable_yieldValue('Continuation');
         Scheduler.unstable_advanceTime(200);
       };
     });
 
-    expect(Scheduler).toFlushAndYieldThrough([
-      'Task: 1, Run: 1, Priority: Normal, Queue Size: 2',
-      'Yield',
-    ]);
+    expect(Scheduler).toFlushAndYieldThrough(['Yield 1', 'Yield 2']);
     Scheduler.unstable_advanceTime(100);
 
     cancelCallback(task1);

packages/scheduler/src/forks/SchedulerDOM.js

@@ -25,7 +25,6 @@ import {
   IdlePriority,
 } from '../SchedulerPriorities';
 import {
-  sharedProfilingBuffer,
   markTaskRun,
   markTaskYield,
   markTaskCompleted,
@@ -624,6 +623,5 @@ export const unstable_Profiling = enableProfiling
   ? {
       startLoggingProfilingEvents,
       stopLoggingProfilingEvents,
-      sharedProfilingBuffer,
     }
   : null;

packages/scheduler/src/forks/SchedulerMock.js

@@ -23,7 +23,6 @@ import {
   IdlePriority,
 } from '../SchedulerPriorities';
 import {
-  sharedProfilingBuffer,
   markTaskRun,
   markTaskYield,
   markTaskCompleted,
@@ -635,6 +634,5 @@ export const unstable_Profiling = enableProfiling
   ? {
       startLoggingProfilingEvents,
       stopLoggingProfilingEvents,
-      sharedProfilingBuffer,
     }
   : null;

packages/scheduler/src/forks/SchedulerNoDOM.js

@@ -23,7 +23,6 @@ import {
   IdlePriority,
 } from '../SchedulerPriorities';
 import {
-  sharedProfilingBuffer,
   markTaskRun,
   markTaskYield,
   markTaskCompleted,
@@ -470,6 +469,5 @@ export const unstable_Profiling = enableProfiling
   ? {
       startLoggingProfilingEvents,
       stopLoggingProfilingEvents,
-      sharedProfilingBuffer,
     }
   : null;

packages/scheduler/src/forks/SchedulerPostTaskOnly.js

@@ -24,7 +24,6 @@ import {
   IdlePriority,
 } from '../SchedulerPriorities';
 import {
-  sharedProfilingBuffer,
   markTaskRun,
   markTaskYield,
   markTaskCompleted,
@@ -595,6 +594,5 @@ export const unstable_Profiling = enableProfiling
   ? {
       startLoggingProfilingEvents,
       stopLoggingProfilingEvents,
-      sharedProfilingBuffer,
     }
   : null;