| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | * @flow |
| 8 | */ |
| 9 | |
| 10 | /* eslint-disable no-var */ |
| 11 | |
| 12 | import type {PriorityLevel} from '../SchedulerPriorities'; |
| 13 | |
| 14 | import { |
| 15 | enableProfiling, |
| 16 | frameYieldMs, |
| 17 | userBlockingPriorityTimeout, |
| 18 | lowPriorityTimeout, |
| 19 | normalPriorityTimeout, |
| 20 | enableRequestPaint, |
| 21 | enableAlwaysYieldScheduler, |
| 22 | } from '../SchedulerFeatureFlags'; |
| 23 | |
| 24 | import {push, pop, peek} from '../SchedulerMinHeap'; |
| 25 | |
| 26 | // TODO: Use symbols? |
| 27 | import { |
| 28 | ImmediatePriority, |
| 29 | UserBlockingPriority, |
| 30 | NormalPriority, |
| 31 | LowPriority, |
| 32 | IdlePriority, |
| 33 | } from '../SchedulerPriorities'; |
| 34 | import { |
| 35 | markTaskRun, |
| 36 | markTaskYield, |
| 37 | markTaskCompleted, |
| 38 | markTaskCanceled, |
| 39 | markTaskErrored, |
| 40 | markSchedulerSuspended, |
| 41 | markSchedulerUnsuspended, |
| 42 | markTaskStart, |
| 43 | stopLoggingProfilingEvents, |
| 44 | startLoggingProfilingEvents, |
| 45 | } from '../SchedulerProfiling'; |
| 46 | |
| 47 | export type Callback = boolean => ?Callback; |
| 48 | |
| 49 | export opaque type Task = { |
| 50 | id: number, |
| 51 | callback: Callback | null, |
| 52 | priorityLevel: PriorityLevel, |
| 53 | startTime: number, |
| 54 | expirationTime: number, |
| 55 | sortIndex: number, |
| 56 | isQueued?: boolean, |
| 57 | }; |
| 58 | |
| 59 | let getCurrentTime: () => number | DOMHighResTimeStamp; |
| 60 | const hasPerformanceNow = |
| 61 | // $FlowFixMe[method-unbinding] |
| 62 | typeof performance === 'object' && typeof performance.now === 'function'; |
| 63 | |
| 64 | if (hasPerformanceNow) { |
| 65 | const localPerformance = performance; |
| 66 | getCurrentTime = () => localPerformance.now(); |
| 67 | } else { |
| 68 | const localDate = Date; |
| 69 | const initialTime = localDate.now(); |
| 70 | getCurrentTime = () => localDate.now() - initialTime; |
| 71 | } |
| 72 | |
| 73 | // Max 31 bit integer. The max integer size in V8 for 32-bit systems. |
| 74 | // Math.pow(2, 30) - 1 |
| 75 | // 0b111111111111111111111111111111 |
| 76 | var maxSigned31BitInt = 1073741823; |
| 77 | |
| 78 | // Tasks are stored on a min heap |
| 79 | var taskQueue: Array<Task> = []; |
| 80 | var timerQueue: Array<Task> = []; |
| 81 | |
| 82 | // Incrementing id counter. Used to maintain insertion order. |
| 83 | var taskIdCounter = 1; |
| 84 | |
| 85 | var currentTask = null; |
| 86 | var currentPriorityLevel: PriorityLevel = NormalPriority; |
| 87 | |
| 88 | // This is set while performing work, to prevent re-entrance. |
| 89 | var isPerformingWork = false; |
| 90 | |
| 91 | var isHostCallbackScheduled = false; |
| 92 | var isHostTimeoutScheduled = false; |
| 93 | |
| 94 | var needsPaint = false; |
| 95 | |
| 96 | // Capture local references to native APIs, in case a polyfill overrides them. |
| 97 | const localSetTimeout = typeof setTimeout === 'function' ? setTimeout : null; |
| 98 | const localClearTimeout = |
| 99 | typeof clearTimeout === 'function' ? clearTimeout : null; |
| 100 | const localSetImmediate = |
| 101 | typeof setImmediate !== 'undefined' ? setImmediate : null; // IE and Node.js + jsdom |
| 102 | |
| 103 | function advanceTimers(currentTime: number) { |
| 104 | // Check for tasks that are no longer delayed and add them to the queue. |
| 105 | let timer = peek(timerQueue); |
| 106 | while (timer !== null) { |
| 107 | if (timer.callback === null) { |
| 108 | // Timer was cancelled. |
| 109 | pop(timerQueue); |
| 110 | } else if (timer.startTime <= currentTime) { |
| 111 | // Timer fired. Transfer to the task queue. |
| 112 | pop(timerQueue); |
| 113 | timer.sortIndex = timer.expirationTime; |
| 114 | push(taskQueue, timer); |
| 115 | // $FlowFixMe[constant-condition] |
| 116 | if (enableProfiling) { |
| 117 | markTaskStart(timer, currentTime); |
| 118 | timer.isQueued = true; |
| 119 | } |
| 120 | } else { |
| 121 | // Remaining timers are pending. |
| 122 | return; |
| 123 | } |
| 124 | timer = peek(timerQueue); |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | function handleTimeout(currentTime: number) { |
| 129 | isHostTimeoutScheduled = false; |
| 130 | advanceTimers(currentTime); |
| 131 | |
| 132 | if (!isHostCallbackScheduled) { |
| 133 | if (peek(taskQueue) !== null) { |
| 134 | isHostCallbackScheduled = true; |
| 135 | requestHostCallback(); |
| 136 | } else { |
| 137 | const firstTimer = peek(timerQueue); |
| 138 | if (firstTimer !== null) { |
| 139 | requestHostTimeout(handleTimeout, firstTimer.startTime - currentTime); |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | function flushWork(initialTime: number) { |
| 146 | // $FlowFixMe[constant-condition] |
| 147 | if (enableProfiling) { |
| 148 | markSchedulerUnsuspended(initialTime); |
| 149 | } |
| 150 | |
| 151 | // We'll need a host callback the next time work is scheduled. |
| 152 | isHostCallbackScheduled = false; |
| 153 | if (isHostTimeoutScheduled) { |
| 154 | // We scheduled a timeout but it's no longer needed. Cancel it. |
| 155 | isHostTimeoutScheduled = false; |
| 156 | cancelHostTimeout(); |
| 157 | } |
| 158 | |
| 159 | isPerformingWork = true; |
| 160 | const previousPriorityLevel = currentPriorityLevel; |
| 161 | try { |
| 162 | // $FlowFixMe[constant-condition] |
| 163 | if (enableProfiling) { |
| 164 | try { |
| 165 | return workLoop(initialTime); |
| 166 | } catch (error) { |
| 167 | if (currentTask !== null) { |
| 168 | const currentTime = getCurrentTime(); |
| 169 | // $FlowFixMe[incompatible-call] found when upgrading Flow |
| 170 | // $FlowFixMe[incompatible-type] |
| 171 | markTaskErrored(currentTask, currentTime); |
| 172 | // $FlowFixMe[incompatible-use] found when upgrading Flow |
| 173 | currentTask.isQueued = false; |
| 174 | } |
| 175 | throw error; |
| 176 | } |
| 177 | } else { |
| 178 | // No catch in prod code path. |
| 179 | return workLoop(initialTime); |
| 180 | } |
| 181 | } finally { |
| 182 | currentTask = null; |
| 183 | currentPriorityLevel = previousPriorityLevel; |
| 184 | isPerformingWork = false; |
| 185 | // $FlowFixMe[constant-condition] |
| 186 | if (enableProfiling) { |
| 187 | const currentTime = getCurrentTime(); |
| 188 | markSchedulerSuspended(currentTime); |
| 189 | } |
| 190 | } |
| 191 | } |
| 192 | |
| 193 | function workLoop(initialTime: number) { |
| 194 | let currentTime = initialTime; |
| 195 | advanceTimers(currentTime); |
| 196 | currentTask = peek(taskQueue); |
| 197 | while (currentTask !== null) { |
| 198 | if (!enableAlwaysYieldScheduler) { |
| 199 | if (currentTask.expirationTime > currentTime && shouldYieldToHost()) { |
| 200 | // This currentTask hasn't expired, and we've reached the deadline. |
| 201 | break; |
| 202 | } |
| 203 | } |
| 204 | // $FlowFixMe[incompatible-use] found when upgrading Flow |
| 205 | const callback = currentTask.callback; |
| 206 | if (typeof callback === 'function') { |
| 207 | // $FlowFixMe[incompatible-use] found when upgrading Flow |
| 208 | currentTask.callback = null; |
| 209 | // $FlowFixMe[incompatible-use] found when upgrading Flow |
| 210 | currentPriorityLevel = currentTask.priorityLevel; |
| 211 | // $FlowFixMe[incompatible-use] found when upgrading Flow |
| 212 | const didUserCallbackTimeout = currentTask.expirationTime <= currentTime; |
| 213 | // $FlowFixMe[constant-condition] |
| 214 | if (enableProfiling) { |
| 215 | // $FlowFixMe[incompatible-type] found when upgrading Flow |
| 216 | markTaskRun(currentTask, currentTime); |
| 217 | } |
| 218 | const continuationCallback = callback(didUserCallbackTimeout); |
| 219 | currentTime = getCurrentTime(); |
| 220 | if (typeof continuationCallback === 'function') { |
| 221 | // If a continuation is returned, immediately yield to the main thread |
| 222 | // regardless of how much time is left in the current time slice. |
| 223 | // $FlowFixMe[incompatible-use] found when upgrading Flow |
| 224 | currentTask.callback = continuationCallback; |
| 225 | // $FlowFixMe[constant-condition] |
| 226 | if (enableProfiling) { |
| 227 | // $FlowFixMe[incompatible-type] found when upgrading Flow |
| 228 | markTaskYield(currentTask, currentTime); |
| 229 | } |
| 230 | advanceTimers(currentTime); |
| 231 | return true; |
| 232 | } else { |
| 233 | // $FlowFixMe[constant-condition] |
| 234 | if (enableProfiling) { |
| 235 | // $FlowFixMe[incompatible-type] found when upgrading Flow |
| 236 | markTaskCompleted(currentTask, currentTime); |
| 237 | // $FlowFixMe[incompatible-use] found when upgrading Flow |
| 238 | currentTask.isQueued = false; |
| 239 | } |
| 240 | if (currentTask === peek(taskQueue)) { |
| 241 | pop(taskQueue); |
| 242 | } |
| 243 | advanceTimers(currentTime); |
| 244 | } |
| 245 | } else { |
| 246 | pop(taskQueue); |
| 247 | } |
| 248 | currentTask = peek(taskQueue); |
| 249 | if (enableAlwaysYieldScheduler) { |
| 250 | if (currentTask === null || currentTask.expirationTime > currentTime) { |
| 251 | // This currentTask hasn't expired we yield to the browser task. |
| 252 | break; |
| 253 | } |
| 254 | } |
| 255 | } |
| 256 | // Return whether there's additional work |
| 257 | if (currentTask !== null) { |
| 258 | return true; |
| 259 | } else { |
| 260 | const firstTimer = peek(timerQueue); |
| 261 | if (firstTimer !== null) { |
| 262 | requestHostTimeout(handleTimeout, firstTimer.startTime - currentTime); |
| 263 | } |
| 264 | return false; |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | function unstable_runWithPriority<T>( |
| 269 | priorityLevel: PriorityLevel, |
| 270 | eventHandler: () => T, |
| 271 | ): T { |
| 272 | switch (priorityLevel) { |
| 273 | case ImmediatePriority: |
| 274 | case UserBlockingPriority: |
| 275 | case NormalPriority: |
| 276 | case LowPriority: |
| 277 | case IdlePriority: |
| 278 | break; |
| 279 | default: |
| 280 | priorityLevel = NormalPriority; |
| 281 | } |
| 282 | |
| 283 | var previousPriorityLevel = currentPriorityLevel; |
| 284 | currentPriorityLevel = priorityLevel; |
| 285 | |
| 286 | try { |
| 287 | return eventHandler(); |
| 288 | } finally { |
| 289 | currentPriorityLevel = previousPriorityLevel; |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | function unstable_next<T>(eventHandler: () => T): T { |
| 294 | var priorityLevel: PriorityLevel; |
| 295 | switch (currentPriorityLevel) { |
| 296 | case ImmediatePriority: |
| 297 | case UserBlockingPriority: |
| 298 | case NormalPriority: |
| 299 | // Shift down to normal priority |
| 300 | priorityLevel = NormalPriority; |
| 301 | break; |
| 302 | default: |
| 303 | // Anything lower than normal priority should remain at the current level. |
| 304 | priorityLevel = currentPriorityLevel; |
| 305 | break; |
| 306 | } |
| 307 | |
| 308 | var previousPriorityLevel = currentPriorityLevel; |
| 309 | currentPriorityLevel = priorityLevel; |
| 310 | |
| 311 | try { |
| 312 | return eventHandler(); |
| 313 | } finally { |
| 314 | currentPriorityLevel = previousPriorityLevel; |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | function unstable_wrapCallback<T: (...Array<mixed>) => mixed>(callback: T): T { |
| 319 | var parentPriorityLevel = currentPriorityLevel; |
| 320 | // $FlowFixMe[incompatible-type] |
| 321 | // $FlowFixMe[missing-this-annot] |
| 322 | return function () { |
| 323 | // This is a fork of runWithPriority, inlined for performance. |
| 324 | var previousPriorityLevel = currentPriorityLevel; |
| 325 | currentPriorityLevel = parentPriorityLevel; |
| 326 | |
| 327 | try { |
| 328 | return callback.apply(this, arguments); |
| 329 | } finally { |
| 330 | currentPriorityLevel = previousPriorityLevel; |
| 331 | } |
| 332 | }; |
| 333 | } |
| 334 | |
| 335 | function unstable_scheduleCallback( |
| 336 | priorityLevel: PriorityLevel, |
| 337 | callback: Callback, |
| 338 | options?: {delay: number}, |
| 339 | ): Task { |
| 340 | var currentTime = getCurrentTime(); |
| 341 | |
| 342 | var startTime; |
| 343 | // $FlowFixMe[invalid-compare] |
| 344 | if (typeof options === 'object' && options !== null) { |
| 345 | var delay = options.delay; |
| 346 | if (typeof delay === 'number' && delay > 0) { |
| 347 | startTime = currentTime + delay; |
| 348 | } else { |
| 349 | startTime = currentTime; |
| 350 | } |
| 351 | } else { |
| 352 | startTime = currentTime; |
| 353 | } |
| 354 | |
| 355 | var timeout; |
| 356 | switch (priorityLevel) { |
| 357 | case ImmediatePriority: |
| 358 | // Times out immediately |
| 359 | timeout = -1; |
| 360 | break; |
| 361 | case UserBlockingPriority: |
| 362 | // Eventually times out |
| 363 | timeout = userBlockingPriorityTimeout; |
| 364 | break; |
| 365 | case IdlePriority: |
| 366 | // Never times out |
| 367 | timeout = maxSigned31BitInt; |
| 368 | break; |
| 369 | case LowPriority: |
| 370 | // Eventually times out |
| 371 | timeout = lowPriorityTimeout; |
| 372 | break; |
| 373 | case NormalPriority: |
| 374 | default: |
| 375 | // Eventually times out |
| 376 | timeout = normalPriorityTimeout; |
| 377 | break; |
| 378 | } |
| 379 | |
| 380 | var expirationTime = startTime + timeout; |
| 381 | |
| 382 | var newTask: Task = { |
| 383 | id: taskIdCounter++, |
| 384 | callback, |
| 385 | priorityLevel, |
| 386 | startTime, |
| 387 | expirationTime, |
| 388 | sortIndex: -1, |
| 389 | }; |
| 390 | // $FlowFixMe[constant-condition] |
| 391 | if (enableProfiling) { |
| 392 | newTask.isQueued = false; |
| 393 | } |
| 394 | |
| 395 | if (startTime > currentTime) { |
| 396 | // This is a delayed task. |
| 397 | newTask.sortIndex = startTime; |
| 398 | push(timerQueue, newTask); |
| 399 | if (peek(taskQueue) === null && newTask === peek(timerQueue)) { |
| 400 | // All tasks are delayed, and this is the task with the earliest delay. |
| 401 | if (isHostTimeoutScheduled) { |
| 402 | // Cancel an existing timeout. |
| 403 | cancelHostTimeout(); |
| 404 | } else { |
| 405 | isHostTimeoutScheduled = true; |
| 406 | } |
| 407 | // Schedule a timeout. |
| 408 | requestHostTimeout(handleTimeout, startTime - currentTime); |
| 409 | } |
| 410 | } else { |
| 411 | newTask.sortIndex = expirationTime; |
| 412 | push(taskQueue, newTask); |
| 413 | // $FlowFixMe[constant-condition] |
| 414 | if (enableProfiling) { |
| 415 | markTaskStart(newTask, currentTime); |
| 416 | newTask.isQueued = true; |
| 417 | } |
| 418 | // Schedule a host callback, if needed. If we're already performing work, |
| 419 | // wait until the next time we yield. |
| 420 | if (!isHostCallbackScheduled && !isPerformingWork) { |
| 421 | isHostCallbackScheduled = true; |
| 422 | requestHostCallback(); |
| 423 | } |
| 424 | } |
| 425 | |
| 426 | return newTask; |
| 427 | } |
| 428 | |
| 429 | function unstable_cancelCallback(task: Task) { |
| 430 | // $FlowFixMe[constant-condition] |
| 431 | if (enableProfiling) { |
| 432 | if (task.isQueued) { |
| 433 | const currentTime = getCurrentTime(); |
| 434 | markTaskCanceled(task, currentTime); |
| 435 | task.isQueued = false; |
| 436 | } |
| 437 | } |
| 438 | |
| 439 | // Null out the callback to indicate the task has been canceled. (Can't |
| 440 | // remove from the queue because you can't remove arbitrary nodes from an |
| 441 | // array based heap, only the first one.) |
| 442 | task.callback = null; |
| 443 | } |
| 444 | |
| 445 | function unstable_getCurrentPriorityLevel(): PriorityLevel { |
| 446 | return currentPriorityLevel; |
| 447 | } |
| 448 | |
| 449 | let isMessageLoopRunning = false; |
| 450 | let taskTimeoutID: TimeoutID = -1 as any; |
| 451 | |
| 452 | // Scheduler periodically yields in case there is other work on the main |
| 453 | // thread, like user events. By default, it yields multiple times per frame. |
| 454 | // It does not attempt to align with frame boundaries, since most tasks don't |
| 455 | // need to be frame aligned; for those that do, use requestAnimationFrame. |
| 456 | let frameInterval: number = frameYieldMs; |
| 457 | let startTime = -1; |
| 458 | |
| 459 | function shouldYieldToHost(): boolean { |
| 460 | if (!enableAlwaysYieldScheduler && enableRequestPaint && needsPaint) { |
| 461 | // Yield now. |
| 462 | return true; |
| 463 | } |
| 464 | const timeElapsed = getCurrentTime() - startTime; |
| 465 | if (timeElapsed < frameInterval) { |
| 466 | // The main thread has only been blocked for a really short amount of time; |
| 467 | // smaller than a single frame. Don't yield yet. |
| 468 | return false; |
| 469 | } |
| 470 | // Yield now. |
| 471 | return true; |
| 472 | } |
| 473 | |
| 474 | function requestPaint() { |
| 475 | // $FlowFixMe[constant-condition] |
| 476 | if (enableRequestPaint) { |
| 477 | needsPaint = true; |
| 478 | } |
| 479 | } |
| 480 | |
| 481 | function forceFrameRate(fps: number) { |
| 482 | if (fps < 0 || fps > 125) { |
| 483 | // Using console['error'] to evade Babel and ESLint |
| 484 | console['error']( |
| 485 | 'forceFrameRate takes a positive int between 0 and 125, ' + |
| 486 | 'forcing frame rates higher than 125 fps is not supported', |
| 487 | ); |
| 488 | return; |
| 489 | } |
| 490 | if (fps > 0) { |
| 491 | frameInterval = Math.floor(1000 / fps); |
| 492 | } else { |
| 493 | // reset the framerate |
| 494 | frameInterval = frameYieldMs; |
| 495 | } |
| 496 | } |
| 497 | |
| 498 | const performWorkUntilDeadline = () => { |
| 499 | // $FlowFixMe[constant-condition] |
| 500 | if (enableRequestPaint) { |
| 501 | needsPaint = false; |
| 502 | } |
| 503 | if (isMessageLoopRunning) { |
| 504 | const currentTime = getCurrentTime(); |
| 505 | // Keep track of the start time so we can measure how long the main thread |
| 506 | // has been blocked. |
| 507 | startTime = currentTime; |
| 508 | |
| 509 | // If a scheduler task throws, exit the current browser task so the |
| 510 | // error can be observed. |
| 511 | // |
| 512 | // Intentionally not using a try-catch, since that makes some debugging |
| 513 | // techniques harder. Instead, if `flushWork` errors, then `hasMoreWork` will |
| 514 | // remain true, and we'll continue the work loop. |
| 515 | let hasMoreWork = true; |
| 516 | try { |
| 517 | hasMoreWork = flushWork(currentTime); |
| 518 | } finally { |
| 519 | if (hasMoreWork) { |
| 520 | // If there's more work, schedule the next message event at the end |
| 521 | // of the preceding one. |
| 522 | schedulePerformWorkUntilDeadline(); |
| 523 | } else { |
| 524 | isMessageLoopRunning = false; |
| 525 | } |
| 526 | } |
| 527 | } |
| 528 | }; |
| 529 | |
| 530 | let schedulePerformWorkUntilDeadline; |
| 531 | if (typeof localSetImmediate === 'function') { |
| 532 | // Node.js and old IE. |
| 533 | // There's a few reasons for why we prefer setImmediate. |
| 534 | // |
| 535 | // Unlike MessageChannel, it doesn't prevent a Node.js process from exiting. |
| 536 | // (Even though this is a DOM fork of the Scheduler, you could get here |
| 537 | // with a mix of Node.js 15+, which has a MessageChannel, and jsdom.) |
| 538 | // https://github.com/facebook/react/issues/20756 |
| 539 | // |
| 540 | // But also, it runs earlier which is the semantic we want. |
| 541 | // If other browsers ever implement it, it's better to use it. |
| 542 | // Although both of these would be inferior to native scheduling. |
| 543 | schedulePerformWorkUntilDeadline = () => { |
| 544 | localSetImmediate(performWorkUntilDeadline); |
| 545 | }; |
| 546 | } else if (typeof MessageChannel !== 'undefined') { |
| 547 | // DOM and Worker environments. |
| 548 | // We prefer MessageChannel because of the 4ms setTimeout clamping. |
| 549 | const channel = new MessageChannel(); |
| 550 | const port = channel.port2; |
| 551 | channel.port1.onmessage = performWorkUntilDeadline; |
| 552 | schedulePerformWorkUntilDeadline = () => { |
| 553 | port.postMessage(null); |
| 554 | }; |
| 555 | } else { |
| 556 | // We should only fallback here in non-browser environments. |
| 557 | schedulePerformWorkUntilDeadline = () => { |
| 558 | // $FlowFixMe[not-a-function] nullable value |
| 559 | localSetTimeout(performWorkUntilDeadline, 0); |
| 560 | }; |
| 561 | } |
| 562 | |
| 563 | function requestHostCallback() { |
| 564 | if (!isMessageLoopRunning) { |
| 565 | isMessageLoopRunning = true; |
| 566 | schedulePerformWorkUntilDeadline(); |
| 567 | } |
| 568 | } |
| 569 | |
| 570 | function requestHostTimeout( |
| 571 | callback: (currentTime: number) => void, |
| 572 | ms: number, |
| 573 | ) { |
| 574 | // $FlowFixMe[not-a-function] nullable value |
| 575 | taskTimeoutID = localSetTimeout(() => { |
| 576 | callback(getCurrentTime()); |
| 577 | }, ms); |
| 578 | } |
| 579 | |
| 580 | function cancelHostTimeout() { |
| 581 | // $FlowFixMe[not-a-function] nullable value |
| 582 | localClearTimeout(taskTimeoutID); |
| 583 | taskTimeoutID = -1 as any as TimeoutID; |
| 584 | } |
| 585 | |
| 586 | export { |
| 587 | ImmediatePriority as unstable_ImmediatePriority, |
| 588 | UserBlockingPriority as unstable_UserBlockingPriority, |
| 589 | NormalPriority as unstable_NormalPriority, |
| 590 | IdlePriority as unstable_IdlePriority, |
| 591 | LowPriority as unstable_LowPriority, |
| 592 | unstable_runWithPriority, |
| 593 | unstable_next, |
| 594 | unstable_scheduleCallback, |
| 595 | unstable_cancelCallback, |
| 596 | unstable_wrapCallback, |
| 597 | unstable_getCurrentPriorityLevel, |
| 598 | shouldYieldToHost as unstable_shouldYield, |
| 599 | requestPaint as unstable_requestPaint, |
| 600 | getCurrentTime as unstable_now, |
| 601 | forceFrameRate as unstable_forceFrameRate, |
| 602 | }; |
| 603 | |
| 604 | export const unstable_Profiling: { |
| 605 | startLoggingProfilingEvents(): void, |
| 606 | stopLoggingProfilingEvents(): ArrayBuffer | null, |
| 607 | // $FlowFixMe[constant-condition] |
| 608 | } | null = enableProfiling |
| 609 | ? { |
| 610 | startLoggingProfilingEvents, |
| 611 | stopLoggingProfilingEvents, |
| 612 | } |
| 613 | : null; |