-
Notifications
You must be signed in to change notification settings - Fork 46.4k
/
ReactFiberWorkLoop.js
2748 lines (2500 loc) · 94.2 KB
/
ReactFiberWorkLoop.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
*/
import type {Fiber} from './ReactFiber';
import type {FiberRoot} from './ReactFiberRoot';
import type {ExpirationTime} from './ReactFiberExpirationTime';
import type {
ReactPriorityLevel,
SchedulerCallback,
} from './SchedulerWithReactIntegration';
import type {Interaction} from 'scheduler/src/Tracing';
import type {SuspenseConfig} from './ReactFiberSuspenseConfig';
import {
warnAboutDeprecatedLifecycles,
enableUserTimingAPI,
enableSuspenseServerRenderer,
replayFailedUnitOfWorkWithInvokeGuardedCallback,
enableProfilerTimer,
enableSchedulerTracing,
revertPassiveEffectsChange,
} from 'shared/ReactFeatureFlags';
import ReactSharedInternals from 'shared/ReactSharedInternals';
import invariant from 'shared/invariant';
import warning from 'shared/warning';
import {
scheduleCallback,
cancelCallback,
getCurrentPriorityLevel,
runWithPriority,
shouldYield,
requestPaint,
now,
ImmediatePriority,
UserBlockingPriority,
NormalPriority,
LowPriority,
IdlePriority,
flushSyncCallbackQueue,
scheduleSyncCallback,
} from './SchedulerWithReactIntegration';
import {__interactionsRef, __subscriberRef} from 'scheduler/tracing';
import {
prepareForCommit,
resetAfterCommit,
scheduleTimeout,
cancelTimeout,
noTimeout,
warnsIfNotActing,
} from './ReactFiberHostConfig';
import {createWorkInProgress, assignFiberPropertiesInDEV} from './ReactFiber';
import {
NoMode,
StrictMode,
ProfileMode,
BatchedMode,
ConcurrentMode,
} from './ReactTypeOfMode';
import {
HostRoot,
ClassComponent,
SuspenseComponent,
DehydratedSuspenseComponent,
FunctionComponent,
ForwardRef,
MemoComponent,
SimpleMemoComponent,
} from 'shared/ReactWorkTags';
import {
NoEffect,
PerformedWork,
Placement,
Update,
PlacementAndUpdate,
Deletion,
Ref,
ContentReset,
Snapshot,
Callback,
Passive,
Incomplete,
HostEffectMask,
} from 'shared/ReactSideEffectTags';
import {
NoWork,
Sync,
Never,
msToExpirationTime,
expirationTimeToMs,
computeInteractiveExpiration,
computeAsyncExpiration,
computeSuspenseExpiration,
inferPriorityFromExpirationTime,
LOW_PRIORITY_EXPIRATION,
Batched,
} from './ReactFiberExpirationTime';
import {beginWork as originalBeginWork} from './ReactFiberBeginWork';
import {completeWork} from './ReactFiberCompleteWork';
import {unwindWork, unwindInterruptedWork} from './ReactFiberUnwindWork';
import {
throwException,
createRootErrorUpdate,
createClassErrorUpdate,
} from './ReactFiberThrow';
import {
commitBeforeMutationLifeCycles as commitBeforeMutationEffectOnFiber,
commitLifeCycles as commitLayoutEffectOnFiber,
commitPassiveHookEffects,
commitPlacement,
commitWork,
commitDeletion,
commitDetachRef,
commitAttachRef,
commitResetTextContent,
} from './ReactFiberCommitWork';
import {enqueueUpdate} from './ReactUpdateQueue';
import {resetContextDependencies} from './ReactFiberNewContext';
import {resetHooks, ContextOnlyDispatcher} from './ReactFiberHooks';
import {createCapturedValue} from './ReactCapturedValue';
import {
recordCommitTime,
startProfilerTimer,
stopProfilerTimerIfRunningAndRecordDelta,
} from './ReactProfilerTimer';
// DEV stuff
import warningWithoutStack from 'shared/warningWithoutStack';
import getComponentName from 'shared/getComponentName';
import ReactStrictModeWarnings from './ReactStrictModeWarnings';
import {
phase as ReactCurrentDebugFiberPhaseInDEV,
resetCurrentFiber as resetCurrentDebugFiberInDEV,
setCurrentFiber as setCurrentDebugFiberInDEV,
getStackByFiberInDevAndProd,
} from './ReactCurrentFiber';
import {
recordEffect,
recordScheduleUpdate,
startRequestCallbackTimer,
stopRequestCallbackTimer,
startWorkTimer,
stopWorkTimer,
stopFailedWorkTimer,
startWorkLoopTimer,
stopWorkLoopTimer,
startCommitTimer,
stopCommitTimer,
startCommitSnapshotEffectsTimer,
stopCommitSnapshotEffectsTimer,
startCommitHostEffectsTimer,
stopCommitHostEffectsTimer,
startCommitLifeCyclesTimer,
stopCommitLifeCyclesTimer,
} from './ReactDebugFiberPerf';
import {
invokeGuardedCallback,
hasCaughtError,
clearCaughtError,
} from 'shared/ReactErrorUtils';
import {onCommitRoot} from './ReactFiberDevToolsHook';
const ceil = Math.ceil;
const {
ReactCurrentDispatcher,
ReactCurrentOwner,
IsSomeRendererActing,
} = ReactSharedInternals;
type ExecutionContext = number;
const NoContext = /* */ 0b000000;
const BatchedContext = /* */ 0b000001;
const EventContext = /* */ 0b000010;
const DiscreteEventContext = /* */ 0b000100;
const LegacyUnbatchedContext = /* */ 0b001000;
const RenderContext = /* */ 0b010000;
const CommitContext = /* */ 0b100000;
type RootExitStatus = 0 | 1 | 2 | 3 | 4;
const RootIncomplete = 0;
const RootErrored = 1;
const RootSuspended = 2;
const RootSuspendedWithDelay = 3;
const RootCompleted = 4;
export type Thenable = {
then(resolve: () => mixed, reject?: () => mixed): Thenable | void,
};
// Describes where we are in the React execution stack
let executionContext: ExecutionContext = NoContext;
// The root we're working on
let workInProgressRoot: FiberRoot | null = null;
// The fiber we're working on
let workInProgress: Fiber | null = null;
// The expiration time we're rendering
let renderExpirationTime: ExpirationTime = NoWork;
// Whether to root completed, errored, suspended, etc.
let workInProgressRootExitStatus: RootExitStatus = RootIncomplete;
// Most recent event time among processed updates during this render.
// This is conceptually a time stamp but expressed in terms of an ExpirationTime
// because we deal mostly with expiration times in the hot path, so this avoids
// the conversion happening in the hot path.
let workInProgressRootLatestProcessedExpirationTime: ExpirationTime = Sync;
let workInProgressRootLatestSuspenseTimeout: ExpirationTime = Sync;
let workInProgressRootCanSuspendUsingConfig: null | SuspenseConfig = null;
// If we're pinged while rendering we don't always restart immediately.
// This flag determines if it might be worthwhile to restart if an opportunity
// happens latere.
let workInProgressRootHasPendingPing: boolean = false;
// The most recent time we committed a fallback. This lets us ensure a train
// model where we don't commit new loading states in too quick succession.
let globalMostRecentFallbackTime: number = 0;
const FALLBACK_THROTTLE_MS: number = 500;
let nextEffect: Fiber | null = null;
let hasUncaughtError = false;
let firstUncaughtError = null;
let legacyErrorBoundariesThatAlreadyFailed: Set<mixed> | null = null;
let rootDoesHavePassiveEffects: boolean = false;
let rootWithPendingPassiveEffects: FiberRoot | null = null;
let pendingPassiveEffectsExpirationTime: ExpirationTime = NoWork;
let rootsWithPendingDiscreteUpdates: Map<
FiberRoot,
ExpirationTime,
> | null = null;
// Use these to prevent an infinite loop of nested updates
const NESTED_UPDATE_LIMIT = 50;
let nestedUpdateCount: number = 0;
let rootWithNestedUpdates: FiberRoot | null = null;
const NESTED_PASSIVE_UPDATE_LIMIT = 50;
let nestedPassiveUpdateCount: number = 0;
let interruptedBy: Fiber | null = null;
// Marks the need to reschedule pending interactions at these expiration times
// during the commit phase. This enables them to be traced across components
// that spawn new work during render. E.g. hidden boundaries, suspended SSR
// hydration or SuspenseList.
let spawnedWorkDuringRender: null | Array<ExpirationTime> = null;
// Expiration times are computed by adding to the current time (the start
// time). However, if two updates are scheduled within the same event, we
// should treat their start times as simultaneous, even if the actual clock
// time has advanced between the first and second call.
// In other words, because expiration times determine how updates are batched,
// we want all updates of like priority that occur within the same event to
// receive the same expiration time. Otherwise we get tearing.
let currentEventTime: ExpirationTime = NoWork;
export function requestCurrentTime() {
if ((executionContext & (RenderContext | CommitContext)) !== NoContext) {
// We're inside React, so it's fine to read the actual time.
return msToExpirationTime(now());
}
// We're not inside React, so we may be in the middle of a browser event.
if (currentEventTime !== NoWork) {
// Use the same start time for all updates until we enter React again.
return currentEventTime;
}
// This is the first update since React yielded. Compute a new start time.
currentEventTime = msToExpirationTime(now());
return currentEventTime;
}
export function computeExpirationForFiber(
currentTime: ExpirationTime,
fiber: Fiber,
suspenseConfig: null | SuspenseConfig,
): ExpirationTime {
const mode = fiber.mode;
if ((mode & BatchedMode) === NoMode) {
return Sync;
}
const priorityLevel = getCurrentPriorityLevel();
if ((mode & ConcurrentMode) === NoMode) {
return priorityLevel === ImmediatePriority ? Sync : Batched;
}
if ((executionContext & RenderContext) !== NoContext) {
// Use whatever time we're already rendering
return renderExpirationTime;
}
let expirationTime;
if (suspenseConfig !== null) {
// Compute an expiration time based on the Suspense timeout.
expirationTime = computeSuspenseExpiration(
currentTime,
suspenseConfig.timeoutMs | 0 || LOW_PRIORITY_EXPIRATION,
);
} else {
// Compute an expiration time based on the Scheduler priority.
switch (priorityLevel) {
case ImmediatePriority:
expirationTime = Sync;
break;
case UserBlockingPriority:
// TODO: Rename this to computeUserBlockingExpiration
expirationTime = computeInteractiveExpiration(currentTime);
break;
case NormalPriority:
case LowPriority: // TODO: Handle LowPriority
// TODO: Rename this to... something better.
expirationTime = computeAsyncExpiration(currentTime);
break;
case IdlePriority:
expirationTime = Never;
break;
default:
invariant(false, 'Expected a valid priority level');
}
}
// If we're in the middle of rendering a tree, do not update at the same
// expiration time that is already rendering.
// TODO: We shouldn't have to do this if the update is on a different root.
// Refactor computeExpirationForFiber + scheduleUpdate so we have access to
// the root when we check for this condition.
if (workInProgressRoot !== null && expirationTime === renderExpirationTime) {
// This is a trick to move this update into a separate batch
expirationTime -= 1;
}
return expirationTime;
}
let lastUniqueAsyncExpiration = NoWork;
export function computeUniqueAsyncExpiration(): ExpirationTime {
const currentTime = requestCurrentTime();
let result = computeAsyncExpiration(currentTime);
if (result <= lastUniqueAsyncExpiration) {
// Since we assume the current time monotonically increases, we only hit
// this branch when computeUniqueAsyncExpiration is fired multiple times
// within a 200ms window (or whatever the async bucket size is).
result -= 1;
}
lastUniqueAsyncExpiration = result;
return result;
}
export function scheduleUpdateOnFiber(
fiber: Fiber,
expirationTime: ExpirationTime,
) {
checkForNestedUpdates();
warnAboutInvalidUpdatesOnClassComponentsInDEV(fiber);
const root = markUpdateTimeFromFiberToRoot(fiber, expirationTime);
if (root === null) {
warnAboutUpdateOnUnmountedFiberInDEV(fiber);
return;
}
root.pingTime = NoWork;
checkForInterruption(fiber, expirationTime);
recordScheduleUpdate();
// TODO: computeExpirationForFiber also reads the priority. Pass the
// priority as an argument to that function and this one.
const priorityLevel = getCurrentPriorityLevel();
if (expirationTime === Sync) {
if (
// Check if we're inside unbatchedUpdates
(executionContext & LegacyUnbatchedContext) !== NoContext &&
// Check if we're not already rendering
(executionContext & (RenderContext | CommitContext)) === NoContext
) {
// Register pending interactions on the root to avoid losing traced interaction data.
schedulePendingInteractions(root, expirationTime);
// This is a legacy edge case. The initial mount of a ReactDOM.render-ed
// root inside of batchedUpdates should be synchronous, but layout updates
// should be deferred until the end of the batch.
let callback = renderRoot(root, Sync, true);
while (callback !== null) {
callback = callback(true);
}
} else {
scheduleCallbackForRoot(root, ImmediatePriority, Sync);
if (executionContext === NoContext) {
// Flush the synchronous work now, wnless we're already working or inside
// a batch. This is intentionally inside scheduleUpdateOnFiber instead of
// scheduleCallbackForFiber to preserve the ability to schedule a callback
// without immediately flushing it. We only do this for user-initiated
// updates, to preserve historical behavior of sync mode.
flushSyncCallbackQueue();
}
}
} else {
scheduleCallbackForRoot(root, priorityLevel, expirationTime);
}
if (
(executionContext & DiscreteEventContext) !== NoContext &&
// Only updates at user-blocking priority or greater are considered
// discrete, even inside a discrete event.
(priorityLevel === UserBlockingPriority ||
priorityLevel === ImmediatePriority)
) {
// This is the result of a discrete event. Track the lowest priority
// discrete update per root so we can flush them early, if needed.
if (rootsWithPendingDiscreteUpdates === null) {
rootsWithPendingDiscreteUpdates = new Map([[root, expirationTime]]);
} else {
const lastDiscreteTime = rootsWithPendingDiscreteUpdates.get(root);
if (lastDiscreteTime === undefined || lastDiscreteTime > expirationTime) {
rootsWithPendingDiscreteUpdates.set(root, expirationTime);
}
}
}
}
export const scheduleWork = scheduleUpdateOnFiber;
// This is split into a separate function so we can mark a fiber with pending
// work without treating it as a typical update that originates from an event;
// e.g. retrying a Suspense boundary isn't an update, but it does schedule work
// on a fiber.
function markUpdateTimeFromFiberToRoot(fiber, expirationTime) {
// Update the source fiber's expiration time
if (fiber.expirationTime < expirationTime) {
fiber.expirationTime = expirationTime;
}
let alternate = fiber.alternate;
if (alternate !== null && alternate.expirationTime < expirationTime) {
alternate.expirationTime = expirationTime;
}
// Walk the parent path to the root and update the child expiration time.
let node = fiber.return;
let root = null;
if (node === null && fiber.tag === HostRoot) {
root = fiber.stateNode;
} else {
while (node !== null) {
alternate = node.alternate;
if (node.childExpirationTime < expirationTime) {
node.childExpirationTime = expirationTime;
if (
alternate !== null &&
alternate.childExpirationTime < expirationTime
) {
alternate.childExpirationTime = expirationTime;
}
} else if (
alternate !== null &&
alternate.childExpirationTime < expirationTime
) {
alternate.childExpirationTime = expirationTime;
}
if (node.return === null && node.tag === HostRoot) {
root = node.stateNode;
break;
}
node = node.return;
}
}
if (root !== null) {
// Update the first and last pending expiration times in this root
const firstPendingTime = root.firstPendingTime;
if (expirationTime > firstPendingTime) {
root.firstPendingTime = expirationTime;
}
const lastPendingTime = root.lastPendingTime;
if (lastPendingTime === NoWork || expirationTime < lastPendingTime) {
root.lastPendingTime = expirationTime;
}
}
return root;
}
// Use this function, along with runRootCallback, to ensure that only a single
// callback per root is scheduled. It's still possible to call renderRoot
// directly, but scheduling via this function helps avoid excessive callbacks.
// It works by storing the callback node and expiration time on the root. When a
// new callback comes in, it compares the expiration time to determine if it
// should cancel the previous one. It also relies on commitRoot scheduling a
// callback to render the next level, because that means we don't need a
// separate callback per expiration time.
function scheduleCallbackForRoot(
root: FiberRoot,
priorityLevel: ReactPriorityLevel,
expirationTime: ExpirationTime,
) {
const existingCallbackExpirationTime = root.callbackExpirationTime;
if (existingCallbackExpirationTime < expirationTime) {
// New callback has higher priority than the existing one.
const existingCallbackNode = root.callbackNode;
if (existingCallbackNode !== null) {
cancelCallback(existingCallbackNode);
}
root.callbackExpirationTime = expirationTime;
if (expirationTime === Sync) {
// Sync React callbacks are scheduled on a special internal queue
root.callbackNode = scheduleSyncCallback(
runRootCallback.bind(
null,
root,
renderRoot.bind(null, root, expirationTime),
),
);
} else {
let options = null;
if (expirationTime !== Never) {
let timeout = expirationTimeToMs(expirationTime) - now();
options = {timeout};
}
root.callbackNode = scheduleCallback(
priorityLevel,
runRootCallback.bind(
null,
root,
renderRoot.bind(null, root, expirationTime),
),
options,
);
if (
enableUserTimingAPI &&
expirationTime !== Sync &&
(executionContext & (RenderContext | CommitContext)) === NoContext
) {
// Scheduled an async callback, and we're not already working. Add an
// entry to the flamegraph that shows we're waiting for a callback
// to fire.
startRequestCallbackTimer();
}
}
}
// Associate the current interactions with this new root+priority.
schedulePendingInteractions(root, expirationTime);
}
function runRootCallback(root, callback, isSync) {
const prevCallbackNode = root.callbackNode;
let continuation = null;
try {
continuation = callback(isSync);
if (continuation !== null) {
return runRootCallback.bind(null, root, continuation);
} else {
return null;
}
} finally {
// If the callback exits without returning a continuation, remove the
// corresponding callback node from the root. Unless the callback node
// has changed, which implies that it was already cancelled by a high
// priority update.
if (continuation === null && prevCallbackNode === root.callbackNode) {
root.callbackNode = null;
root.callbackExpirationTime = NoWork;
}
}
}
export function flushRoot(root: FiberRoot, expirationTime: ExpirationTime) {
if ((executionContext & (RenderContext | CommitContext)) !== NoContext) {
invariant(
false,
'work.commit(): Cannot commit while already rendering. This likely ' +
'means you attempted to commit from inside a lifecycle method.',
);
}
scheduleSyncCallback(renderRoot.bind(null, root, expirationTime));
flushSyncCallbackQueue();
}
export function flushDiscreteUpdates() {
// TODO: Should be able to flush inside batchedUpdates, but not inside `act`.
// However, `act` uses `batchedUpdates`, so there's no way to distinguish
// those two cases. Need to fix this before exposing flushDiscreteUpdates
// as a public API.
if (
(executionContext & (BatchedContext | RenderContext | CommitContext)) !==
NoContext
) {
if (__DEV__ && (executionContext & RenderContext) !== NoContext) {
warning(
false,
'unstable_flushDiscreteUpdates: Cannot flush updates when React is ' +
'already rendering.',
);
}
// We're already rendering, so we can't synchronously flush pending work.
// This is probably a nested event dispatch triggered by a lifecycle/effect,
// like `el.focus()`. Exit.
return;
}
flushPendingDiscreteUpdates();
if (!revertPassiveEffectsChange) {
// If the discrete updates scheduled passive effects, flush them now so that
// they fire before the next serial event.
flushPassiveEffects();
}
}
function resolveLocksOnRoot(root: FiberRoot, expirationTime: ExpirationTime) {
const firstBatch = root.firstBatch;
if (
firstBatch !== null &&
firstBatch._defer &&
firstBatch._expirationTime >= expirationTime
) {
scheduleCallback(NormalPriority, () => {
firstBatch._onComplete();
return null;
});
return true;
} else {
return false;
}
}
export function deferredUpdates<A>(fn: () => A): A {
// TODO: Remove in favor of Scheduler.next
return runWithPriority(NormalPriority, fn);
}
export function syncUpdates<A, B, C, R>(
fn: (A, B, C) => R,
a: A,
b: B,
c: C,
): R {
return runWithPriority(ImmediatePriority, fn.bind(null, a, b, c));
}
function flushPendingDiscreteUpdates() {
if (rootsWithPendingDiscreteUpdates !== null) {
// For each root with pending discrete updates, schedule a callback to
// immediately flush them.
const roots = rootsWithPendingDiscreteUpdates;
rootsWithPendingDiscreteUpdates = null;
roots.forEach((expirationTime, root) => {
scheduleSyncCallback(renderRoot.bind(null, root, expirationTime));
});
// Now flush the immediate queue.
flushSyncCallbackQueue();
}
}
export function batchedUpdates<A, R>(fn: A => R, a: A): R {
const prevExecutionContext = executionContext;
executionContext |= BatchedContext;
try {
return fn(a);
} finally {
executionContext = prevExecutionContext;
if (executionContext === NoContext) {
// Flush the immediate callbacks that were scheduled during this batch
flushSyncCallbackQueue();
}
}
}
export function batchedEventUpdates<A, R>(fn: A => R, a: A): R {
const prevExecutionContext = executionContext;
executionContext |= EventContext;
try {
return fn(a);
} finally {
executionContext = prevExecutionContext;
if (executionContext === NoContext) {
// Flush the immediate callbacks that were scheduled during this batch
flushSyncCallbackQueue();
}
}
}
export function discreteUpdates<A, B, C, R>(
fn: (A, B, C) => R,
a: A,
b: B,
c: C,
): R {
const prevExecutionContext = executionContext;
executionContext |= DiscreteEventContext;
try {
// Should this
return runWithPriority(UserBlockingPriority, fn.bind(null, a, b, c));
} finally {
executionContext = prevExecutionContext;
if (executionContext === NoContext) {
// Flush the immediate callbacks that were scheduled during this batch
flushSyncCallbackQueue();
}
}
}
export function unbatchedUpdates<A, R>(fn: (a: A) => R, a: A): R {
const prevExecutionContext = executionContext;
executionContext &= ~BatchedContext;
executionContext |= LegacyUnbatchedContext;
try {
return fn(a);
} finally {
executionContext = prevExecutionContext;
if (executionContext === NoContext) {
// Flush the immediate callbacks that were scheduled during this batch
flushSyncCallbackQueue();
}
}
}
export function flushSync<A, R>(fn: A => R, a: A): R {
if ((executionContext & (RenderContext | CommitContext)) !== NoContext) {
invariant(
false,
'flushSync was called from inside a lifecycle method. It cannot be ' +
'called when React is already rendering.',
);
}
const prevExecutionContext = executionContext;
executionContext |= BatchedContext;
try {
return runWithPriority(ImmediatePriority, fn.bind(null, a));
} finally {
executionContext = prevExecutionContext;
// Flush the immediate callbacks that were scheduled during this batch.
// Note that this will happen even if batchedUpdates is higher up
// the stack.
flushSyncCallbackQueue();
}
}
export function flushControlled(fn: () => mixed): void {
const prevExecutionContext = executionContext;
executionContext |= BatchedContext;
try {
runWithPriority(ImmediatePriority, fn);
} finally {
executionContext = prevExecutionContext;
if (executionContext === NoContext) {
// Flush the immediate callbacks that were scheduled during this batch
flushSyncCallbackQueue();
}
}
}
function prepareFreshStack(root, expirationTime) {
root.finishedWork = null;
root.finishedExpirationTime = NoWork;
const timeoutHandle = root.timeoutHandle;
if (timeoutHandle !== noTimeout) {
// The root previous suspended and scheduled a timeout to commit a fallback
// state. Now that we have additional work, cancel the timeout.
root.timeoutHandle = noTimeout;
// $FlowFixMe Complains noTimeout is not a TimeoutID, despite the check above
cancelTimeout(timeoutHandle);
}
if (workInProgress !== null) {
let interruptedWork = workInProgress.return;
while (interruptedWork !== null) {
unwindInterruptedWork(interruptedWork);
interruptedWork = interruptedWork.return;
}
}
workInProgressRoot = root;
workInProgress = createWorkInProgress(root.current, null, expirationTime);
renderExpirationTime = expirationTime;
workInProgressRootExitStatus = RootIncomplete;
workInProgressRootLatestProcessedExpirationTime = Sync;
workInProgressRootLatestSuspenseTimeout = Sync;
workInProgressRootCanSuspendUsingConfig = null;
workInProgressRootHasPendingPing = false;
if (enableSchedulerTracing) {
spawnedWorkDuringRender = null;
}
if (__DEV__) {
ReactStrictModeWarnings.discardPendingWarnings();
componentsWithSuspendedDiscreteUpdates = null;
}
}
function renderRoot(
root: FiberRoot,
expirationTime: ExpirationTime,
isSync: boolean,
): SchedulerCallback | null {
invariant(
(executionContext & (RenderContext | CommitContext)) === NoContext,
'Should not already be working.',
);
if (enableUserTimingAPI && expirationTime !== Sync) {
const didExpire = isSync;
stopRequestCallbackTimer(didExpire);
}
if (root.firstPendingTime < expirationTime) {
// If there's no work left at this expiration time, exit immediately. This
// happens when multiple callbacks are scheduled for a single root, but an
// earlier callback flushes the work of a later one.
return null;
}
if (isSync && root.finishedExpirationTime === expirationTime) {
// There's already a pending commit at this expiration time.
// TODO: This is poorly factored. This case only exists for the
// batch.commit() API.
return commitRoot.bind(null, root);
}
flushPassiveEffects();
// If the root or expiration time have changed, throw out the existing stack
// and prepare a fresh one. Otherwise we'll continue where we left off.
if (root !== workInProgressRoot || expirationTime !== renderExpirationTime) {
prepareFreshStack(root, expirationTime);
startWorkOnPendingInteractions(root, expirationTime);
} else if (workInProgressRootExitStatus === RootSuspendedWithDelay) {
// We could've received an update at a lower priority while we yielded.
// We're suspended in a delayed state. Once we complete this render we're
// just going to try to recover at the last pending time anyway so we might
// as well start doing that eagerly.
// Ideally we should be able to do this even for retries but we don't yet
// know if we're going to process an update which wants to commit earlier,
// and this path happens very early so it would happen too often. Instead,
// for that case, we'll wait until we complete.
if (workInProgressRootHasPendingPing) {
// We have a ping at this expiration. Let's restart to see if we get unblocked.
prepareFreshStack(root, expirationTime);
} else {
const lastPendingTime = root.lastPendingTime;
if (lastPendingTime < expirationTime) {
// There's lower priority work. It might be unsuspended. Try rendering
// at that level immediately, while preserving the position in the queue.
return renderRoot.bind(null, root, lastPendingTime);
}
}
}
// If we have a work-in-progress fiber, it means there's still work to do
// in this root.
if (workInProgress !== null) {
const prevExecutionContext = executionContext;
executionContext |= RenderContext;
let prevDispatcher = ReactCurrentDispatcher.current;
if (prevDispatcher === null) {
// The React isomorphic package does not include a default dispatcher.
// Instead the first renderer will lazily attach one, in order to give
// nicer error messages.
prevDispatcher = ContextOnlyDispatcher;
}
ReactCurrentDispatcher.current = ContextOnlyDispatcher;
let prevInteractions: Set<Interaction> | null = null;
if (enableSchedulerTracing) {
prevInteractions = __interactionsRef.current;
__interactionsRef.current = root.memoizedInteractions;
}
startWorkLoopTimer(workInProgress);
// TODO: Fork renderRoot into renderRootSync and renderRootAsync
if (isSync) {
if (expirationTime !== Sync) {
// An async update expired. There may be other expired updates on
// this root. We should render all the expired work in a
// single batch.
const currentTime = requestCurrentTime();
if (currentTime < expirationTime) {
// Restart at the current time.
executionContext = prevExecutionContext;
resetContextDependencies();
ReactCurrentDispatcher.current = prevDispatcher;
if (enableSchedulerTracing) {
__interactionsRef.current = ((prevInteractions: any): Set<
Interaction,
>);
}
return renderRoot.bind(null, root, currentTime);
}
}
} else {
// Since we know we're in a React event, we can clear the current
// event time. The next update will compute a new event time.
currentEventTime = NoWork;
}
do {
try {
if (isSync) {
workLoopSync();
} else {
workLoop();
}
break;
} catch (thrownValue) {
// Reset module-level state that was set during the render phase.
resetContextDependencies();
resetHooks();
const sourceFiber = workInProgress;
if (sourceFiber === null || sourceFiber.return === null) {
// Expected to be working on a non-root fiber. This is a fatal error
// because there's no ancestor that can handle it; the root is
// supposed to capture all errors that weren't caught by an error
// boundary.
prepareFreshStack(root, expirationTime);
executionContext = prevExecutionContext;
throw thrownValue;
}
if (enableProfilerTimer && sourceFiber.mode & ProfileMode) {
// Record the time spent rendering before an error was thrown. This
// avoids inaccurate Profiler durations in the case of a
// suspended render.
stopProfilerTimerIfRunningAndRecordDelta(sourceFiber, true);
}
const returnFiber = sourceFiber.return;
throwException(
root,
returnFiber,
sourceFiber,
thrownValue,
renderExpirationTime,
);
workInProgress = completeUnitOfWork(sourceFiber);
}
} while (true);
executionContext = prevExecutionContext;
resetContextDependencies();
ReactCurrentDispatcher.current = prevDispatcher;
if (enableSchedulerTracing) {
__interactionsRef.current = ((prevInteractions: any): Set<Interaction>);
}
if (workInProgress !== null) {
// There's still work left over. Return a continuation.
stopInterruptedWorkLoopTimer();
if (expirationTime !== Sync) {
startRequestCallbackTimer();
}
return renderRoot.bind(null, root, expirationTime);
}
}
// We now have a consistent tree. The next step is either to commit it, or, if
// something suspended, wait to commit it after a timeout.
stopFinishedWorkLoopTimer();
root.finishedWork = root.current.alternate;
root.finishedExpirationTime = expirationTime;
const isLocked = resolveLocksOnRoot(root, expirationTime);
if (isLocked) {
// This root has a lock that prevents it from committing. Exit. If we begin
// work on the root again, without any intervening updates, it will finish
// without doing additional work.
return null;
}
// Set this to null to indicate there's no in-progress render.
workInProgressRoot = null;
switch (workInProgressRootExitStatus) {
case RootIncomplete: {
invariant(false, 'Should have a work-in-progress.');
}
// Flow knows about invariant, so it compains if I add a break statement,
// but eslint doesn't know about invariant, so it complains if I do.
// eslint-disable-next-line no-fallthrough
case RootErrored: {
// An error was thrown. First check if there is lower priority work
// scheduled on this root.
const lastPendingTime = root.lastPendingTime;
if (lastPendingTime < expirationTime) {
// There's lower priority work. Before raising the error, try rendering
// at the lower priority to see if it fixes it. Use a continuation to
// maintain the existing priority and position in the queue.
return renderRoot.bind(null, root, lastPendingTime);