Best JavaScript code snippet using playwright-internal
ReactFiberWorkLoop.js
Source:ReactFiberWorkLoop.js  
...655        stopInterruptedWorkLoopTimer();656      } else {657        // We now have a consistent tree. The next step is either to commit it,658        // or, if something suspended, wait to commit it after a timeout.659        stopFinishedWorkLoopTimer();660        const finishedWork: Fiber = ((root.finishedWork =661          root.current.alternate): any);662        root.finishedExpirationTime = expirationTime;663        finishConcurrentRender(664          root,665          finishedWork,666          workInProgressRootExitStatus,667          expirationTime,668        );669      }670      ensureRootIsScheduled(root);671      if (root.callbackNode === originalCallbackNode) {672        // The task node scheduled for this root is the same one that's673        // currently executed. Need to return a continuation.674        return performConcurrentWorkOnRoot.bind(null, root);675      }676    }677  }678  return null;679}680function finishConcurrentRender(681  root,682  finishedWork,683  exitStatus,684  expirationTime,685) {686  // Set this to null to indicate there's no in-progress render.687  workInProgressRoot = null;688  switch (exitStatus) {689    case RootIncomplete:690    case RootFatalErrored: {691      invariant(false, 'Root did not complete. This is a bug in React.');692    }693    // Flow knows about invariant, so it complains if I add a break694    // statement, but eslint doesn't know about invariant, so it complains695    // if I do. eslint-disable-next-line no-fallthrough696    case RootErrored: {697      // If this was an async render, the error may have happened due to698      // a mutation in a concurrent event. Try rendering one more time,699      // synchronously, to see if the error goes away. If there are700      // lower priority updates, let's include those, too, in case they701      // fix the inconsistency. Render at Idle to include all updates.702      // If it was Idle or Never or some not-yet-invented time, render703      // at that time.704      markRootExpiredAtTime(705        root,706        expirationTime > Idle ? Idle : expirationTime,707      );708      // We assume that this second render pass will be synchronous709      // and therefore not hit this path again.710      break;711    }712    case RootSuspended: {713      markRootSuspendedAtTime(root, expirationTime);714      const lastSuspendedTime = root.lastSuspendedTime;715      if (expirationTime === lastSuspendedTime) {716        root.nextKnownPendingLevel = getRemainingExpirationTime(finishedWork);717      }718      // We have an acceptable loading state. We need to figure out if we719      // should immediately commit it or wait a bit.720      // If we have processed new updates during this render, we may now721      // have a new loading state ready. We want to ensure that we commit722      // that as soon as possible.723      const hasNotProcessedNewUpdates =724        workInProgressRootLatestProcessedExpirationTime === Sync;725      if (726        hasNotProcessedNewUpdates &&727        // do not delay if we're inside an act() scope728        !(729          true &&730          flushSuspenseFallbacksInTests &&731          IsThisRendererActing.current732        )733      ) {734        // If we have not processed any new updates during this pass, then735        // this is either a retry of an existing fallback state or a736        // hidden tree. Hidden trees shouldn't be batched with other work737        // and after that's fixed it can only be a retry. We're going to738        // throttle committing retries so that we don't show too many739        // loading states too quickly.740        let msUntilTimeout =741          globalMostRecentFallbackTime + FALLBACK_THROTTLE_MS - now();742        // Don't bother with a very short suspense time.743        if (msUntilTimeout > 10) {744          if (workInProgressRootHasPendingPing) {745            const lastPingedTime = root.lastPingedTime;746            if (lastPingedTime === NoWork || lastPingedTime >= expirationTime) {747              // This render was pinged but we didn't get to restart748              // earlier so try restarting now instead.749              root.lastPingedTime = expirationTime;750              prepareFreshStack(root, expirationTime);751              break;752            }753          }754          const nextTime = getNextRootExpirationTimeToWorkOn(root);755          if (nextTime !== NoWork && nextTime !== expirationTime) {756            // There's additional work on this root.757            break;758          }759          if (760            lastSuspendedTime !== NoWork &&761            lastSuspendedTime !== expirationTime762          ) {763            // We should prefer to render the fallback of at the last764            // suspended level. Ping the last suspended level to try765            // rendering it again.766            root.lastPingedTime = lastSuspendedTime;767            break;768          }769          // The render is suspended, it hasn't timed out, and there's no770          // lower priority work to do. Instead of committing the fallback771          // immediately, wait for more data to arrive.772          root.timeoutHandle = scheduleTimeout(773            commitRoot.bind(null, root),774            msUntilTimeout,775          );776          break;777        }778      }779      // The work expired. Commit immediately.780      commitRoot(root);781      break;782    }783    case RootSuspendedWithDelay: {784      markRootSuspendedAtTime(root, expirationTime);785      const lastSuspendedTime = root.lastSuspendedTime;786      if (expirationTime === lastSuspendedTime) {787        root.nextKnownPendingLevel = getRemainingExpirationTime(finishedWork);788      }789      if (790        // do not delay if we're inside an act() scope791        !(792          true &&793          flushSuspenseFallbacksInTests &&794          IsThisRendererActing.current795        )796      ) {797        // We're suspended in a state that should be avoided. We'll try to798        // avoid committing it for as long as the timeouts let us.799        if (workInProgressRootHasPendingPing) {800          const lastPingedTime = root.lastPingedTime;801          if (lastPingedTime === NoWork || lastPingedTime >= expirationTime) {802            // This render was pinged but we didn't get to restart earlier803            // so try restarting now instead.804            root.lastPingedTime = expirationTime;805            prepareFreshStack(root, expirationTime);806            break;807          }808        }809        const nextTime = getNextRootExpirationTimeToWorkOn(root);810        if (nextTime !== NoWork && nextTime !== expirationTime) {811          // There's additional work on this root.812          break;813        }814        if (815          lastSuspendedTime !== NoWork &&816          lastSuspendedTime !== expirationTime817        ) {818          // We should prefer to render the fallback of at the last819          // suspended level. Ping the last suspended level to try820          // rendering it again.821          root.lastPingedTime = lastSuspendedTime;822          break;823        }824        let msUntilTimeout;825        if (workInProgressRootLatestSuspenseTimeout !== Sync) {826          // We have processed a suspense config whose expiration time we827          // can use as the timeout.828          msUntilTimeout =829            expirationTimeToMs(workInProgressRootLatestSuspenseTimeout) - now();830        } else if (workInProgressRootLatestProcessedExpirationTime === Sync) {831          // This should never normally happen because only new updates832          // cause delayed states, so we should have processed something.833          // However, this could also happen in an offscreen tree.834          msUntilTimeout = 0;835        } else {836          // If we don't have a suspense config, we're going to use a837          // heuristic to determine how long we can suspend.838          const eventTimeMs: number = inferTimeFromExpirationTime(839            workInProgressRootLatestProcessedExpirationTime,840          );841          const currentTimeMs = now();842          const timeUntilExpirationMs =843            expirationTimeToMs(expirationTime) - currentTimeMs;844          let timeElapsed = currentTimeMs - eventTimeMs;845          if (timeElapsed < 0) {846            // We get this wrong some time since we estimate the time.847            timeElapsed = 0;848          }849          msUntilTimeout = jnd(timeElapsed) - timeElapsed;850          // Clamp the timeout to the expiration time. TODO: Once the851          // event time is exact instead of inferred from expiration time852          // we don't need this.853          if (timeUntilExpirationMs < msUntilTimeout) {854            msUntilTimeout = timeUntilExpirationMs;855          }856        }857        // Don't bother with a very short suspense time.858        if (msUntilTimeout > 10) {859          // The render is suspended, it hasn't timed out, and there's no860          // lower priority work to do. Instead of committing the fallback861          // immediately, wait for more data to arrive.862          root.timeoutHandle = scheduleTimeout(863            commitRoot.bind(null, root),864            msUntilTimeout,865          );866          break;867        }868      }869      // The work expired. Commit immediately.870      commitRoot(root);871      break;872    }873    case RootCompleted: {874      // The work completed. Ready to commit.875      if (876        // do not delay if we're inside an act() scope877        !(878          true &&879          flushSuspenseFallbacksInTests &&880          IsThisRendererActing.current881        ) &&882        workInProgressRootLatestProcessedExpirationTime !== Sync &&883        workInProgressRootCanSuspendUsingConfig !== null884      ) {885        // If we have exceeded the minimum loading delay, which probably886        // means we have shown a spinner already, we might have to suspend887        // a bit longer to ensure that the spinner is shown for888        // enough time.889        const msUntilTimeout = computeMsUntilSuspenseLoadingDelay(890          workInProgressRootLatestProcessedExpirationTime,891          expirationTime,892          workInProgressRootCanSuspendUsingConfig,893        );894        if (msUntilTimeout > 10) {895          markRootSuspendedAtTime(root, expirationTime);896          root.timeoutHandle = scheduleTimeout(897            commitRoot.bind(null, root),898            msUntilTimeout,899          );900          break;901        }902      }903      commitRoot(root);904      break;905    }906    default: {907      invariant(false, 'Unknown root exit status.');908    }909  }910}911// This is the entry point for synchronous tasks that don't go912// through Scheduler913function performSyncWorkOnRoot(root) {914  // Check if there's expired work on this root. Otherwise, render at Sync.915  const lastExpiredTime = root.lastExpiredTime;916  const expirationTime = lastExpiredTime !== NoWork ? lastExpiredTime : Sync;917  invariant(918    (executionContext & (RenderContext | CommitContext)) === NoContext,919    'Should not already be working.',920  );921  flushPassiveEffects();922  // If the root or expiration time have changed, throw out the existing stack923  // and prepare a fresh one. Otherwise we'll continue where we left off.924  if (root !== workInProgressRoot || expirationTime !== renderExpirationTime) {925    prepareFreshStack(root, expirationTime); // åå§å workInProgress926    startWorkOnPendingInteractions(root, expirationTime);927  }928  // If we have a work-in-progress fiber, it means there's still work to do929  // in this root.930  if (workInProgress !== null) {931    const prevExecutionContext = executionContext;932    executionContext |= RenderContext;933    const prevDispatcher = pushDispatcher(root);934    const prevInteractions = pushInteractions(root);935    startWorkLoopTimer(workInProgress);936    do {937      try {938        debugger939        workLoopSync();940        break;941      } catch (thrownValue) {942        handleError(root, thrownValue);943      }944    } while (true);945    resetContextDependencies();946    executionContext = prevExecutionContext;947    popDispatcher(prevDispatcher);948    if (enableSchedulerTracing) {949      popInteractions(((prevInteractions: any): Set<Interaction>));950    }951    if (workInProgressRootExitStatus === RootFatalErrored) {952      const fatalError = workInProgressRootFatalError;953      stopInterruptedWorkLoopTimer();954      prepareFreshStack(root, expirationTime);955      markRootSuspendedAtTime(root, expirationTime);956      ensureRootIsScheduled(root);957      throw fatalError;958    }959    if (workInProgress !== null) {960      // This is a sync render, so we should have finished the whole tree.961      invariant(962        false,963        'Cannot commit an incomplete root. This error is likely caused by a ' +964          'bug in React. Please file an issue.',965      );966    } else {967      // We now have a consistent tree. Because this is a sync render, we968      // will commit it even if something suspended.969      stopFinishedWorkLoopTimer();970      root.finishedWork = (root.current.alternate: any);971      root.finishedExpirationTime = expirationTime;972      finishSyncRender(root);973    }974    // Before exiting, make sure there's a callback scheduled for the next975    // pending level.976    ensureRootIsScheduled(root);977  }978  return null;979}980function finishSyncRender(root) {981  // Set this to null to indicate there's no in-progress render.982  workInProgressRoot = null;983  debugger;984  commitRoot(root);985}986export function flushRoot(root: FiberRoot, expirationTime: ExpirationTime) {987  markRootExpiredAtTime(root, expirationTime);988  ensureRootIsScheduled(root);989  if ((executionContext & (RenderContext | CommitContext)) === NoContext) {990    flushSyncCallbackQueue();991  }992}993export function flushDiscreteUpdates() {994  // TODO: Should be able to flush inside batchedUpdates, but not inside `act`.995  // However, `act` uses `batchedUpdates`, so there's no way to distinguish996  // those two cases. Need to fix this before exposing flushDiscreteUpdates997  // as a public API.998  if (999    (executionContext & (BatchedContext | RenderContext | CommitContext)) !==1000    NoContext1001  ) {1002    if (true) {1003      if ((executionContext & RenderContext) !== NoContext) {1004        console.error(1005          'unstable_flushDiscreteUpdates: Cannot flush updates when React is ' +1006            'already rendering.',1007        );1008      }1009    }1010    // We're already rendering, so we can't synchronously flush pending work.1011    // This is probably a nested event dispatch triggered by a lifecycle/effect,1012    // like `el.focus()`. Exit.1013    return;1014  }1015  flushPendingDiscreteUpdates();1016  // If the discrete updates scheduled passive effects, flush them now so that1017  // they fire before the next serial event.1018  flushPassiveEffects();1019}1020export function deferredUpdates<A>(fn: () => A): A {1021  // TODO: Remove in favor of Scheduler.next1022  return runWithPriority(NormalPriority, fn);1023}1024export function syncUpdates<A, B, C, R>(1025  fn: (A, B, C) => R,1026  a: A,1027  b: B,1028  c: C,1029): R {1030  return runWithPriority(ImmediatePriority, fn.bind(null, a, b, c));1031}1032function flushPendingDiscreteUpdates() {1033  if (rootsWithPendingDiscreteUpdates !== null) {1034    // For each root with pending discrete updates, schedule a callback to1035    // immediately flush them.1036    const roots = rootsWithPendingDiscreteUpdates;1037    rootsWithPendingDiscreteUpdates = null;1038    roots.forEach((expirationTime, root) => {1039      markRootExpiredAtTime(root, expirationTime);1040      ensureRootIsScheduled(root);1041    });1042    // Now flush the immediate queue.1043    flushSyncCallbackQueue();1044  }1045}1046export function batchedUpdates<A, R>(fn: A => R, a: A): R {1047  const prevExecutionContext = executionContext;1048  executionContext |= BatchedContext;1049  try {1050    return fn(a);1051  } finally {1052    executionContext = prevExecutionContext;1053    if (executionContext === NoContext) {1054      // Flush the immediate callbacks that were scheduled during this batch1055      flushSyncCallbackQueue();1056    }1057  }1058}1059export function batchedEventUpdates<A, R>(fn: A => R, a: A): R {1060  const prevExecutionContext = executionContext;1061  executionContext |= EventContext;1062  try {1063    return fn(a);1064  } finally {1065    executionContext = prevExecutionContext;1066    if (executionContext === NoContext) {1067      // Flush the immediate callbacks that were scheduled during this batch1068      flushSyncCallbackQueue();1069    }1070  }1071}1072export function discreteUpdates<A, B, C, D, R>(1073  fn: (A, B, C) => R,1074  a: A,1075  b: B,1076  c: C,1077  d: D,1078): R {1079  const prevExecutionContext = executionContext;1080  executionContext |= DiscreteEventContext;1081  try {1082    // Should this1083    return runWithPriority(UserBlockingPriority, fn.bind(null, a, b, c, d));1084  } finally {1085    executionContext = prevExecutionContext;1086    if (executionContext === NoContext) {1087      // Flush the immediate callbacks that were scheduled during this batch1088      flushSyncCallbackQueue();1089    }1090  }1091}1092export function unbatchedUpdates<A, R>(fn: (a: A) => R, a: A): R {1093  const prevExecutionContext = executionContext;1094  executionContext &= ~BatchedContext;1095  executionContext |= LegacyUnbatchedContext;1096  try {1097    return fn(a);1098  } finally {1099    executionContext = prevExecutionContext;1100    if (executionContext === NoContext) {1101      // Flush the immediate callbacks that were scheduled during this batch1102      flushSyncCallbackQueue();1103    }1104  }1105}1106export function flushSync<A, R>(fn: A => R, a: A): R {1107  if ((executionContext & (RenderContext | CommitContext)) !== NoContext) {1108    invariant(1109      false,1110      'flushSync was called from inside a lifecycle method. It cannot be ' +1111        'called when React is already rendering.',1112    );1113  }1114  const prevExecutionContext = executionContext;1115  executionContext |= BatchedContext;1116  try {1117    return runWithPriority(ImmediatePriority, fn.bind(null, a));1118  } finally {1119    executionContext = prevExecutionContext;1120    // Flush the immediate callbacks that were scheduled during this batch.1121    // Note that this will happen even if batchedUpdates is higher up1122    // the stack.1123    flushSyncCallbackQueue();1124  }1125}1126export function flushControlled(fn: () => mixed): void {1127  const prevExecutionContext = executionContext;1128  executionContext |= BatchedContext;1129  try {1130    runWithPriority(ImmediatePriority, fn);1131  } finally {1132    executionContext = prevExecutionContext;1133    if (executionContext === NoContext) {1134      // Flush the immediate callbacks that were scheduled during this batch1135      flushSyncCallbackQueue();1136    }1137  }1138}1139function prepareFreshStack(root, expirationTime) {1140  root.finishedWork = null;1141  root.finishedExpirationTime = NoWork;1142  const timeoutHandle = root.timeoutHandle;1143  if (timeoutHandle !== noTimeout) {1144    // The root previous suspended and scheduled a timeout to commit a fallback1145    // state. Now that we have additional work, cancel the timeout.1146    root.timeoutHandle = noTimeout;1147    // $FlowFixMe Complains noTimeout is not a TimeoutID, despite the check above1148    cancelTimeout(timeoutHandle);1149  }1150  if (workInProgress !== null) {1151    let interruptedWork = workInProgress.return;1152    while (interruptedWork !== null) {1153      unwindInterruptedWork(interruptedWork);1154      interruptedWork = interruptedWork.return;1155    }1156  }1157  workInProgressRoot = root;1158  debugger1159  workInProgress = createWorkInProgress(root.current, null);1160  renderExpirationTime = expirationTime;1161  workInProgressRootExitStatus = RootIncomplete;1162  workInProgressRootFatalError = null;1163  workInProgressRootLatestProcessedExpirationTime = Sync;1164  workInProgressRootLatestSuspenseTimeout = Sync;1165  workInProgressRootCanSuspendUsingConfig = null;1166  workInProgressRootNextUnprocessedUpdateTime = NoWork;1167  workInProgressRootHasPendingPing = false;1168  if (enableSchedulerTracing) {1169    spawnedWorkDuringRender = null;1170  }1171  if (true) {1172    ReactStrictModeWarnings.discardPendingWarnings();1173  }1174}1175function handleError(root, thrownValue) {1176  do {1177    try {1178      // Reset module-level state that was set during the render phase.1179      resetContextDependencies();1180      resetHooksAfterThrow();1181      resetCurrentDebugFiberInDEV();1182      if (workInProgress === null || workInProgress.return === null) {1183        // Expected to be working on a non-root fiber. This is a fatal error1184        // because there's no ancestor that can handle it; the root is1185        // supposed to capture all errors that weren't caught by an error1186        // boundary.1187        workInProgressRootExitStatus = RootFatalErrored;1188        workInProgressRootFatalError = thrownValue;1189        // Set `workInProgress` to null. This represents advancing to the next1190        // sibling, or the parent if there are no siblings. But since the root1191        // has no siblings nor a parent, we set it to null. Usually this is1192        // handled by `completeUnitOfWork` or `unwindWork`, but since we're1193        // interntionally not calling those, we need set it here.1194        // TODO: Consider calling `unwindWork` to pop the contexts.1195        workInProgress = null;1196        return null;1197      }1198      if (enableProfilerTimer && workInProgress.mode & ProfileMode) {1199        // Record the time spent rendering before an error was thrown. This1200        // avoids inaccurate Profiler durations in the case of a1201        // suspended render.1202        stopProfilerTimerIfRunningAndRecordDelta(workInProgress, true);1203      }1204      throwException(1205        root,1206        workInProgress.return,1207        workInProgress,1208        thrownValue,1209        renderExpirationTime,1210      );1211      workInProgress = completeUnitOfWork(workInProgress);1212    } catch (yetAnotherThrownValue) {1213      // Something in the return path also threw.1214      thrownValue = yetAnotherThrownValue;1215      continue;1216    }1217    // Return to the normal work loop.1218    return;1219  } while (true);1220}1221function pushDispatcher(root) {1222  const prevDispatcher = ReactCurrentDispatcher.current;1223  ReactCurrentDispatcher.current = ContextOnlyDispatcher;1224  if (prevDispatcher === null) {1225    // The React isomorphic package does not include a default dispatcher.1226    // Instead the first renderer will lazily attach one, in order to give1227    // nicer error messages.1228    return ContextOnlyDispatcher;1229  } else {1230    return prevDispatcher;1231  }1232}1233function popDispatcher(prevDispatcher) {1234  ReactCurrentDispatcher.current = prevDispatcher;1235}1236function pushInteractions(root) {1237  if (enableSchedulerTracing) {1238    const prevInteractions: Set<Interaction> | null = __interactionsRef.current;1239    __interactionsRef.current = root.memoizedInteractions;1240    return prevInteractions;1241  }1242  return null;1243}1244function popInteractions(prevInteractions) {1245  if (enableSchedulerTracing) {1246    __interactionsRef.current = prevInteractions;1247  }1248}1249export function markCommitTimeOfFallback() {1250  globalMostRecentFallbackTime = now();1251}1252export function markRenderEventTimeAndConfig(1253  expirationTime: ExpirationTime,1254  suspenseConfig: null | SuspenseConfig,1255): void {1256  if (1257    expirationTime < workInProgressRootLatestProcessedExpirationTime &&1258    expirationTime > Idle1259  ) {1260    workInProgressRootLatestProcessedExpirationTime = expirationTime;1261  }1262  if (suspenseConfig !== null) {1263    if (1264      expirationTime < workInProgressRootLatestSuspenseTimeout &&1265      expirationTime > Idle1266    ) {1267      workInProgressRootLatestSuspenseTimeout = expirationTime;1268      // Most of the time we only have one config and getting wrong is not bad.1269      workInProgressRootCanSuspendUsingConfig = suspenseConfig;1270    }1271  }1272}1273export function markUnprocessedUpdateTime(1274  expirationTime: ExpirationTime,1275): void {1276  if (expirationTime > workInProgressRootNextUnprocessedUpdateTime) {1277    workInProgressRootNextUnprocessedUpdateTime = expirationTime;1278  }1279}1280export function renderDidSuspend(): void {1281  if (workInProgressRootExitStatus === RootIncomplete) {1282    workInProgressRootExitStatus = RootSuspended;1283  }1284}1285export function renderDidSuspendDelayIfPossible(): void {1286  if (1287    workInProgressRootExitStatus === RootIncomplete ||1288    workInProgressRootExitStatus === RootSuspended1289  ) {1290    workInProgressRootExitStatus = RootSuspendedWithDelay;1291  }1292  // Check if there's a lower priority update somewhere else in the tree.1293  if (1294    workInProgressRootNextUnprocessedUpdateTime !== NoWork &&1295    workInProgressRoot !== null1296  ) {1297    // Mark the current render as suspended, and then mark that there's a1298    // pending update.1299    // TODO: This should immediately interrupt the current render, instead1300    // of waiting until the next time we yield.1301    markRootSuspendedAtTime(workInProgressRoot, renderExpirationTime);1302    markRootUpdatedAtTime(1303      workInProgressRoot,1304      workInProgressRootNextUnprocessedUpdateTime,1305    );1306  }1307}1308export function renderDidError() {1309  if (workInProgressRootExitStatus !== RootCompleted) {1310    workInProgressRootExitStatus = RootErrored;1311  }1312}1313// Called during render to determine if anything has suspended.1314// Returns false if we're not sure.1315export function renderHasNotSuspendedYet(): boolean {1316  // If something errored or completed, we can't really be sure,1317  // so those are false.1318  return workInProgressRootExitStatus === RootIncomplete;1319}1320function inferTimeFromExpirationTime(expirationTime: ExpirationTime): number {1321  // We don't know exactly when the update was scheduled, but we can infer an1322  // approximate start time from the expiration time.1323  const earliestExpirationTimeMs = expirationTimeToMs(expirationTime);1324  return earliestExpirationTimeMs - LOW_PRIORITY_EXPIRATION;1325}1326function inferTimeFromExpirationTimeWithSuspenseConfig(1327  expirationTime: ExpirationTime,1328  suspenseConfig: SuspenseConfig,1329): number {1330  // We don't know exactly when the update was scheduled, but we can infer an1331  // approximate start time from the expiration time by subtracting the timeout1332  // that was added to the event time.1333  const earliestExpirationTimeMs = expirationTimeToMs(expirationTime);1334  return (1335    earliestExpirationTimeMs -1336    (suspenseConfig.timeoutMs | 0 || LOW_PRIORITY_EXPIRATION)1337  );1338}1339// The work loop is an extremely hot path. Tell Closure not to inline it.1340/** @noinline */1341function workLoopSync() {1342  // Already timed out, so perform work without checking if we need to yield.1343  while (workInProgress !== null) {1344    debugger1345    workInProgress = performUnitOfWork(workInProgress);1346  }1347}1348/** @noinline */1349function workLoopConcurrent() {1350  // Perform work until Scheduler asks us to yield1351  while (workInProgress !== null && !shouldYield()) {1352    workInProgress = performUnitOfWork(workInProgress);1353  }1354}1355function performUnitOfWork(unitOfWork: Fiber): Fiber | null {1356  // The current, flushed, state of this fiber is the alternate. Ideally1357  // nothing should rely on this, but relying on it here means that we don't1358  // need an additional field on the work in progress.1359  const current = unitOfWork.alternate;1360  1361  startWorkTimer(unitOfWork);1362  setCurrentDebugFiberInDEV(unitOfWork);1363  let next;1364  if (enableProfilerTimer && (unitOfWork.mode & ProfileMode) !== NoMode) {1365    startProfilerTimer(unitOfWork);1366    debugger;1367    next = beginWork(current, unitOfWork, renderExpirationTime);1368    stopProfilerTimerIfRunningAndRecordDelta(unitOfWork, true);1369  } else {1370    next = beginWork(current, unitOfWork, renderExpirationTime);1371  }1372  resetCurrentDebugFiberInDEV();1373  unitOfWork.memoizedProps = unitOfWork.pendingProps;1374  if (next === null) {1375    // If this doesn't spawn new work, complete the current work.1376    next = completeUnitOfWork(unitOfWork);1377  }1378  console.log(next)1379  ReactCurrentOwner.current = null;1380  return next;1381}1382function completeUnitOfWork(unitOfWork: Fiber): Fiber | null {1383  // Attempt to complete the current unit of work, then move to the next1384  // sibling. If there are no more siblings, return to the parent fiber.1385  workInProgress = unitOfWork;1386  do {1387    // The current, flushed, state of this fiber is the alternate. Ideally1388    // nothing should rely on this, but relying on it here means that we don't1389    // need an additional field on the work in progress.1390    const current = workInProgress.alternate;1391    const returnFiber = workInProgress.return;1392    // Check if the work completed or if something threw.1393    if ((workInProgress.effectTag & Incomplete) === NoEffect) {1394      setCurrentDebugFiberInDEV(workInProgress);1395      let next;1396      if (1397        !enableProfilerTimer ||1398        (workInProgress.mode & ProfileMode) === NoMode1399      ) {1400        next = completeWork(current, workInProgress, renderExpirationTime);1401      } else {1402        startProfilerTimer(workInProgress);1403        next = completeWork(current, workInProgress, renderExpirationTime);1404        // Update render duration assuming we didn't error.1405        stopProfilerTimerIfRunningAndRecordDelta(workInProgress, false);1406      }1407      stopWorkTimer(workInProgress);1408      resetCurrentDebugFiberInDEV();1409      resetChildExpirationTime(workInProgress);1410      if (next !== null) {1411        // Completing this fiber spawned new work. Work on that next.1412        return next;1413      }1414      if (1415        returnFiber !== null &&1416        // Do not append effects to parents if a sibling failed to complete1417        (returnFiber.effectTag & Incomplete) === NoEffect1418      ) {1419        // Append all the effects of the subtree and this fiber onto the effect1420        // list of the parent. The completion order of the children affects the1421        // side-effect order.1422        if (returnFiber.firstEffect === null) {1423          returnFiber.firstEffect = workInProgress.firstEffect;1424        }1425        if (workInProgress.lastEffect !== null) {1426          if (returnFiber.lastEffect !== null) {1427            returnFiber.lastEffect.nextEffect = workInProgress.firstEffect;1428          }1429          returnFiber.lastEffect = workInProgress.lastEffect;1430        }1431        // If this fiber had side-effects, we append it AFTER the children's1432        // side-effects. We can perform certain side-effects earlier if needed,1433        // by doing multiple passes over the effect list. We don't want to1434        // schedule our own side-effect on our own list because if end up1435        // reusing children we'll schedule this effect onto itself since we're1436        // at the end.1437        const effectTag = workInProgress.effectTag;1438        // Skip both NoWork and PerformedWork tags when creating the effect1439        // list. PerformedWork effect is read by React DevTools but shouldn't be1440        // committed.1441        if (effectTag > PerformedWork) {1442          if (returnFiber.lastEffect !== null) {1443            returnFiber.lastEffect.nextEffect = workInProgress;1444          } else {1445            returnFiber.firstEffect = workInProgress;1446          }1447          returnFiber.lastEffect = workInProgress;1448        }1449      }1450    } else {1451      // This fiber did not complete because something threw. Pop values off1452      // the stack without entering the complete phase. If this is a boundary,1453      // capture values if possible.1454      const next = unwindWork(workInProgress, renderExpirationTime);1455      // Because this fiber did not complete, don't reset its expiration time.1456      if (1457        enableProfilerTimer &&1458        (workInProgress.mode & ProfileMode) !== NoMode1459      ) {1460        // Record the render duration for the fiber that errored.1461        stopProfilerTimerIfRunningAndRecordDelta(workInProgress, false);1462        // Include the time spent working on failed children before continuing.1463        let actualDuration = workInProgress.actualDuration;1464        let child = workInProgress.child;1465        while (child !== null) {1466          actualDuration += child.actualDuration;1467          child = child.sibling;1468        }1469        workInProgress.actualDuration = actualDuration;1470      }1471      if (next !== null) {1472        // If completing this work spawned new work, do that next. We'll come1473        // back here again.1474        // Since we're restarting, remove anything that is not a host effect1475        // from the effect tag.1476        // TODO: The name stopFailedWorkTimer is misleading because Suspense1477        // also captures and restarts.1478        stopFailedWorkTimer(workInProgress);1479        next.effectTag &= HostEffectMask;1480        return next;1481      }1482      stopWorkTimer(workInProgress);1483      if (returnFiber !== null) {1484        // Mark the parent fiber as incomplete and clear its effect list.1485        returnFiber.firstEffect = returnFiber.lastEffect = null;1486        returnFiber.effectTag |= Incomplete;1487      }1488    }1489    const siblingFiber = workInProgress.sibling;1490    if (siblingFiber !== null) {1491      // If there is more work to do in this returnFiber, do that next.1492      return siblingFiber;1493    }1494    // Otherwise, return to the parent1495    workInProgress = returnFiber;1496  } while (workInProgress !== null);1497  // We've reached the root.1498  if (workInProgressRootExitStatus === RootIncomplete) {1499    workInProgressRootExitStatus = RootCompleted;1500  }1501  return null;1502}1503function getRemainingExpirationTime(fiber: Fiber) {1504  const updateExpirationTime = fiber.expirationTime;1505  const childExpirationTime = fiber.childExpirationTime;1506  return updateExpirationTime > childExpirationTime1507    ? updateExpirationTime1508    : childExpirationTime;1509}1510function resetChildExpirationTime(completedWork: Fiber) {1511  if (1512    renderExpirationTime !== Never &&1513    completedWork.childExpirationTime === Never1514  ) {1515    // The children of this component are hidden. Don't bubble their1516    // expiration times.1517    return;1518  }1519  let newChildExpirationTime = NoWork;1520  // Bubble up the earliest expiration time.1521  if (enableProfilerTimer && (completedWork.mode & ProfileMode) !== NoMode) {1522    // In profiling mode, resetChildExpirationTime is also used to reset1523    // profiler durations.1524    let actualDuration = completedWork.actualDuration;1525    let treeBaseDuration = completedWork.selfBaseDuration;1526    // When a fiber is cloned, its actualDuration is reset to 0. This value will1527    // only be updated if work is done on the fiber (i.e. it doesn't bailout).1528    // When work is done, it should bubble to the parent's actualDuration. If1529    // the fiber has not been cloned though, (meaning no work was done), then1530    // this value will reflect the amount of time spent working on a previous1531    // render. In that case it should not bubble. We determine whether it was1532    // cloned by comparing the child pointer.1533    const shouldBubbleActualDurations =1534      completedWork.alternate === null ||1535      completedWork.child !== completedWork.alternate.child;1536    let child = completedWork.child;1537    while (child !== null) {1538      const childUpdateExpirationTime = child.expirationTime;1539      const childChildExpirationTime = child.childExpirationTime;1540      if (childUpdateExpirationTime > newChildExpirationTime) {1541        newChildExpirationTime = childUpdateExpirationTime;1542      }1543      if (childChildExpirationTime > newChildExpirationTime) {1544        newChildExpirationTime = childChildExpirationTime;1545      }1546      if (shouldBubbleActualDurations) {1547        actualDuration += child.actualDuration;1548      }1549      treeBaseDuration += child.treeBaseDuration;1550      child = child.sibling;1551    }1552    completedWork.actualDuration = actualDuration;1553    completedWork.treeBaseDuration = treeBaseDuration;1554  } else {1555    let child = completedWork.child;1556    while (child !== null) {1557      const childUpdateExpirationTime = child.expirationTime;1558      const childChildExpirationTime = child.childExpirationTime;1559      if (childUpdateExpirationTime > newChildExpirationTime) {1560        newChildExpirationTime = childUpdateExpirationTime;1561      }1562      if (childChildExpirationTime > newChildExpirationTime) {1563        newChildExpirationTime = childChildExpirationTime;1564      }1565      child = child.sibling;1566    }1567  }1568  completedWork.childExpirationTime = newChildExpirationTime;1569}1570function commitRoot(root) {1571  const renderPriorityLevel = getCurrentPriorityLevel();1572  runWithPriority(1573    ImmediatePriority,1574    commitRootImpl.bind(null, root, renderPriorityLevel),1575  );1576  return null;1577}1578function commitRootImpl(root, renderPriorityLevel) {1579  do {1580    // `flushPassiveEffects` will call `flushSyncUpdateQueue` at the end, which1581    // means `flushPassiveEffects` will sometimes result in additional1582    // passive effects. So we need to keep flushing in a loop until there are1583    // no more pending effects.1584    // TODO: Might be better if `flushPassiveEffects` did not automatically1585    // flush synchronous work at the end, to avoid factoring hazards like this.1586    debugger1587    flushPassiveEffects();1588  } while (rootWithPendingPassiveEffects !== null);1589  flushRenderPhaseStrictModeWarningsInDEV();1590  invariant(1591    (executionContext & (RenderContext | CommitContext)) === NoContext,1592    'Should not already be working.',1593  );1594  const finishedWork = root.finishedWork;1595  const expirationTime = root.finishedExpirationTime;1596  if (finishedWork === null) {1597    return null;1598  }1599  root.finishedWork = null;1600  root.finishedExpirationTime = NoWork;1601  invariant(1602    finishedWork !== root.current,1603    'Cannot commit the same tree as before. This error is likely caused by ' +1604      'a bug in React. Please file an issue.',1605  );1606  // commitRoot never returns a continuation; it always finishes synchronously.1607  // So we can clear these now to allow a new callback to be scheduled.1608  root.callbackNode = null;1609  root.callbackExpirationTime = NoWork;1610  root.callbackPriority = NoPriority;1611  root.nextKnownPendingLevel = NoWork;1612  startCommitTimer();1613  // Update the first and last pending times on this root. The new first1614  // pending time is whatever is left on the root fiber.1615  const remainingExpirationTimeBeforeCommit = getRemainingExpirationTime(1616    finishedWork,1617  );1618  markRootFinishedAtTime(1619    root,1620    expirationTime,1621    remainingExpirationTimeBeforeCommit,1622  );1623  if (root === workInProgressRoot) {1624    // We can reset these now that they are finished.1625    workInProgressRoot = null;1626    workInProgress = null;1627    renderExpirationTime = NoWork;1628  } else {1629    // This indicates that the last root we worked on is not the same one that1630    // we're committing now. This most commonly happens when a suspended root1631    // times out.1632  }1633  // Get the list of effects.1634  let firstEffect;1635  if (finishedWork.effectTag > PerformedWork) {1636    // A fiber's effect list consists only of its children, not itself. So if1637    // the root has an effect, we need to add it to the end of the list. The1638    // resulting list is the set that would belong to the root's parent, if it1639    // had one; that is, all the effects in the tree including the root.1640    if (finishedWork.lastEffect !== null) {1641      finishedWork.lastEffect.nextEffect = finishedWork;1642      firstEffect = finishedWork.firstEffect;1643    } else {1644      firstEffect = finishedWork;1645    }1646  } else {1647    // There is no effect on the root.1648    firstEffect = finishedWork.firstEffect;1649  }1650  if (firstEffect !== null) { // èµ°è¿é1651    const prevExecutionContext = executionContext;1652    executionContext |= CommitContext;1653    const prevInteractions = pushInteractions(root);1654    // Reset this to null before calling lifecycles1655    ReactCurrentOwner.current = null;1656    // The commit phase is broken into several sub-phases. We do a separate pass1657    // of the effect list for each phase: all mutation effects come before all1658    // layout effects, and so on.1659    // The first phase a "before mutation" phase. We use this phase to read the1660    // state of the host tree right before we mutate it. This is where1661    // getSnapshotBeforeUpdate is called.1662    startCommitSnapshotEffectsTimer();1663    prepareForCommit(root.containerInfo);1664    nextEffect = firstEffect;1665    do {1666      if (false) {1667        1668      } else {1669        try {1670          debugger1671          commitBeforeMutationEffects();1672        } catch (error) {1673          invariant(nextEffect !== null, 'Should be working on an effect.');1674          captureCommitPhaseError(nextEffect, error);1675          nextEffect = nextEffect.nextEffect;1676        }1677      }1678    } while (nextEffect !== null);1679    stopCommitSnapshotEffectsTimer();1680    if (enableProfilerTimer) {1681      // Mark the current commit time to be shared by all Profilers in this1682      // batch. This enables them to be grouped later.1683      recordCommitTime();1684    }1685    // The next phase is the mutation phase, where we mutate the host tree.1686    startCommitHostEffectsTimer();1687    nextEffect = firstEffect;1688    do {1689      if (false) {1690        1691      } else {1692        try {1693          debugger1694          commitMutationEffects(root, renderPriorityLevel);1695        } catch (error) {1696          invariant(nextEffect !== null, 'Should be working on an effect.');1697          captureCommitPhaseError(nextEffect, error);1698          nextEffect = nextEffect.nextEffect;1699        }1700      }1701    } while (nextEffect !== null);1702    stopCommitHostEffectsTimer();1703    resetAfterCommit(root.containerInfo);1704    // The work-in-progress tree is now the current tree. This must come after1705    // the mutation phase, so that the previous tree is still current during1706    // componentWillUnmount, but before the layout phase, so that the finished1707    // work is current during componentDidMount/Update.1708    root.current = finishedWork;1709    // The next phase is the layout phase, where we call effects that read1710    // the host tree after it's been mutated. The idiomatic use case for this is1711    // layout, but class component lifecycles also fire here for legacy reasons.1712    startCommitLifeCyclesTimer();1713    nextEffect = firstEffect;1714    do {1715      if (false) {1716        1717      } else {1718        try {1719          debugger1720          commitLayoutEffects(root, expirationTime);1721        } catch (error) {1722          invariant(nextEffect !== null, 'Should be working on an effect.');1723          captureCommitPhaseError(nextEffect, error);1724          nextEffect = nextEffect.nextEffect;1725        }1726      }1727    } while (nextEffect !== null);1728    stopCommitLifeCyclesTimer();1729    nextEffect = null;1730    // Tell Scheduler to yield at the end of the frame, so the browser has an1731    // opportunity to paint.1732    requestPaint();1733    if (enableSchedulerTracing) {1734      popInteractions(((prevInteractions: any): Set<Interaction>));1735    }1736    executionContext = prevExecutionContext;1737  } else {1738    // No effects.1739    root.current = finishedWork;1740    // Measure these anyway so the flamegraph explicitly shows that there were1741    // no effects.1742    // TODO: Maybe there's a better way to report this.1743    startCommitSnapshotEffectsTimer();1744    stopCommitSnapshotEffectsTimer();1745    if (enableProfilerTimer) {1746      recordCommitTime();1747    }1748    startCommitHostEffectsTimer();1749    stopCommitHostEffectsTimer();1750    startCommitLifeCyclesTimer();1751    stopCommitLifeCyclesTimer();1752  }1753  stopCommitTimer();1754  const rootDidHavePassiveEffects = rootDoesHavePassiveEffects;1755  if (rootDoesHavePassiveEffects) {1756    // This commit has passive effects. Stash a reference to them. But don't1757    // schedule a callback until after flushing layout work.1758    rootDoesHavePassiveEffects = false;1759    rootWithPendingPassiveEffects = root;1760    pendingPassiveEffectsExpirationTime = expirationTime;1761    pendingPassiveEffectsRenderPriority = renderPriorityLevel;1762  } else {1763    // We are done with the effect chain at this point so let's clear the1764    // nextEffect pointers to assist with GC. If we have passive effects, we'll1765    // clear this in flushPassiveEffects.1766    nextEffect = firstEffect;1767    while (nextEffect !== null) {1768      const nextNextEffect = nextEffect.nextEffect;1769      nextEffect.nextEffect = null;1770      nextEffect = nextNextEffect;1771    }1772  }1773  // Check if there's remaining work on this root1774  const remainingExpirationTime = root.firstPendingTime;1775  if (remainingExpirationTime !== NoWork) {1776    if (enableSchedulerTracing) {1777      if (spawnedWorkDuringRender !== null) {1778        const expirationTimes = spawnedWorkDuringRender;1779        spawnedWorkDuringRender = null;1780        for (let i = 0; i < expirationTimes.length; i++) {1781          scheduleInteractions(1782            root,1783            expirationTimes[i],1784            root.memoizedInteractions,1785          );1786        }1787      }1788      schedulePendingInteractions(root, remainingExpirationTime);1789    }1790  } else {1791    // If there's no remaining work, we can clear the set of already failed1792    // error boundaries.1793    legacyErrorBoundariesThatAlreadyFailed = null;1794  }1795  if (enableSchedulerTracing) {1796    if (!rootDidHavePassiveEffects) {1797      // If there are no passive effects, then we can complete the pending interactions.1798      // Otherwise, we'll wait until after the passive effects are flushed.1799      // Wait to do this until after remaining work has been scheduled,1800      // so that we don't prematurely signal complete for interactions when there's e.g. hidden work.1801      finishPendingInteractions(root, expirationTime);1802    }1803  }1804  if (remainingExpirationTime === Sync) {1805    // Count the number of times the root synchronously re-renders without1806    // finishing. If there are too many, it indicates an infinite update loop.1807    if (root === rootWithNestedUpdates) {1808      nestedUpdateCount++;1809    } else {1810      nestedUpdateCount = 0;1811      rootWithNestedUpdates = root;1812    }1813  } else {1814    nestedUpdateCount = 0;1815  }1816  onCommitRoot(finishedWork.stateNode, expirationTime);1817  // Always call this before exiting `commitRoot`, to ensure that any1818  // additional work on this root is scheduled.1819  ensureRootIsScheduled(root);1820  if (hasUncaughtError) {1821    hasUncaughtError = false;1822    const error = firstUncaughtError;1823    firstUncaughtError = null;1824    throw error;1825  }1826  if ((executionContext & LegacyUnbatchedContext) !== NoContext) {1827    // This is a legacy edge case. We just committed the initial mount of1828    // a ReactDOM.render-ed root inside of batchedUpdates. The commit fired1829    // synchronously, but layout updates should be deferred until the end1830    // of the batch.1831    return null;1832  }1833  // If layout work was scheduled, flush it now.1834  flushSyncCallbackQueue();1835  return null;1836}1837function commitBeforeMutationEffects() {1838  while (nextEffect !== null) {1839    const effectTag = nextEffect.effectTag;1840    if ((effectTag & Snapshot) !== NoEffect) {1841      setCurrentDebugFiberInDEV(nextEffect);1842      recordEffect();1843      const current = nextEffect.alternate;1844      commitBeforeMutationEffectOnFiber(current, nextEffect);1845      resetCurrentDebugFiberInDEV();1846    }1847    if ((effectTag & Passive) !== NoEffect) {1848      // If there are passive effects, schedule a callback to flush at1849      // the earliest opportunity.1850      if (!rootDoesHavePassiveEffects) {1851        rootDoesHavePassiveEffects = true;1852        scheduleCallback(NormalPriority, () => {1853          flushPassiveEffects();1854          return null;1855        });1856      }1857    }1858    nextEffect = nextEffect.nextEffect;1859  }1860}1861function commitMutationEffects(root: FiberRoot, renderPriorityLevel) {1862  // TODO: Should probably move the bulk of this function to commitWork.1863  while (nextEffect !== null) {1864    setCurrentDebugFiberInDEV(nextEffect);1865    const effectTag = nextEffect.effectTag;1866    if (effectTag & ContentReset) {1867      commitResetTextContent(nextEffect);1868    }1869    if (effectTag & Ref) {1870      const current = nextEffect.alternate;1871      if (current !== null) {1872        commitDetachRef(current);1873      }1874    }1875    // The following switch statement is only concerned about placement,1876    // updates, and deletions. To avoid needing to add a case for every possible1877    // bitmap value, we remove the secondary effects from the effect tag and1878    // switch on that value.1879    let primaryEffectTag =1880      effectTag & (Placement | Update | Deletion | Hydrating);1881    switch (primaryEffectTag) {1882      case Placement: {1883        commitPlacement(nextEffect);1884        // Clear the "placement" from effect tag so that we know that this is1885        // inserted, before any life-cycles like componentDidMount gets called.1886        // TODO: findDOMNode doesn't rely on this any more but isMounted does1887        // and isMounted is deprecated anyway so we should be able to kill this.1888        nextEffect.effectTag &= ~Placement;1889        break;1890      }1891      case PlacementAndUpdate: {1892        // Placement1893        commitPlacement(nextEffect);1894        // Clear the "placement" from effect tag so that we know that this is1895        // inserted, before any life-cycles like componentDidMount gets called.1896        nextEffect.effectTag &= ~Placement;1897        // Update1898        const current = nextEffect.alternate;1899        commitWork(current, nextEffect);1900        break;1901      }1902      case Hydrating: {1903        nextEffect.effectTag &= ~Hydrating;1904        break;1905      }1906      case HydratingAndUpdate: {1907        nextEffect.effectTag &= ~Hydrating;1908        // Update1909        const current = nextEffect.alternate;1910        commitWork(current, nextEffect);1911        break;1912      }1913      case Update: {1914        const current = nextEffect.alternate;1915        commitWork(current, nextEffect);1916        break;1917      }1918      case Deletion: {1919        commitDeletion(root, nextEffect, renderPriorityLevel);1920        break;1921      }1922    }1923    // TODO: Only record a mutation effect if primaryEffectTag is non-zero.1924    recordEffect();1925    resetCurrentDebugFiberInDEV();1926    nextEffect = nextEffect.nextEffect;1927  }1928}1929function commitLayoutEffects(1930  root: FiberRoot,1931  committedExpirationTime: ExpirationTime,1932) {1933  // TODO: Should probably move the bulk of this function to commitWork.1934  while (nextEffect !== null) {1935    setCurrentDebugFiberInDEV(nextEffect);1936    const effectTag = nextEffect.effectTag;1937    if (effectTag & (Update | Callback)) {1938      recordEffect();1939      const current = nextEffect.alternate;1940      commitLayoutEffectOnFiber(1941        root,1942        current,1943        nextEffect,1944        committedExpirationTime,1945      );1946    }1947    if (effectTag & Ref) {1948      recordEffect();1949      commitAttachRef(nextEffect);1950    }1951    resetCurrentDebugFiberInDEV();1952    nextEffect = nextEffect.nextEffect;1953  }1954}1955export function flushPassiveEffects() {1956  if (pendingPassiveEffectsRenderPriority !== NoPriority) {1957    const priorityLevel =1958      pendingPassiveEffectsRenderPriority > NormalPriority1959        ? NormalPriority1960        : pendingPassiveEffectsRenderPriority;1961    pendingPassiveEffectsRenderPriority = NoPriority;1962    return runWithPriority(priorityLevel, flushPassiveEffectsImpl);1963  }1964}1965export function enqueuePendingPassiveHookEffectMount(1966  fiber: Fiber,1967  effect: HookEffect,1968): void {1969  if (runAllPassiveEffectDestroysBeforeCreates) {1970    pendingPassiveHookEffectsMount.push(effect, fiber);1971    if (!rootDoesHavePassiveEffects) {1972      rootDoesHavePassiveEffects = true;1973      scheduleCallback(NormalPriority, () => {1974        flushPassiveEffects();1975        return null;1976      });1977    }1978  }1979}1980export function enqueuePendingPassiveHookEffectUnmount(1981  fiber: Fiber,1982  effect: HookEffect,1983): void {1984  if (runAllPassiveEffectDestroysBeforeCreates) {1985    pendingPassiveHookEffectsUnmount.push(effect, fiber);1986    if (!rootDoesHavePassiveEffects) {1987      rootDoesHavePassiveEffects = true;1988      scheduleCallback(NormalPriority, () => {1989        flushPassiveEffects();1990        return null;1991      });1992    }1993  }1994}1995function invokePassiveEffectCreate(effect: HookEffect): void {1996  const create = effect.create;1997  effect.destroy = create();1998}1999function flushPassiveEffectsImpl() {2000  if (rootWithPendingPassiveEffects === null) {2001    return false;2002  }2003  const root = rootWithPendingPassiveEffects;2004  const expirationTime = pendingPassiveEffectsExpirationTime;2005  rootWithPendingPassiveEffects = null;2006  pendingPassiveEffectsExpirationTime = NoWork;2007  invariant(2008    (executionContext & (RenderContext | CommitContext)) === NoContext,2009    'Cannot flush passive effects while already rendering.',2010  );2011  const prevExecutionContext = executionContext;2012  executionContext |= CommitContext;2013  const prevInteractions = pushInteractions(root);2014  if (runAllPassiveEffectDestroysBeforeCreates) {2015    // It's important that ALL pending passive effect destroy functions are called2016    // before ANY passive effect create functions are called.2017    // Otherwise effects in sibling components might interfere with each other.2018    // e.g. a destroy function in one component may unintentionally override a ref2019    // value set by a create function in another component.2020    // Layout effects have the same constraint.2021    // First pass: Destroy stale passive effects.2022    let unmountEffects = pendingPassiveHookEffectsUnmount;2023    pendingPassiveHookEffectsUnmount = [];2024    for (let i = 0; i < unmountEffects.length; i += 2) {2025      const effect = ((unmountEffects[i]: any): HookEffect);2026      const fiber = ((unmountEffects[i + 1]: any): Fiber);2027      const destroy = effect.destroy;2028      effect.destroy = undefined;2029      if (typeof destroy === 'function') {2030        if (true) {2031          setCurrentDebugFiberInDEV(fiber);2032          invokeGuardedCallback(null, destroy, null);2033          if (hasCaughtError()) {2034            invariant(fiber !== null, 'Should be working on an effect.');2035            const error = clearCaughtError();2036            captureCommitPhaseError(fiber, error);2037          }2038          resetCurrentDebugFiberInDEV();2039        } else {2040          try {2041            destroy();2042          } catch (error) {2043            invariant(fiber !== null, 'Should be working on an effect.');2044            captureCommitPhaseError(fiber, error);2045          }2046        }2047      }2048    }2049    // Second pass: Create new passive effects.2050    let mountEffects = pendingPassiveHookEffectsMount;2051    pendingPassiveHookEffectsMount = [];2052    for (let i = 0; i < mountEffects.length; i += 2) {2053      const effect = ((mountEffects[i]: any): HookEffect);2054      const fiber = ((mountEffects[i + 1]: any): Fiber);2055      if (true) {2056        setCurrentDebugFiberInDEV(fiber);2057        invokeGuardedCallback(null, invokePassiveEffectCreate, null, effect);2058        if (hasCaughtError()) {2059          invariant(fiber !== null, 'Should be working on an effect.');2060          const error = clearCaughtError();2061          captureCommitPhaseError(fiber, error);2062        }2063        resetCurrentDebugFiberInDEV();2064      } else {2065        try {2066          const create = effect.create;2067          effect.destroy = create();2068        } catch (error) {2069          invariant(fiber !== null, 'Should be working on an effect.');2070          captureCommitPhaseError(fiber, error);2071        }2072      }2073    }2074  } else {2075    // Note: This currently assumes there are no passive effects on the root fiber2076    // because the root is not part of its own effect list.2077    // This could change in the future.2078    let effect = root.current.firstEffect;2079    while (effect !== null) {2080      if (true) {2081        setCurrentDebugFiberInDEV(effect);2082        invokeGuardedCallback(null, commitPassiveHookEffects, null, effect);2083        if (hasCaughtError()) {2084          invariant(effect !== null, 'Should be working on an effect.');2085          const error = clearCaughtError();2086          captureCommitPhaseError(effect, error);2087        }2088        resetCurrentDebugFiberInDEV();2089      } else {2090        try {2091          commitPassiveHookEffects(effect);2092        } catch (error) {2093          invariant(effect !== null, 'Should be working on an effect.');2094          captureCommitPhaseError(effect, error);2095        }2096      }2097      const nextNextEffect = effect.nextEffect;2098      // Remove nextEffect pointer to assist GC2099      effect.nextEffect = null;2100      effect = nextNextEffect;2101    }2102  }2103  if (enableSchedulerTracing) {2104    popInteractions(((prevInteractions: any): Set<Interaction>));2105    finishPendingInteractions(root, expirationTime);2106  }2107  executionContext = prevExecutionContext;2108  flushSyncCallbackQueue();2109  // If additional passive effects were scheduled, increment a counter. If this2110  // exceeds the limit, we'll fire a warning.2111  nestedPassiveUpdateCount =2112    rootWithPendingPassiveEffects === null ? 0 : nestedPassiveUpdateCount + 1;2113  return true;2114}2115export function isAlreadyFailedLegacyErrorBoundary(instance: mixed): boolean {2116  return (2117    legacyErrorBoundariesThatAlreadyFailed !== null &&2118    legacyErrorBoundariesThatAlreadyFailed.has(instance)2119  );2120}2121export function markLegacyErrorBoundaryAsFailed(instance: mixed) {2122  if (legacyErrorBoundariesThatAlreadyFailed === null) {2123    legacyErrorBoundariesThatAlreadyFailed = new Set([instance]);2124  } else {2125    legacyErrorBoundariesThatAlreadyFailed.add(instance);2126  }2127}2128function prepareToThrowUncaughtError(error: mixed) {2129  if (!hasUncaughtError) {2130    hasUncaughtError = true;2131    firstUncaughtError = error;2132  }2133}2134export const onUncaughtError = prepareToThrowUncaughtError;2135function captureCommitPhaseErrorOnRoot(2136  rootFiber: Fiber,2137  sourceFiber: Fiber,2138  error: mixed,2139) {2140  const errorInfo = createCapturedValue(error, sourceFiber);2141  const update = createRootErrorUpdate(rootFiber, errorInfo, Sync);2142  enqueueUpdate(rootFiber, update);2143  const root = markUpdateTimeFromFiberToRoot(rootFiber, Sync);2144  if (root !== null) {2145    ensureRootIsScheduled(root);2146    schedulePendingInteractions(root, Sync);2147  }2148}2149export function captureCommitPhaseError(sourceFiber: Fiber, error: mixed) {2150  if (sourceFiber.tag === HostRoot) {2151    // Error was thrown at the root. There is no parent, so the root2152    // itself should capture it.2153    captureCommitPhaseErrorOnRoot(sourceFiber, sourceFiber, error);2154    return;2155  }2156  let fiber = sourceFiber.return;2157  while (fiber !== null) {2158    if (fiber.tag === HostRoot) {2159      captureCommitPhaseErrorOnRoot(fiber, sourceFiber, error);2160      return;2161    } else if (fiber.tag === ClassComponent) {2162      const ctor = fiber.type;2163      const instance = fiber.stateNode;2164      if (2165        typeof ctor.getDerivedStateFromError === 'function' ||2166        (typeof instance.componentDidCatch === 'function' &&2167          !isAlreadyFailedLegacyErrorBoundary(instance))2168      ) {2169        const errorInfo = createCapturedValue(error, sourceFiber);2170        const update = createClassErrorUpdate(2171          fiber,2172          errorInfo,2173          // TODO: This is always sync2174          Sync,2175        );2176        enqueueUpdate(fiber, update);2177        const root = markUpdateTimeFromFiberToRoot(fiber, Sync);2178        if (root !== null) {2179          ensureRootIsScheduled(root);2180          schedulePendingInteractions(root, Sync);2181        }2182        return;2183      }2184    }2185    fiber = fiber.return;2186  }2187}2188export function pingSuspendedRoot(2189  root: FiberRoot,2190  thenable: Thenable,2191  suspendedTime: ExpirationTime,2192) {2193  const pingCache = root.pingCache;2194  if (pingCache !== null) {2195    // The thenable resolved, so we no longer need to memoize, because it will2196    // never be thrown again.2197    pingCache.delete(thenable);2198  }2199  if (workInProgressRoot === root && renderExpirationTime === suspendedTime) {2200    // Received a ping at the same priority level at which we're currently2201    // rendering. We might want to restart this render. This should mirror2202    // the logic of whether or not a root suspends once it completes.2203    // TODO: If we're rendering sync either due to Sync, Batched or expired,2204    // we should probably never restart.2205    // If we're suspended with delay, we'll always suspend so we can always2206    // restart. If we're suspended without any updates, it might be a retry.2207    // If it's early in the retry we can restart. We can't know for sure2208    // whether we'll eventually process an update during this render pass,2209    // but it's somewhat unlikely that we get to a ping before that, since2210    // getting to the root most update is usually very fast.2211    if (2212      workInProgressRootExitStatus === RootSuspendedWithDelay ||2213      (workInProgressRootExitStatus === RootSuspended &&2214        workInProgressRootLatestProcessedExpirationTime === Sync &&2215        now() - globalMostRecentFallbackTime < FALLBACK_THROTTLE_MS)2216    ) {2217      // Restart from the root. Don't need to schedule a ping because2218      // we're already working on this tree.2219      prepareFreshStack(root, renderExpirationTime);2220    } else {2221      // Even though we can't restart right now, we might get an2222      // opportunity later. So we mark this render as having a ping.2223      workInProgressRootHasPendingPing = true;2224    }2225    return;2226  }2227  if (!isRootSuspendedAtTime(root, suspendedTime)) {2228    // The root is no longer suspended at this time.2229    return;2230  }2231  const lastPingedTime = root.lastPingedTime;2232  if (lastPingedTime !== NoWork && lastPingedTime < suspendedTime) {2233    // There's already a lower priority ping scheduled.2234    return;2235  }2236  // Mark the time at which this ping was scheduled.2237  root.lastPingedTime = suspendedTime;2238  if (!enableTrainModelFix && root.finishedExpirationTime === suspendedTime) {2239    // If there's a pending fallback waiting to commit, throw it away.2240    root.finishedExpirationTime = NoWork;2241    root.finishedWork = null;2242  }2243  ensureRootIsScheduled(root);2244  schedulePendingInteractions(root, suspendedTime);2245}2246function retryTimedOutBoundary(2247  boundaryFiber: Fiber,2248  retryTime: ExpirationTime,2249) {2250  // The boundary fiber (a Suspense component or SuspenseList component)2251  // previously was rendered in its fallback state. One of the promises that2252  // suspended it has resolved, which means at least part of the tree was2253  // likely unblocked. Try rendering again, at a new expiration time.2254  if (retryTime === NoWork) {2255    const suspenseConfig = null; // Retries don't carry over the already committed update.2256    const currentTime = requestCurrentTimeForUpdate();2257    retryTime = computeExpirationForFiber(2258      currentTime,2259      boundaryFiber,2260      suspenseConfig,2261    );2262  }2263  // TODO: Special case idle priority?2264  const root = markUpdateTimeFromFiberToRoot(boundaryFiber, retryTime);2265  if (root !== null) {2266    ensureRootIsScheduled(root);2267    schedulePendingInteractions(root, retryTime);2268  }2269}2270export function retryDehydratedSuspenseBoundary(boundaryFiber: Fiber) {2271  const suspenseState: null | SuspenseState = boundaryFiber.memoizedState;2272  let retryTime = NoWork;2273  if (suspenseState !== null) {2274    retryTime = suspenseState.retryTime;2275  }2276  retryTimedOutBoundary(boundaryFiber, retryTime);2277}2278export function resolveRetryThenable(boundaryFiber: Fiber, thenable: Thenable) {2279  let retryTime = NoWork; // Default2280  let retryCache: WeakSet<Thenable> | Set<Thenable> | null;2281  if (enableSuspenseServerRenderer) {2282    switch (boundaryFiber.tag) {2283      case SuspenseComponent:2284        retryCache = boundaryFiber.stateNode;2285        const suspenseState: null | SuspenseState = boundaryFiber.memoizedState;2286        if (suspenseState !== null) {2287          retryTime = suspenseState.retryTime;2288        }2289        break;2290      case SuspenseListComponent:2291        retryCache = boundaryFiber.stateNode;2292        break;2293      default:2294        invariant(2295          false,2296          'Pinged unknown suspense boundary type. ' +2297            'This is probably a bug in React.',2298        );2299    }2300  } else {2301    retryCache = boundaryFiber.stateNode;2302  }2303  if (retryCache !== null) {2304    // The thenable resolved, so we no longer need to memoize, because it will2305    // never be thrown again.2306    retryCache.delete(thenable);2307  }2308  retryTimedOutBoundary(boundaryFiber, retryTime);2309}2310// Computes the next Just Noticeable Difference (JND) boundary.2311// The theory is that a person can't tell the difference between small differences in time.2312// Therefore, if we wait a bit longer than necessary that won't translate to a noticeable2313// difference in the experience. However, waiting for longer might mean that we can avoid2314// showing an intermediate loading state. The longer we have already waited, the harder it2315// is to tell small differences in time. Therefore, the longer we've already waited,2316// the longer we can wait additionally. At some point we have to give up though.2317// We pick a train model where the next boundary commits at a consistent schedule.2318// These particular numbers are vague estimates. We expect to adjust them based on research.2319function jnd(timeElapsed: number) {2320  return timeElapsed < 1202321    ? 1202322    : timeElapsed < 4802323    ? 4802324    : timeElapsed < 10802325    ? 10802326    : timeElapsed < 19202327    ? 19202328    : timeElapsed < 30002329    ? 30002330    : timeElapsed < 43202331    ? 43202332    : ceil(timeElapsed / 1960) * 1960;2333}2334function computeMsUntilSuspenseLoadingDelay(2335  mostRecentEventTime: ExpirationTime,2336  committedExpirationTime: ExpirationTime,2337  suspenseConfig: SuspenseConfig,2338) {2339  const busyMinDurationMs = (suspenseConfig.busyMinDurationMs: any) | 0;2340  if (busyMinDurationMs <= 0) {2341    return 0;2342  }2343  const busyDelayMs = (suspenseConfig.busyDelayMs: any) | 0;2344  // Compute the time until this render pass would expire.2345  const currentTimeMs: number = now();2346  const eventTimeMs: number = inferTimeFromExpirationTimeWithSuspenseConfig(2347    mostRecentEventTime,2348    suspenseConfig,2349  );2350  const timeElapsed = currentTimeMs - eventTimeMs;2351  if (timeElapsed <= busyDelayMs) {2352    // If we haven't yet waited longer than the initial delay, we don't2353    // have to wait any additional time.2354    return 0;2355  }2356  const msUntilTimeout = busyDelayMs + busyMinDurationMs - timeElapsed;2357  // This is the value that is passed to `setTimeout`.2358  return msUntilTimeout;2359}2360function checkForNestedUpdates() {2361  if (nestedUpdateCount > NESTED_UPDATE_LIMIT) {2362    nestedUpdateCount = 0;2363    rootWithNestedUpdates = null;2364    invariant(2365      false,2366      'Maximum update depth exceeded. This can happen when a component ' +2367        'repeatedly calls setState inside componentWillUpdate or ' +2368        'componentDidUpdate. React limits the number of nested updates to ' +2369        'prevent infinite loops.',2370    );2371  }2372}2373function flushRenderPhaseStrictModeWarningsInDEV() {2374  if (true) {2375    ReactStrictModeWarnings.flushLegacyContextWarning();2376    if (warnAboutDeprecatedLifecycles) {2377      ReactStrictModeWarnings.flushPendingUnsafeLifecycleWarnings();2378    }2379  }2380}2381function stopFinishedWorkLoopTimer() {2382  const didCompleteRoot = true;2383  stopWorkLoopTimer(interruptedBy, didCompleteRoot);2384  interruptedBy = null;2385}2386function stopInterruptedWorkLoopTimer() {2387  // TODO: Track which fiber caused the interruption.2388  const didCompleteRoot = false;2389  stopWorkLoopTimer(interruptedBy, didCompleteRoot);2390  interruptedBy = null;2391}2392function checkForInterruption(2393  fiberThatReceivedUpdate: Fiber,2394  updateExpirationTime: ExpirationTime,2395) {...ReactFiberScheduler.new.js
Source:ReactFiberScheduler.new.js  
...760    }761  }762  // We now have a consistent tree. The next step is either to commit it, or, if763  // something suspended, wait to commit it after a timeout.764  stopFinishedWorkLoopTimer();765  const isLocked = resolveLocksOnRoot(root, expirationTime);766  if (isLocked) {767    // This root has a lock that prevents it from committing. Exit. If we begin768    // work on the root again, without any intervening updates, it will finish769    // without doing additional work.770    return null;771  }772  // Set this to null to indicate there's no in-progress render.773  workInProgressRoot = null;774  switch (workInProgressRootExitStatus) {775    case RootIncomplete: {776      invariant(false, 'Should have a work-in-progress.');777    }778    // Flow knows about invariant, so it compains if I add a break statement,779    // but eslint doesn't know about invariant, so it complains if I do.780    // eslint-disable-next-line no-fallthrough781    case RootErrored: {782      // An error was thrown. First check if there is lower priority work783      // scheduled on this root.784      const lastPendingTime = root.lastPendingTime;785      if (root.lastPendingTime < expirationTime) {786        // There's lower priority work. Before raising the error, try rendering787        // at the lower priority to see if it fixes it. Use a continuation to788        // maintain the existing priority and position in the queue.789        return renderRoot.bind(null, root, lastPendingTime);790      }791      if (!isSync) {792        // If we're rendering asynchronously, it's possible the error was793        // caused by tearing due to a mutation during an event. Try rendering794        // one more time without yiedling to events.795        prepareFreshStack(root, expirationTime);796        scheduleCallback(797          ImmediatePriority,798          renderRoot.bind(null, root, expirationTime),799        );800        return null;801      }802      // If we're already rendering synchronously, commit the root in its803      // errored state.804      return commitRoot.bind(null, root, expirationTime);805    }806    case RootSuspended: {807      const lastPendingTime = root.lastPendingTime;808      if (root.lastPendingTime < expirationTime) {809        // There's lower priority work. It might be unsuspended. Try rendering810        // at that level.811        return renderRoot.bind(null, root, lastPendingTime);812      }813      if (!isSync) {814        const msUntilTimeout = computeMsUntilTimeout(815          root,816          workInProgressRootAbsoluteTimeoutMs,817        );818        if (msUntilTimeout > 0) {819          // The render is suspended, it hasn't timed out, and there's no lower820          // priority work to do. Instead of committing the fallback821          // immediately, wait for more data to arrive.822          root.timeoutHandle = scheduleTimeout(823            commitRoot.bind(null, root, expirationTime),824            msUntilTimeout,825          );826          return null;827        }828      }829      // The work expired. Commit immediately.830      return commitRoot.bind(null, root, expirationTime);831    }832    case RootCompleted: {833      // The work completed. Ready to commit.834      return commitRoot.bind(null, root, expirationTime);835    }836    default: {837      invariant(false, 'Unknown root exit status.');838    }839  }840}841export function renderDidSuspend(842  root: FiberRoot,843  absoluteTimeoutMs: number,844  // TODO: Don't need this argument anymore845  suspendedTime: ExpirationTime,846) {847  if (848    absoluteTimeoutMs >= 0 &&849    workInProgressRootAbsoluteTimeoutMs < absoluteTimeoutMs850  ) {851    workInProgressRootAbsoluteTimeoutMs = absoluteTimeoutMs;852    if (workInProgressRootExitStatus === RootIncomplete) {853      workInProgressRootExitStatus = RootSuspended;854    }855  }856}857export function renderDidError() {858  if (859    workInProgressRootExitStatus === RootIncomplete ||860    workInProgressRootExitStatus === RootSuspended861  ) {862    workInProgressRootExitStatus = RootErrored;863  }864}865function workLoopSync() {866  // Already timed out, so perform work without checking if we need to yield.867  while (workInProgress !== null) {868    workInProgress = performUnitOfWork(workInProgress);869  }870}871function workLoop() {872  // Perform work until Scheduler asks us to yield873  while (workInProgress !== null && !shouldYield()) {874    workInProgress = performUnitOfWork(workInProgress);875  }876}877function performUnitOfWork(unitOfWork: Fiber): Fiber | null {878  // The current, flushed, state of this fiber is the alternate. Ideally879  // nothing should rely on this, but relying on it here means that we don't880  // need an additional field on the work in progress.881  const current = unitOfWork.alternate;882  startWorkTimer(unitOfWork);883  setCurrentDebugFiberInDEV(unitOfWork);884  let next;885  if (enableProfilerTimer && (unitOfWork.mode & ProfileMode) !== NoContext) {886    startProfilerTimer(unitOfWork);887    next = beginWork(current, unitOfWork, renderExpirationTime);888    stopProfilerTimerIfRunningAndRecordDelta(unitOfWork, true);889  } else {890    next = beginWork(current, unitOfWork, renderExpirationTime);891  }892  resetCurrentDebugFiberInDEV();893  unitOfWork.memoizedProps = unitOfWork.pendingProps;894  if (next === null) {895    // If this doesn't spawn new work, complete the current work.896    next = completeUnitOfWork(unitOfWork);897  }898  ReactCurrentOwner.current = null;899  return next;900}901function completeUnitOfWork(unitOfWork: Fiber): Fiber | null {902  // Attempt to complete the current unit of work, then move to the next903  // sibling. If there are no more siblings, return to the parent fiber.904  workInProgress = unitOfWork;905  do {906    // The current, flushed, state of this fiber is the alternate. Ideally907    // nothing should rely on this, but relying on it here means that we don't908    // need an additional field on the work in progress.909    const current = workInProgress.alternate;910    const returnFiber = workInProgress.return;911    // Check if the work completed or if something threw.912    if ((workInProgress.effectTag & Incomplete) === NoEffect) {913      setCurrentDebugFiberInDEV(workInProgress);914      let next;915      if (916        !enableProfilerTimer ||917        (workInProgress.mode & ProfileMode) === NoContext918      ) {919        next = completeWork(current, workInProgress, renderExpirationTime);920      } else {921        startProfilerTimer(workInProgress);922        next = completeWork(current, workInProgress, renderExpirationTime);923        // Update render duration assuming we didn't error.924        stopProfilerTimerIfRunningAndRecordDelta(workInProgress, false);925      }926      stopWorkTimer(workInProgress);927      resetCurrentDebugFiberInDEV();928      resetChildExpirationTime(workInProgress);929      if (next !== null) {930        // Completing this fiber spawned new work. Work on that next.931        return next;932      }933      if (934        returnFiber !== null &&935        // Do not append effects to parents if a sibling failed to complete936        (returnFiber.effectTag & Incomplete) === NoEffect937      ) {938        // Append all the effects of the subtree and this fiber onto the effect939        // list of the parent. The completion order of the children affects the940        // side-effect order.941        if (returnFiber.firstEffect === null) {942          returnFiber.firstEffect = workInProgress.firstEffect;943        }944        if (workInProgress.lastEffect !== null) {945          if (returnFiber.lastEffect !== null) {946            returnFiber.lastEffect.nextEffect = workInProgress.firstEffect;947          }948          returnFiber.lastEffect = workInProgress.lastEffect;949        }950        // If this fiber had side-effects, we append it AFTER the children's951        // side-effects. We can perform certain side-effects earlier if needed,952        // by doing multiple passes over the effect list. We don't want to953        // schedule our own side-effect on our own list because if end up954        // reusing children we'll schedule this effect onto itself since we're955        // at the end.956        const effectTag = workInProgress.effectTag;957        // Skip both NoWork and PerformedWork tags when creating the effect958        // list. PerformedWork effect is read by React DevTools but shouldn't be959        // committed.960        if (effectTag > PerformedWork) {961          if (returnFiber.lastEffect !== null) {962            returnFiber.lastEffect.nextEffect = workInProgress;963          } else {964            returnFiber.firstEffect = workInProgress;965          }966          returnFiber.lastEffect = workInProgress;967        }968      }969    } else {970      // This fiber did not complete because something threw. Pop values off971      // the stack without entering the complete phase. If this is a boundary,972      // capture values if possible.973      const next = unwindWork(workInProgress, renderExpirationTime);974      // Because this fiber did not complete, don't reset its expiration time.975      if (976        enableProfilerTimer &&977        (workInProgress.mode & ProfileMode) !== NoContext978      ) {979        // Record the render duration for the fiber that errored.980        stopProfilerTimerIfRunningAndRecordDelta(workInProgress, false);981        // Include the time spent working on failed children before continuing.982        let actualDuration = workInProgress.actualDuration;983        let child = workInProgress.child;984        while (child !== null) {985          actualDuration += child.actualDuration;986          child = child.sibling;987        }988        workInProgress.actualDuration = actualDuration;989      }990      if (next !== null) {991        // If completing this work spawned new work, do that next. We'll come992        // back here again.993        // Since we're restarting, remove anything that is not a host effect994        // from the effect tag.995        // TODO: The name stopFailedWorkTimer is misleading because Suspense996        // also captures and restarts.997        stopFailedWorkTimer(workInProgress);998        next.effectTag &= HostEffectMask;999        return next;1000      }1001      stopWorkTimer(workInProgress);1002      if (returnFiber !== null) {1003        // Mark the parent fiber as incomplete and clear its effect list.1004        returnFiber.firstEffect = returnFiber.lastEffect = null;1005        returnFiber.effectTag |= Incomplete;1006      }1007    }1008    const siblingFiber = workInProgress.sibling;1009    if (siblingFiber !== null) {1010      // If there is more work to do in this returnFiber, do that next.1011      return siblingFiber;1012    }1013    // Otherwise, return to the parent1014    workInProgress = returnFiber;1015  } while (workInProgress !== null);1016  // We've reached the root.1017  if (workInProgressRootExitStatus === RootIncomplete) {1018    workInProgressRootExitStatus = RootCompleted;1019  }1020  return null;1021}1022function resetChildExpirationTime(completedWork: Fiber) {1023  if (1024    renderExpirationTime !== Never &&1025    completedWork.childExpirationTime === Never1026  ) {1027    // The children of this component are hidden. Don't bubble their1028    // expiration times.1029    return;1030  }1031  let newChildExpirationTime = NoWork;1032  // Bubble up the earliest expiration time.1033  if (enableProfilerTimer && (completedWork.mode & ProfileMode) !== NoContext) {1034    // In profiling mode, resetChildExpirationTime is also used to reset1035    // profiler durations.1036    let actualDuration = completedWork.actualDuration;1037    let treeBaseDuration = completedWork.selfBaseDuration;1038    // When a fiber is cloned, its actualDuration is reset to 0. This value will1039    // only be updated if work is done on the fiber (i.e. it doesn't bailout).1040    // When work is done, it should bubble to the parent's actualDuration. If1041    // the fiber has not been cloned though, (meaning no work was done), then1042    // this value will reflect the amount of time spent working on a previous1043    // render. In that case it should not bubble. We determine whether it was1044    // cloned by comparing the child pointer.1045    const shouldBubbleActualDurations =1046      completedWork.alternate === null ||1047      completedWork.child !== completedWork.alternate.child;1048    let child = completedWork.child;1049    while (child !== null) {1050      const childUpdateExpirationTime = child.expirationTime;1051      const childChildExpirationTime = child.childExpirationTime;1052      if (childUpdateExpirationTime > newChildExpirationTime) {1053        newChildExpirationTime = childUpdateExpirationTime;1054      }1055      if (childChildExpirationTime > newChildExpirationTime) {1056        newChildExpirationTime = childChildExpirationTime;1057      }1058      if (shouldBubbleActualDurations) {1059        actualDuration += child.actualDuration;1060      }1061      treeBaseDuration += child.treeBaseDuration;1062      child = child.sibling;1063    }1064    completedWork.actualDuration = actualDuration;1065    completedWork.treeBaseDuration = treeBaseDuration;1066  } else {1067    let child = completedWork.child;1068    while (child !== null) {1069      const childUpdateExpirationTime = child.expirationTime;1070      const childChildExpirationTime = child.childExpirationTime;1071      if (childUpdateExpirationTime > newChildExpirationTime) {1072        newChildExpirationTime = childUpdateExpirationTime;1073      }1074      if (childChildExpirationTime > newChildExpirationTime) {1075        newChildExpirationTime = childChildExpirationTime;1076      }1077      child = child.sibling;1078    }1079  }1080  completedWork.childExpirationTime = newChildExpirationTime;1081}1082function commitRoot(root, expirationTime) {1083  runWithPriority(1084    ImmediatePriority,1085    commitRootImpl.bind(null, root, expirationTime),1086  );1087  // If there are passive effects, schedule a callback to flush them. This goes1088  // outside commitRootImpl so that it inherits the priority of the render.1089  if (rootWithPendingPassiveEffects !== null) {1090    const priorityLevel = getCurrentPriorityLevel();1091    scheduleCallback(priorityLevel, () => {1092      flushPassiveEffects();1093      return null;1094    });1095  }1096  return null;1097}1098function commitRootImpl(root, expirationTime) {1099  flushPassiveEffects();1100  flushRenderPhaseStrictModeWarningsInDEV();1101  invariant(1102    workPhase !== RenderPhase && workPhase !== CommitPhase,1103    'Should not already be working.',1104  );1105  const finishedWork = root.current.alternate;1106  invariant(finishedWork !== null, 'Should have a work-in-progress root.');1107  // commitRoot never returns a continuation; it always finishes synchronously.1108  // So we can clear these now to allow a new callback to be scheduled.1109  root.callbackNode = null;1110  root.callbackExpirationTime = NoWork;1111  startCommitTimer();1112  // Update the first and last pending times on this root. The new first1113  // pending time is whatever is left on the root fiber.1114  const updateExpirationTimeBeforeCommit = finishedWork.expirationTime;1115  const childExpirationTimeBeforeCommit = finishedWork.childExpirationTime;1116  const firstPendingTimeBeforeCommit =1117    childExpirationTimeBeforeCommit > updateExpirationTimeBeforeCommit1118      ? childExpirationTimeBeforeCommit1119      : updateExpirationTimeBeforeCommit;1120  root.firstPendingTime = firstPendingTimeBeforeCommit;1121  if (firstPendingTimeBeforeCommit < root.lastPendingTime) {1122    // This usually means we've finished all the work, but it can also happen1123    // when something gets downprioritized during render, like a hidden tree.1124    root.lastPendingTime = firstPendingTimeBeforeCommit;1125  }1126  if (root === workInProgressRoot) {1127    // We can reset these now that they are finished.1128    workInProgressRoot = null;1129    workInProgress = null;1130    renderExpirationTime = NoWork;1131  } else {1132    // This indicates that the last root we worked on is not the same one that1133    // we're committing now. This most commonly happens when a suspended root1134    // times out.1135  }1136  // Get the list of effects.1137  let firstEffect;1138  if (finishedWork.effectTag > PerformedWork) {1139    // A fiber's effect list consists only of its children, not itself. So if1140    // the root has an effect, we need to add it to the end of the list. The1141    // resulting list is the set that would belong to the root's parent, if it1142    // had one; that is, all the effects in the tree including the root.1143    if (finishedWork.lastEffect !== null) {1144      finishedWork.lastEffect.nextEffect = finishedWork;1145      firstEffect = finishedWork.firstEffect;1146    } else {1147      firstEffect = finishedWork;1148    }1149  } else {1150    // There is no effect on the root.1151    firstEffect = finishedWork.firstEffect;1152  }1153  if (firstEffect !== null) {1154    const prevWorkPhase = workPhase;1155    workPhase = CommitPhase;1156    let prevInteractions: Set<Interaction> | null = null;1157    if (enableSchedulerTracing) {1158      prevInteractions = __interactionsRef.current;1159      __interactionsRef.current = root.memoizedInteractions;1160    }1161    // Reset this to null before calling lifecycles1162    ReactCurrentOwner.current = null;1163    // The commit phase is broken into several sub-phases. We do a separate pass1164    // of the effect list for each phase: all mutation effects come before all1165    // layout effects, and so on.1166    // The first phase a "before mutation" phase. We use this phase to read the1167    // state of the host tree right before we mutate it. This is where1168    // getSnapshotBeforeUpdate is called.1169    startCommitSnapshotEffectsTimer();1170    prepareForCommit(root.containerInfo);1171    nextEffect = firstEffect;1172    do {1173      if (__DEV__) {1174        invokeGuardedCallback(null, commitBeforeMutationEffects, null);1175        if (hasCaughtError()) {1176          invariant(nextEffect !== null, 'Should be working on an effect.');1177          const error = clearCaughtError();1178          captureCommitPhaseError(nextEffect, error);1179          nextEffect = nextEffect.nextEffect;1180        }1181      } else {1182        try {1183          commitBeforeMutationEffects();1184        } catch (error) {1185          invariant(nextEffect !== null, 'Should be working on an effect.');1186          captureCommitPhaseError(nextEffect, error);1187          nextEffect = nextEffect.nextEffect;1188        }1189      }1190    } while (nextEffect !== null);1191    stopCommitSnapshotEffectsTimer();1192    if (enableProfilerTimer) {1193      // Mark the current commit time to be shared by all Profilers in this1194      // batch. This enables them to be grouped later.1195      recordCommitTime();1196    }1197    // The next phase is the mutation phase, where we mutate the host tree.1198    startCommitHostEffectsTimer();1199    nextEffect = firstEffect;1200    do {1201      if (__DEV__) {1202        invokeGuardedCallback(null, commitMutationEffects, null);1203        if (hasCaughtError()) {1204          invariant(nextEffect !== null, 'Should be working on an effect.');1205          const error = clearCaughtError();1206          captureCommitPhaseError(nextEffect, error);1207          nextEffect = nextEffect.nextEffect;1208        }1209      } else {1210        try {1211          commitMutationEffects();1212        } catch (error) {1213          invariant(nextEffect !== null, 'Should be working on an effect.');1214          captureCommitPhaseError(nextEffect, error);1215          nextEffect = nextEffect.nextEffect;1216        }1217      }1218    } while (nextEffect !== null);1219    stopCommitHostEffectsTimer();1220    resetAfterCommit(root.containerInfo);1221    // The work-in-progress tree is now the current tree. This must come after1222    // the mutation phase, so that the previous tree is still current during1223    // componentWillUnmount, but before the layout phase, so that the finished1224    // work is current during componentDidMount/Update.1225    root.current = finishedWork;1226    // The next phase is the layout phase, where we call effects that read1227    // the host tree after it's been mutated. The idiomatic use case for this is1228    // layout, but class component lifecycles also fire here for legacy reasons.1229    startCommitLifeCyclesTimer();1230    nextEffect = firstEffect;1231    do {1232      if (__DEV__) {1233        invokeGuardedCallback(1234          null,1235          commitLayoutEffects,1236          null,1237          root,1238          expirationTime,1239        );1240        if (hasCaughtError()) {1241          invariant(nextEffect !== null, 'Should be working on an effect.');1242          const error = clearCaughtError();1243          captureCommitPhaseError(nextEffect, error);1244          nextEffect = nextEffect.nextEffect;1245        }1246      } else {1247        try {1248          commitLayoutEffects(root, expirationTime);1249        } catch (error) {1250          invariant(nextEffect !== null, 'Should be working on an effect.');1251          captureCommitPhaseError(nextEffect, error);1252          nextEffect = nextEffect.nextEffect;1253        }1254      }1255    } while (nextEffect !== null);1256    stopCommitLifeCyclesTimer();1257    nextEffect = null;1258    if (enableSchedulerTracing) {1259      __interactionsRef.current = ((prevInteractions: any): Set<Interaction>);1260    }1261    workPhase = prevWorkPhase;1262  } else {1263    // No effects.1264    root.current = finishedWork;1265    // Measure these anyway so the flamegraph explicitly shows that there were1266    // no effects.1267    // TODO: Maybe there's a better way to report this.1268    startCommitSnapshotEffectsTimer();1269    stopCommitSnapshotEffectsTimer();1270    if (enableProfilerTimer) {1271      recordCommitTime();1272    }1273    startCommitHostEffectsTimer();1274    stopCommitHostEffectsTimer();1275    startCommitLifeCyclesTimer();1276    stopCommitLifeCyclesTimer();1277  }1278  stopCommitTimer();1279  if (rootDoesHavePassiveEffects) {1280    // This commit has passive effects. Stash a reference to them. But don't1281    // schedule a callback until after flushing layout work.1282    rootDoesHavePassiveEffects = false;1283    rootWithPendingPassiveEffects = root;1284    pendingPassiveEffectsExpirationTime = expirationTime;1285  } else {1286    if (enableSchedulerTracing) {1287      // If there are no passive effects, then we can complete the pending1288      // interactions. Otherwise, we'll wait until after the passive effects1289      // are flushed.1290      finishPendingInteractions(root, expirationTime);1291    }1292  }1293  // Check if there's remaining work on this root1294  const remainingExpirationTime = root.firstPendingTime;1295  if (remainingExpirationTime !== NoWork) {1296    const currentTime = requestCurrentTime();1297    const priorityLevel = inferPriorityFromExpirationTime(1298      currentTime,1299      remainingExpirationTime,1300    );1301    scheduleCallbackForRoot(root, priorityLevel, remainingExpirationTime);1302  } else {1303    // If there's no remaining work, we can clear the set of already failed1304    // error boundaries.1305    legacyErrorBoundariesThatAlreadyFailed = null;1306  }1307  onCommitRoot(finishedWork.stateNode);1308  if (remainingExpirationTime === Sync) {1309    // Count the number of times the root synchronously re-renders without1310    // finishing. If there are too many, it indicates an infinite update loop.1311    if (root === rootWithNestedUpdates) {1312      nestedUpdateCount++;1313    } else {1314      nestedUpdateCount = 0;1315      rootWithNestedUpdates = root;1316    }1317  } else {1318    nestedUpdateCount = 0;1319  }1320  if (hasUncaughtError) {1321    hasUncaughtError = false;1322    const error = firstUncaughtError;1323    firstUncaughtError = null;1324    throw error;1325  }1326  if (workPhase === LegacyUnbatchedPhase) {1327    // This is a legacy edge case. We just committed the initial mount of1328    // a ReactDOM.render-ed root inside of batchedUpdates. The commit fired1329    // synchronously, but layout updates should be deferred until the end1330    // of the batch.1331    return null;1332  }1333  // If layout work was scheduled, flush it now.1334  flushImmediateQueue();1335  return null;1336}1337function commitBeforeMutationEffects() {1338  while (nextEffect !== null) {1339    if ((nextEffect.effectTag & Snapshot) !== NoEffect) {1340      setCurrentDebugFiberInDEV(nextEffect);1341      recordEffect();1342      const current = nextEffect.alternate;1343      commitBeforeMutationEffectOnFiber(current, nextEffect);1344      resetCurrentDebugFiberInDEV();1345    }1346    nextEffect = nextEffect.nextEffect;1347  }1348}1349function commitMutationEffects() {1350  // TODO: Should probably move the bulk of this function to commitWork.1351  while (nextEffect !== null) {1352    setCurrentDebugFiberInDEV(nextEffect);1353    const effectTag = nextEffect.effectTag;1354    if (effectTag & ContentReset) {1355      commitResetTextContent(nextEffect);1356    }1357    if (effectTag & Ref) {1358      const current = nextEffect.alternate;1359      if (current !== null) {1360        commitDetachRef(current);1361      }1362    }1363    // The following switch statement is only concerned about placement,1364    // updates, and deletions. To avoid needing to add a case for every possible1365    // bitmap value, we remove the secondary effects from the effect tag and1366    // switch on that value.1367    let primaryEffectTag = effectTag & (Placement | Update | Deletion);1368    switch (primaryEffectTag) {1369      case Placement: {1370        commitPlacement(nextEffect);1371        // Clear the "placement" from effect tag so that we know that this is1372        // inserted, before any life-cycles like componentDidMount gets called.1373        // TODO: findDOMNode doesn't rely on this any more but isMounted does1374        // and isMounted is deprecated anyway so we should be able to kill this.1375        nextEffect.effectTag &= ~Placement;1376        break;1377      }1378      case PlacementAndUpdate: {1379        // Placement1380        commitPlacement(nextEffect);1381        // Clear the "placement" from effect tag so that we know that this is1382        // inserted, before any life-cycles like componentDidMount gets called.1383        nextEffect.effectTag &= ~Placement;1384        // Update1385        const current = nextEffect.alternate;1386        commitWork(current, nextEffect);1387        break;1388      }1389      case Update: {1390        const current = nextEffect.alternate;1391        commitWork(current, nextEffect);1392        break;1393      }1394      case Deletion: {1395        commitDeletion(nextEffect);1396        break;1397      }1398    }1399    // TODO: Only record a mutation effect if primaryEffectTag is non-zero.1400    recordEffect();1401    resetCurrentDebugFiberInDEV();1402    nextEffect = nextEffect.nextEffect;1403  }1404}1405function commitLayoutEffects(1406  root: FiberRoot,1407  committedExpirationTime: ExpirationTime,1408) {1409  // TODO: Should probably move the bulk of this function to commitWork.1410  while (nextEffect !== null) {1411    setCurrentDebugFiberInDEV(nextEffect);1412    const effectTag = nextEffect.effectTag;1413    if (effectTag & (Update | Callback)) {1414      recordEffect();1415      const current = nextEffect.alternate;1416      commitLayoutEffectOnFiber(1417        root,1418        current,1419        nextEffect,1420        committedExpirationTime,1421      );1422    }1423    if (effectTag & Ref) {1424      recordEffect();1425      commitAttachRef(nextEffect);1426    }1427    if (effectTag & Passive) {1428      rootDoesHavePassiveEffects = true;1429    }1430    resetCurrentDebugFiberInDEV();1431    nextEffect = nextEffect.nextEffect;1432  }1433}1434export function flushPassiveEffects() {1435  if (rootWithPendingPassiveEffects === null) {1436    return false;1437  }1438  const root = rootWithPendingPassiveEffects;1439  const expirationTime = pendingPassiveEffectsExpirationTime;1440  rootWithPendingPassiveEffects = null;1441  pendingPassiveEffectsExpirationTime = NoWork;1442  let prevInteractions: Set<Interaction> | null = null;1443  if (enableSchedulerTracing) {1444    prevInteractions = __interactionsRef.current;1445    __interactionsRef.current = root.memoizedInteractions;1446  }1447  invariant(1448    workPhase !== RenderPhase && workPhase !== CommitPhase,1449    'Cannot flush passive effects while already rendering.',1450  );1451  const prevWorkPhase = workPhase;1452  workPhase = CommitPhase;1453  // Note: This currently assumes there are no passive effects on the root1454  // fiber, because the root is not part of its own effect list. This could1455  // change in the future.1456  let effect = root.current.firstEffect;1457  while (effect !== null) {1458    if (__DEV__) {1459      setCurrentDebugFiberInDEV(effect);1460      invokeGuardedCallback(null, commitPassiveHookEffects, null, effect);1461      if (hasCaughtError()) {1462        invariant(effect !== null, 'Should be working on an effect.');1463        const error = clearCaughtError();1464        captureCommitPhaseError(effect, error);1465      }1466      resetCurrentDebugFiberInDEV();1467    } else {1468      try {1469        commitPassiveHookEffects(effect);1470      } catch (error) {1471        invariant(effect !== null, 'Should be working on an effect.');1472        captureCommitPhaseError(effect, error);1473      }1474    }1475    effect = effect.nextEffect;1476  }1477  if (enableSchedulerTracing) {1478    __interactionsRef.current = ((prevInteractions: any): Set<Interaction>);1479    finishPendingInteractions(root, expirationTime);1480  }1481  workPhase = prevWorkPhase;1482  flushImmediateQueue();1483  // If additional passive effects were scheduled, increment a counter. If this1484  // exceeds the limit, we'll fire a warning.1485  nestedPassiveUpdateCount =1486    rootWithPendingPassiveEffects === null ? 0 : nestedPassiveUpdateCount + 1;1487  return true;1488}1489export function isAlreadyFailedLegacyErrorBoundary(instance: mixed): boolean {1490  return (1491    legacyErrorBoundariesThatAlreadyFailed !== null &&1492    legacyErrorBoundariesThatAlreadyFailed.has(instance)1493  );1494}1495export function markLegacyErrorBoundaryAsFailed(instance: mixed) {1496  if (legacyErrorBoundariesThatAlreadyFailed === null) {1497    legacyErrorBoundariesThatAlreadyFailed = new Set([instance]);1498  } else {1499    legacyErrorBoundariesThatAlreadyFailed.add(instance);1500  }1501}1502function prepareToThrowUncaughtError(error: mixed) {1503  if (!hasUncaughtError) {1504    hasUncaughtError = true;1505    firstUncaughtError = error;1506  }1507}1508export const onUncaughtError = prepareToThrowUncaughtError;1509function captureCommitPhaseErrorOnRoot(1510  rootFiber: Fiber,1511  sourceFiber: Fiber,1512  error: mixed,1513) {1514  const errorInfo = createCapturedValue(error, sourceFiber);1515  const update = createRootErrorUpdate(rootFiber, errorInfo, Sync);1516  enqueueUpdate(rootFiber, update);1517  const root = markUpdateTimeFromFiberToRoot(rootFiber, Sync);1518  if (root !== null) {1519    scheduleCallbackForRoot(root, ImmediatePriority, Sync);1520  }1521}1522export function captureCommitPhaseError(sourceFiber: Fiber, error: mixed) {1523  if (sourceFiber.tag === HostRoot) {1524    // Error was thrown at the root. There is no parent, so the root1525    // itself should capture it.1526    captureCommitPhaseErrorOnRoot(sourceFiber, sourceFiber, error);1527    return;1528  }1529  let fiber = sourceFiber.return;1530  while (fiber !== null) {1531    if (fiber.tag === HostRoot) {1532      captureCommitPhaseErrorOnRoot(fiber, sourceFiber, error);1533      return;1534    } else if (fiber.tag === ClassComponent) {1535      const ctor = fiber.type;1536      const instance = fiber.stateNode;1537      if (1538        typeof ctor.getDerivedStateFromError === 'function' ||1539        (typeof instance.componentDidCatch === 'function' &&1540          !isAlreadyFailedLegacyErrorBoundary(instance))1541      ) {1542        const errorInfo = createCapturedValue(error, sourceFiber);1543        const update = createClassErrorUpdate(1544          fiber,1545          errorInfo,1546          // TODO: This is always sync1547          Sync,1548        );1549        enqueueUpdate(fiber, update);1550        const root = markUpdateTimeFromFiberToRoot(fiber, Sync);1551        if (root !== null) {1552          scheduleCallbackForRoot(root, ImmediatePriority, Sync);1553        }1554        return;1555      }1556    }1557    fiber = fiber.return;1558  }1559}1560export function pingSuspendedRoot(1561  root: FiberRoot,1562  thenable: Thenable,1563  suspendedTime: ExpirationTime,1564) {1565  const pingCache = root.pingCache;1566  if (pingCache !== null) {1567    // The thenable resolved, so we no longer need to memoize, because it will1568    // never be thrown again.1569    pingCache.delete(thenable);1570  }1571  if (workInProgressRoot === root && renderExpirationTime === suspendedTime) {1572    // Received a ping at the same priority level at which we're currently1573    // rendering. Restart from the root. Don't need to schedule a ping because1574    // we're already working on this tree.1575    prepareFreshStack(root, renderExpirationTime);1576    return;1577  }1578  const lastPendingTime = root.lastPendingTime;1579  if (lastPendingTime < suspendedTime) {1580    // The root is no longer suspended at this time.1581    return;1582  }1583  const pingTime = root.pingTime;1584  if (pingTime !== NoWork && pingTime < suspendedTime) {1585    // There's already a lower priority ping scheduled.1586    return;1587  }1588  // Mark the time at which this ping was scheduled.1589  root.pingTime = suspendedTime;1590  const currentTime = requestCurrentTime();1591  const priorityLevel = inferPriorityFromExpirationTime(1592    currentTime,1593    suspendedTime,1594  );1595  scheduleCallbackForRoot(root, priorityLevel, suspendedTime);1596}1597export function retryTimedOutBoundary(boundaryFiber: Fiber) {1598  // The boundary fiber (a Suspense component) previously timed out and was1599  // rendered in its fallback state. One of the promises that suspended it has1600  // resolved, which means at least part of the tree was likely unblocked. Try1601  // rendering again, at a new expiration time.1602  const currentTime = requestCurrentTime();1603  const retryTime = computeExpirationForFiber(currentTime, boundaryFiber);1604  // TODO: Special case idle priority?1605  const priorityLevel = inferPriorityFromExpirationTime(currentTime, retryTime);1606  const root = markUpdateTimeFromFiberToRoot(boundaryFiber, retryTime);1607  if (root !== null) {1608    scheduleCallbackForRoot(root, priorityLevel, retryTime);1609  }1610}1611export function resolveRetryThenable(boundaryFiber: Fiber, thenable: Thenable) {1612  let retryCache: WeakSet<Thenable> | Set<Thenable> | null;1613  if (enableSuspenseServerRenderer) {1614    switch (boundaryFiber.tag) {1615      case SuspenseComponent:1616        retryCache = boundaryFiber.stateNode;1617        break;1618      case DehydratedSuspenseComponent:1619        retryCache = boundaryFiber.memoizedState;1620        break;1621      default:1622        invariant(1623          false,1624          'Pinged unknown suspense boundary type. ' +1625            'This is probably a bug in React.',1626        );1627    }1628  } else {1629    retryCache = boundaryFiber.stateNode;1630  }1631  if (retryCache !== null) {1632    // The thenable resolved, so we no longer need to memoize, because it will1633    // never be thrown again.1634    retryCache.delete(thenable);1635  }1636  retryTimedOutBoundary(boundaryFiber);1637}1638export function inferStartTimeFromExpirationTime(1639  root: FiberRoot,1640  expirationTime: ExpirationTime,1641) {1642  // We don't know exactly when the update was scheduled, but we can infer an1643  // approximate start time from the expiration time.1644  const earliestExpirationTimeMs = expirationTimeToMs(root.firstPendingTime);1645  // TODO: Track this on the root instead. It's more accurate, doesn't rely on1646  // assumptions about priority, and isn't coupled to Scheduler details.1647  return earliestExpirationTimeMs - LOW_PRIORITY_EXPIRATION;1648}1649function computeMsUntilTimeout(root, absoluteTimeoutMs) {1650  if (disableYielding) {1651    // Timeout immediately when yielding is disabled.1652    return 0;1653  }1654  // Find the earliest uncommitted expiration time in the tree, including1655  // work that is suspended. The timeout threshold cannot be longer than1656  // the overall expiration.1657  const earliestExpirationTimeMs = expirationTimeToMs(root.firstPendingTime);1658  if (earliestExpirationTimeMs < absoluteTimeoutMs) {1659    absoluteTimeoutMs = earliestExpirationTimeMs;1660  }1661  // Subtract the current time from the absolute timeout to get the number1662  // of milliseconds until the timeout. In other words, convert an absolute1663  // timestamp to a relative time. This is the value that is passed1664  // to `setTimeout`.1665  let msUntilTimeout = absoluteTimeoutMs - now();1666  return msUntilTimeout < 0 ? 0 : msUntilTimeout;1667}1668function checkForNestedUpdates() {1669  if (nestedUpdateCount > NESTED_UPDATE_LIMIT) {1670    nestedUpdateCount = 0;1671    rootWithNestedUpdates = null;1672    invariant(1673      false,1674      'Maximum update depth exceeded. This can happen when a component ' +1675        'repeatedly calls setState inside componentWillUpdate or ' +1676        'componentDidUpdate. React limits the number of nested updates to ' +1677        'prevent infinite loops.',1678    );1679  }1680  if (__DEV__) {1681    if (nestedPassiveUpdateCount > NESTED_PASSIVE_UPDATE_LIMIT) {1682      nestedPassiveUpdateCount = 0;1683      warning(1684        false,1685        'Maximum update depth exceeded. This can happen when a component ' +1686          "calls setState inside useEffect, but useEffect either doesn't " +1687          'have a dependency array, or one of the dependencies changes on ' +1688          'every render.',1689      );1690    }1691  }1692}1693function flushRenderPhaseStrictModeWarningsInDEV() {1694  if (__DEV__) {1695    ReactStrictModeWarnings.flushPendingUnsafeLifecycleWarnings();1696    ReactStrictModeWarnings.flushLegacyContextWarning();1697    if (warnAboutDeprecatedLifecycles) {1698      ReactStrictModeWarnings.flushPendingDeprecationWarnings();1699    }1700  }1701}1702function stopFinishedWorkLoopTimer() {1703  const didCompleteRoot = true;1704  stopWorkLoopTimer(interruptedBy, didCompleteRoot);1705  interruptedBy = null;1706}1707function stopInterruptedWorkLoopTimer() {1708  // TODO: Track which fiber caused the interruption.1709  const didCompleteRoot = false;1710  stopWorkLoopTimer(interruptedBy, didCompleteRoot);1711  interruptedBy = null;1712}1713function checkForInterruption(1714  fiberThatReceivedUpdate: Fiber,1715  updateExpirationTime: ExpirationTime,1716) {...Using AI Code Generation
1const { chromium } = require('playwright');2(async () => {3  const browser = await chromium.launch();4  const context = await browser.newContext();5  const page = await context.newPage();6  await page.waitForTimeout(1000);7  await page.evaluate(() => {8    window.stopFinishedWorkLoopTimer();9  });10  await browser.close();11})();12{13}14stopFinishedWorkLoopTimer()15const { chromium } = require('playwright');16(async () => {17  const browser = await chromium.launch();18  const context = await browser.newContext();19  const page = await context.newPage();20  await page.waitForTimeout(1000);21  await page.evaluate(() => {22    window.stopFinishedWorkLoopTimer();23  });24  await browser.close();25})();26startFinishedWorkLoopTimer()27getFinishedWorkLoopTimerResult()Using AI Code Generation
1import { chromium } from 'playwright';2import { stopFinishedWorkLoopTimer } from 'playwright/lib/server/browserContext';3(async () => {4  const browser = await chromium.launch();5  const context = await browser.newContext();6  stopFinishedWorkLoopTimer(context);7  const page = await context.newPage();8  await page.screenshot({ path: 'example.png' });9  await browser.close();10})();11const { chromium } = require('playwright');12(async () => {13  const browser = await chromium.launch();14  const context = await browser.newContext();15  const page = await context.newPage();16  await page.screenshot({ path: 'example.png' });17  await browser.close();18})();Using AI Code Generation
1const { Playwright } = require('@playwright/test');2Playwright.stopFinishedWorkLoopTimer();3const { Playwright } = require('@playwright/test');4Playwright.stopFinishedWorkLoopTimer();5const { Playwright } = require('@playwright/test');6Playwright.stopFinishedWorkLoopTimer();7const { Playwright } = require('@playwright/test');8Playwright.stopFinishedWorkLoopTimer();9const { Playwright } = require('@playwright/test');10Playwright.stopFinishedWorkLoopTimer();11const { Playwright } = require('@playwright/test');12Playwright.stopFinishedWorkLoopTimer();13const { Playwright } = require('@playwright/test');14Playwright.stopFinishedWorkLoopTimer();15const { Playwright } = require('@playwright/test');16Playwright.stopFinishedWorkLoopTimer();17const { Playwright } = require('@playwright/test');18Playwright.stopFinishedWorkLoopTimer();19const { Playwright } = require('@playwright/test');20Playwright.stopFinishedWorkLoopTimer();21const { Playwright } = require('@playwright/test');22Playwright.stopFinishedWorkLoopTimer();23const { Playwright } = require('@playwright/test');24Playwright.stopFinishedWorkLoopTimer();25const { Playwright } = require('@playwright/test');26Playwright.stopFinishedWorkLoopTimer();27const { Playwright } = require('@playwright/test');28Playwright.stopFinishedWorkLoopTimer();29const { Playwright } = require('@Using AI Code Generation
1const { chromium } = require('playwright');2const { startWorkLoopTimer, stopFinishedWorkLoopTimer } = require('playwright/lib/server/browserContext');3(async () => {4  const browser = await chromium.launch();5  const context = await browser.newContext();6  const page = await context.newPage();7  startWorkLoopTimer();8  await page.click('text=Get started');9  await page.waitForSelector('text=Playwright is a Node library to automate Chromium, Firefox and WebKit with a single API');10  stopFinishedWorkLoopTimer();11  await browser.close();12})();13const { chromium } = require('playwright');14const { startWorkLoopTimer, stopFinishedWorkLoopTimer } = require('playwright/lib/server/browserContext');15(async () => {16  const browser = await chromium.launch();17  const context = await browser.newContext();18  const page = await context.newPage();19  startWorkLoopTimer();20  await page.click('text=Get started');21  await page.waitForSelector('text=Playwright is a Node library to automate Chromium, Firefox and WebKit with a single API');22  stopFinishedWorkLoopTimer();23  await browser.close();24})();25const { chromium } = require('playwright');26const { startWorkLoopTimer, stopFinishedWorkLoopTimer } = require('playwright/lib/server/browserContext');27(async () => {28  const browser = await chromium.launch();29  const context = await browser.newContext();30  const page = await context.newPage();31  startWorkLoopTimer();32  await page.click('text=Get started');33  await page.waitForSelector('text=Playwright is a Node library to automate Chromium, Firefox and WebKit with a single API');34  stopFinishedWorkLoopTimer();35  await browser.close();36})();37const { chromium } = require('playwright');38const { startWorkLoopTimer, stopFinishedWorkLoopTimer } = require('playwright/lib/server/browserContext');39(async () => {40  const browser = await chromium.launch();41  const context = await browser.newContext();Using AI Code Generation
1const { PlaywrightInternal } = require('playwright-core/lib/server/playwright');2const playwright = new PlaywrightInternal();3playwright.stopFinishedWorkLoopTimer();4const { Playwright } = require('playwright-core');5const playwright = new Playwright();6playwright.stopFinishedWorkLoopTimer();7I am wondering if this is the same issue that is being addressed by the finished work loop timer. If so, is there a way to use the stopFinishedWorkLoopTimer() API to stop this timer so that I can avoid seeing these messages?Using AI Code Generation
1const { stopFinishedWorkLoopTimer } = require('playwright/lib/utils/traceViewer');2const { chromium } = require('playwright');3(async () => {4  const browser = await chromium.launch();5  const context = await browser.newContext();6  const page = await context.newPage();7  await page.screenshot({ path: 'example.png' });8  stopFinishedWorkLoopTimer();9  await browser.close();10})();11{12  "metadata": {13  },14    {15      "args": {16        "data": {17        },18      }19    },20    {21      "args": {22        "data": {23        }24      }25    },26    {27      "args": {28        "data": {Using AI Code Generation
1const { internal } = require('playwright');2const { stopFinishedWorkLoopTimer } = internal;3stopFinishedWorkLoopTimer();4const { test } = require('@playwright/test');5test('My test', async ({ page }) => {6});7const { internal } = require('playwright');8const { stopFinishedWorkLoopTimer } = internal;9stopFinishedWorkLoopTimer();10const { test } = require('@playwright/test');11test('My test', async ({ page }) => {12});13const { internal } = require('playwright');14const { stopFinishedWorkLoopTimer } = internal;15stopFinishedWorkLoopTimer();16const { test } = require('@playwright/test');17test('My test', async ({ page }) => {18});19const { internal } = require('playwright');20const { stopFinishedWorkLoopTimer } = internal;21stopFinishedWorkLoopTimer();22const { test } = require('@playwright/test');23test('My test', async ({ page }) => {24});25const { internal } = require('playwright');26const { stopFinishedWorkLoopTimer } = internal;27stopFinishedWorkLoopTimer();28const { test } = require('@playwright/test');29test('My test', async ({ page }) => {30});31const { internal } = require('playwright');32const { stopFinishedWorkLoopTimer } = internal;LambdaTest’s Playwright tutorial will give you a broader idea about the Playwright automation framework, its unique features, and use cases with examples to exceed your understanding of Playwright testing. This tutorial will give A to Z guidance, from installing the Playwright framework to some best practices and advanced concepts.
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