ReactFiberAsyncAction.js — react Source File

Source Code

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */

import type {
  Thenable,
  FulfilledThenable,
  RejectedThenable,
} from 'shared/ReactTypes';
import type {Lane} from './ReactFiberLane';
import type {Transition} from 'react/src/ReactStartTransition';

import {
  requestTransitionLane,
  ensureScheduleIsScheduled,
} from './ReactFiberRootScheduler';
import {NoLane} from './ReactFiberLane';
import {
  hasScheduledTransitionWork,
  clearAsyncTransitionTimer,
} from './ReactProfilerTimer';
import {
  enableComponentPerformanceTrack,
  enableProfilerTimer,
  enableDefaultTransitionIndicator,
} from 'shared/ReactFeatureFlags';
import {clearEntangledAsyncTransitionTypes} from './ReactFiberTransitionTypes';

import noop from 'shared/noop';
import reportGlobalError from 'shared/reportGlobalError';

// If there are multiple, concurrent async actions, they are entangled. All
// transition updates that occur while the async action is still in progress
// are treated as part of the action.
//
// The ideal behavior would be to treat each async function as an independent
// action. However, without a mechanism like AsyncContext, we can't tell which
// action an update corresponds to. So instead, we entangle them all into one.

// The listeners to notify once the entangled scope completes.
let currentEntangledListeners: Array<() => mixed> | null = null;
// The number of pending async actions in the entangled scope.
let currentEntangledPendingCount: number = 0;
// The transition lane shared by all updates in the entangled scope.
let currentEntangledLane: Lane = NoLane;
// A thenable that resolves when the entangled scope completes. It does not
// resolve to a particular value because it's only used for suspending the UI
// until the async action scope has completed.
let currentEntangledActionThenable: Thenable<void> | null = null;

// Track the default indicator for every root. undefined means we haven't
// had any roots registered yet. null means there's more than one callback.
// If there's more than one callback we bailout to not supporting isomorphic
// default indicators.
let isomorphicDefaultTransitionIndicator:
// ... (204 more lines)