Function pingSuspendedRoot

packages/react-reconciler/src/ReactFiberWorkLoop.js:4777–4850

(
  root: FiberRoot,
  wakeable: Wakeable,
  pingedLanes: Lanes,
)

}

function pingSuspendedRoot(
  root: FiberRoot,
  wakeable: Wakeable,
  pingedLanes: Lanes,
) {
  const pingCache = root.pingCache;
  if (pingCache !== null) {
    // The wakeable resolved, so we no longer need to memoize, because it will
    // never be thrown again.
    pingCache.delete(wakeable);
  }

  markRootPinged(root, pingedLanes);

  if (enableProfilerTimer && enableComponentPerformanceTrack) {
    startPingTimerByLanes(pingedLanes);
  }

  warnIfSuspenseResolutionNotWrappedWithActDEV(root);

  if (
    workInProgressRoot === root &&
    isSubsetOfLanes(workInProgressRootRenderLanes, pingedLanes)
  ) {
    // Received a ping at the same priority level at which we're currently
    // rendering. We might want to restart this render. This should mirror
    // the logic of whether or not a root suspends once it completes.
    // TODO: If we're rendering sync either due to Sync, Batched or expired,
    // we should probably never restart.
    // TODO: Attach different listeners depending on whether the listener was
    // attached during prerendering. Prerender pings should not interrupt
    // normal renders.

    // If we're suspended with delay, or if it's a retry, we'll always suspend
    // so we can always restart.
    if (
      workInProgressRootExitStatus === RootSuspendedWithDelay ||
      (workInProgressRootExitStatus === RootSuspended &&
        includesOnlyRetries(workInProgressRootRenderLanes) &&
        now() - globalMostRecentFallbackTime < FALLBACK_THROTTLE_MS)
    ) {
      // Force a restart from the root by unwinding the stack. Unless this is
      // being called from the render phase, because that would cause a crash.
      if ((executionContext & RenderContext) === NoContext) {
        prepareFreshStack(root, NoLanes);
      } else {
        // TODO: If this does happen during the render phase, we should throw
        // the special internal exception that we use to interrupt the stack for
        // selective hydration. That was temporarily reverted but we once we add
        // it back we can use it here.
      }
    } else {
      // Even though we can't restart right now, we might get an
      // opportunity later. So we mark this render as having a ping.
      workInProgressRootPingedLanes = mergeLanes(
        workInProgressRootPingedLanes,
        pingedLanes,
      );