Function prepareFreshStack

packages/react-reconciler/src/ReactFiberWorkLoop.js:1932–2202

(root: FiberRoot, lanes: Lanes)

}

function prepareFreshStack(root: FiberRoot, lanes: Lanes): Fiber {
  if (enableProfilerTimer && enableComponentPerformanceTrack) {
    // The order of tracks within a group are determined by the earliest start time.
    // Are tracks should show up in priority order and we should ideally always show
    // every track. This is a hack to ensure that we're displaying all tracks in the
    // right order. Ideally we could do this only once but because calls that aren't
    // recorded aren't considered for ordering purposes, we need to keep adding these
    // over and over again in case recording has just started. We can't tell when
    // recording starts.
    markAllLanesInOrder();

    const previousRenderStartTime = renderStartTime;
    // Starting a new render. Log the end of any previous renders and the
    // blocked time before the render started.
    recordRenderTime();
    // If this was a restart, e.g. due to an interrupting update, then there's no space
    // in the track to log the cause since we'll have rendered all the way up until the
    // restart so we need to clamp that.
    if (
      workInProgressRootRenderLanes !== NoLanes &&
      previousRenderStartTime > 0
    ) {
      setCurrentTrackFromLanes(workInProgressRootRenderLanes);
      if (
        workInProgressRootExitStatus === RootSuspended ||
        workInProgressRootExitStatus === RootSuspendedWithDelay
      ) {
        // If the root was already suspended when it got interrupted and restarted,
        // then this is considered a prewarm and not an interrupted render because
        // we couldn't have shown anything anyway so it's not a bad thing that we
        // got interrupted.
        logSuspendedRenderPhase(
          previousRenderStartTime,
          renderStartTime,
          lanes,
          workInProgressUpdateTask,
        );
      } else {
        logInterruptedRenderPhase(
          previousRenderStartTime,
          renderStartTime,
          lanes,
          workInProgressUpdateTask,
        );
      }
      finalizeRender(workInProgressRootRenderLanes, renderStartTime);
    }
    const previousUpdateTask = workInProgressUpdateTask;

    workInProgressUpdateTask = null;
    if (isGestureRender(lanes)) {
      workInProgressUpdateTask = gestureUpdateTask;
      const clampedUpdateTime =
        gestureUpdateTime >= 0 && gestureUpdateTime < gestureClampTime
          ? gestureClampTime
          : gestureUpdateTime;
      const clampedEventTime =
        gestureEventTime >= 0 && gestureEventTime < gestureClampTime