[Flight] Flush performance track once we have no more pending chunks#33719
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sebmarkbage merged 2 commits intofacebook:mainfrom Jul 7, 2025
Merged
[Flight] Flush performance track once we have no more pending chunks#33719sebmarkbage merged 2 commits intofacebook:mainfrom
sebmarkbage merged 2 commits intofacebook:mainfrom
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Stacked on #33718. Alternative to #33716.
The issue with flushing the Server Components track in its current form is that we need to decide how long to wait before flushing whatever we have. That's because the root's end time will be determined by the end time of that last child.
However, if a child isn't actually used then we don't necessarily need to include it in the Server Components track since it wasn't blocking the initial render.
This waits for 100ms after the last pending chunk is resolved and if nothing is invoking any more lazy initializers after that then we log the Server Components track with the information we have at that point. We also don't eagerly initialize any chunks that wasn't already initialized so if nothing was rendered, then nothing will be logged.
This is somewhat an artifact of the current visualization. If we did another transposed form we wouldn't necessarily need to wait until the end and can log things as they're discovered.