> ## Documentation Index
> Fetch the complete documentation index at: https://docs.basset.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# displayList.churn

> Whether SwiftUI's rendered output is changing, sampled from the hosting view's display list

Samples SwiftUI's hosting view display list directly, by reflection. One
reading per periodic window, reporting whether the display list changed at
all — including the windows before any SwiftUI host exists on screen.

| | |
| - | - |
| [Delivery](/instruments/metadata) | stream, interval |
| Mechanism | reflection |
| [Requires](/instruments/metadata) | iOS 17+, basset 0.1.1+ |

Real output from `basset request get`, captured against a running app —
trimmed from 18 windows to the moment a host appears and the mechanism starts
reporting real values:

```
CAPTURED                  ELAPSED  INSTRUMENT

launch 12789531692424341857
2026-08-23T15:05:12.639Z  +15.0s   swiftui.displayList.churn(swiftUIDisplayList)
├─ windowNanoseconds       999922750
├─ mechanismStatus         no swiftui host on screen
├─ hostCount               0
└─ displayListChangeCount  0
2026-08-23T15:05:13.640Z  +16.0s   swiftui.displayList.churn(swiftUIDisplayList)
├─ windowNanoseconds       1001122166
├─ mechanismStatus         ok
├─ hostCount               1
├─ ivarPathGeneration      26
├─ displayListItemCount    1
├─ displayListSeed         159
└─ displayListChangeCount  0
2026-08-23T15:05:14.639Z  +17.0s   swiftui.displayList.churn(swiftUIDisplayList)
├─ windowNanoseconds       998379084
├─ mechanismStatus         ok
├─ hostCount               1
├─ ivarPathGeneration      26
├─ displayListItemCount    1
├─ displayListSeed         299
└─ displayListChangeCount  1
```


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.