Android RN SDK calls Display.getSupportedModes() on every frame while collecting JS refresh rate

[ivan-moego]

Stack trace

ApplicationNotResponding: ANR
libart 0x037e790 art::gc::collector::MarkCompact::RunPhases
libart 0x03e71bc art::gc::collector::GarbageCollector::Run
libart 0x03ea5d4 art::gc::Heap::CollectGarbageInternal
libart 0x0594ee0 art::gc::Heap::AllocateInternalWithGc::lambda::operator
libart 0x02ef2b8 art::gc::Heap::AllocateInternalWithGc
libart 0x040d0b0 artAllocObjectFromCodeInitializedTLAB
libart 0x02c03bc art_quick_alloc_object_initialized_tlab
base.apk 0x22fc090 android.view.Display.filteredSupportedModes
stream (StreamSupport.java:69)
stream (Arrays.java:5880)
stream (Arrays.java:5861)
filteredSupportedModes (Display.java:1618)
getSupportedModes (Display.java:1584)
getMaxDisplayRefreshRate (DdSdkImplementation.kt:409)
normalizeFrameTime (DdSdkImplementation.kt:386)
normalizeFrameTime$default (DdSdkImplementation.kt:377)
buildFrameTimeCallback$lambda$8 (DdSdkImplementation.kt:354)
$r8$lambda$ZyVYPQuvXJRpX5_VsL4-xb-cqsg (unavailable:0)
invoke (D8$$SyntheticClass:0)
doFrame (FrameRateProvider.kt:40)
run (Choreographer.java:1959)
run (Choreographer.java:1970)
doCallbacks (Choreographer.java:1423)
doFrame (Choreographer.java:1338)
run (Choreographer.java:1930)
handleCallback (Handler.java:1070)
dispatchMessage (Handler.java:125)
dispatchMessage (Looper.java:358)
loopOnce (Looper.java:288)
loop (Looper.java:392)
main (ActivityThread.java:10346)
invoke
run (RuntimeInit.java:638)
main (ZygoteInit.java:972)

Thread: main
libart 0x037e790 art::gc::collector::MarkCompact::RunPhases
libart 0x03e71bc art::gc::collector::GarbageCollector::Run
libart 0x03ea5d4 art::gc::Heap::CollectGarbageInternal
libart 0x0594ee0 art::gc::Heap::AllocateInternalWithGc::lambda::operator
libart 0x02ef2b8 art::gc::Heap::AllocateInternalWithGc
libart 0x040d0b0 artAllocObjectFromCodeInitializedTLAB
libart 0x02c03bc art_quick_alloc_object_initialized_tlab
base.apk 0x22fc090 android.view.Display.filteredSupportedModes
stream (StreamSupport.java:69)
stream (Arrays.java:5880)
stream (Arrays.java:5861)
filteredSupportedModes (Display.java:1618)
getSupportedModes (Display.java:1584)
getMaxDisplayRefreshRate (DdSdkImplementation.kt:409)
normalizeFrameTime (DdSdkImplementation.kt:386)
normalizeFrameTime$default (DdSdkImplementation.kt:377)
buildFrameTimeCallback$lambda$8 (DdSdkImplementation.kt:354)
$r8$lambda$ZyVYPQuvXJRpX5_VsL4-xb-cqsg (unavailable:0)
invoke (D8$$SyntheticClass:0)
doFrame (FrameRateProvider.kt:40)
run (Choreographer.java:1959)
run (Choreographer.java:1970)
doCallbacks (Choreographer.java:1423)
doFrame (Choreographer.java:1338)
run (Choreographer.java:1930)
handleCallback (Handler.java:1070)
dispatchMessage (Handler.java:125)
dispatchMessage (Looper.java:358)
loopOnce (Looper.java:288)
loop (Looper.java:392)
main (ActivityThread.java:10346)
invoke
run (RuntimeInit.java:638)
main (ZygoteInit.java:972)

Reproduction steps

No response

Volume

1/5000

Affected SDK versions

3.4.0

Latest working SDK version

3.4.0

Does the crash manifest in the latest SDK version?

Yes

React Native Version

0.77.3

Package.json Contents

No response

iOS Setup

No response

Android Setup

No response

Device Information

Android 16，Samsung SM-X518U

Other relevant information

No response

[ivan-moego]

Relevant code path

In DdSdkImplementation.kt:

fun normalizeFrameTime(
    frameTimeSeconds: Double,
    context: Context,
    fpsBudget: Double? = null,
    deviceDisplayFps: Double? = null,
): Double {
    val maxDeviceDisplayHz = deviceDisplayFps ?: getMaxDisplayRefreshRate(context) ?: 60.0
    ...
}

private fun getMaxDisplayRefreshRate(context: Context?): Double {
    val dm = context?.getSystemService(Context.DISPLAY_SERVICE) as? DisplayManager ?: return 60.0
    val display: Display = dm.getDisplay(Display.DEFAULT_DISPLAY) ?: return DEFAULT_REFRESH_HZ

    return display.supportedModes.maxOfOrNull { it.refreshRate.toDouble() } ?: DEFAULT_REFRESH_HZ
}

Since normalizeFrameTime() is called from FpsFrameCallback.doFrame, display.supportedModes can be queried once per frame.

Expected behavior

The maximum supported display refresh rate should be cached, or computed outside of the per-frame hot path.
The max supported refresh rate for the default display is effectively stable for this use case, and querying it once during SDK initialization or the first frame callback should be enough.

Workaround

We applied a local pnpm patch that caches the value:

@Volatile
private var maxDisplayRefreshRate: Double? = null

private fun getCachedMaxDisplayRefreshRate(context: Context?): Double {
    maxDisplayRefreshRate?.let { return it }

    return getMaxDisplayRefreshRate(context).also {
        maxDisplayRefreshRate = it
    }
}

and then changed:

val maxDeviceDisplayHz = deviceDisplayFps ?: getCachedMaxDisplayRefreshRate(context) ?: 60.0

This keeps rum.measure.view.refresh_rate reporting enabled while avoiding repeated Display.getSupportedModes() calls on the frame callback path.

[sbarrio]

Hi @ivan-moego, thanks for reaching out.

Indeed this can be optimized and cached. I've just created a PR applying your fix here: #1315

It will be released alongside the next SDK release. I'll ping you back when that happens.