Android crash: NoSuchElementException in ConcurrentHashMap inside DatadogRumMonitor

[gellertkacso]

Description

We're seeing an Android-only crash (is_crash: true) originating entirely within the Datadog RUM SDK internals. The crash is a java.util.NoSuchElementException thrown from ConcurrentHashMap$EntryIterator.next, triggered during RUM scope processing inside DatadogRumMonitor.

This appears to be a concurrency issue where a ConcurrentHashMap is being iterated while another thread modifies it.

Environment

• datadog_flutter_plugin: 3.0.1 (latest on pub.dev)
• Platform: Android 15 and Android 16 (multiple devices)
• Flutter: 3.29.x
• Affected devices: Samsung Galaxy S24, OnePlus 10 Pro (not device-specific)

Stack Trace

java.util.NoSuchElementException
	at java.util.concurrent.ConcurrentHashMap$EntryIterator.next(ConcurrentHashMap.java:3506)
	at java.util.concurrent.ConcurrentHashMap$EntryIterator.next(ConcurrentHashMap.java:3496)
	at Ev0.h(Unknown Source:13)
	at Fv0.u(Unknown Source:19)
	at Cv0.u(Unknown Source:0)
	at com.datadog.android.rum.internal.domain.scope.g.X(Unknown Source:8)
	at com.datadog.android.rum.internal.domain.scope.g.h0(Unknown Source:8)
	at com.datadog.android.rum.internal.domain.scope.g.a(Unknown Source:12)
	at com.datadog.android.rum.internal.domain.scope.f.l(Unknown Source:78)
	at com.datadog.android.rum.internal.domain.scope.f.a(Unknown Source:43)
	at com.datadog.android.rum.internal.domain.scope.e.a(Unknown Source:38)
	at com.datadog.android.rum.internal.domain.scope.b.d(Unknown Source:18)
	at com.datadog.android.rum.internal.domain.scope.b.a(Unknown Source:114)
	at com.datadog.android.rum.internal.monitor.DatadogRumMonitor$c.c(Unknown Source:14)
	at com.datadog.android.rum.internal.monitor.DatadogRumMonitor$c.invoke(Unknown Source:0)
	at hW.a(Unknown Source:35)
	at com.datadog.android.rum.internal.monitor.DatadogRumMonitor.Q(Unknown Source:52)
	at com.datadog.android.rum.internal.monitor.DatadogRumMonitor.P(Unknown Source:13)
	at com.datadog.android.rum.internal.monitor.DatadogRumMonitor.C(Unknown Source:0)
	at BD.run(Unknown Source:4)
	at yG0.run(Unknown Source:2)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1156)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:651)
	at java.lang.Thread.run(Thread.java:1119)

Impact

• The crash kills the app (is_crash: true)
• Occurs on the main view during normal usage (no specific user action triggers it)
• Affects multiple users across different Android devices and OS versions
• The entire stack trace is within Datadog SDK internals — no application code involved

Expected Behavior

The SDK should not crash the host application. Concurrent access to internal data structures should be properly synchronized.

[fuzzybinary]

Hi @gellertkacso,

We'll definitely look into this. Is is possible you can get us a deobfuscated stack trace? That would help us figure out what's going on and whether we've seen this issue before.

Thanks!

[fuzzybinary]

Hi @gellertkacso ,

Do you have a mapper installed? This portion of the stack trace:

at Ev0.h(Unknown Source:13)
at Fv0.u(Unknown Source:19)
at Cv0.u(Unknown Source:0)

Looks like it might be in you're code, as part of callback from Datadog.