Background Build UUID extraction

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## TBD
+
+### Enhancements
+
+* Build UUIDs derived from dex file signatures no longer block NDK startup, reducing the overall startup time.
+  [#2401](https://github.com/bugsnag/bugsnag-android/pull/2401)
+
 ## 6.25.0 (2026-03-02)
 
 ### Enhancements

bugsnag-android-core/src/main/java/com/bugsnag/android/App.kt

@@ -50,7 +50,8 @@ open class App internal constructor(
     var versionCode: Number?
 ) : JsonStream.Streamable {
 
-    private var buildUuidProvider: Provider<String?>? = buildUuid
+    @get:JvmName("getBuildUuidProvider\$internal")
+    internal var buildUuidProvider: Provider<String?>? = buildUuid
 
     var buildUuid: String? = null
         get() = field ?: buildUuidProvider?.getOrNull()

bugsnag-android-core/src/main/java/com/bugsnag/android/Client.java

@@ -427,6 +427,25 @@ void setupNdkPlugin() {
         clientObservable.postNdkInstall(immutableConfig, lastRunInfoPath, crashes);
         syncInitialState();
         clientObservable.postNdkDeliverPending();
+
+        // If the buildUuid is still being computed (DexBuildIdGenerator running on IO thread),
+        // schedule a deferred SynchronizeState so the NDK layer picks up the value once ready.
+        Provider<String> buildUuid = immutableConfig.getBuildUuid();
+        if (buildUuid != null && !buildUuid.isComplete()) {
+            try {
+                bgTaskService.submitTask(TaskType.IO, new Runnable() {
+                    @Override
+                    public void run() {
+                        // This blocks on the IO thread until dex generation finishes,
+                        // then syncs the result to the NDK layer.
+                        immutableConfig.getBuildUuid().getOrNull();
+                        clientObservable.postSynchronizeState();
+                    }
+                });
+            } catch (RejectedExecutionException exc) {
+                logger.w("Failed to schedule deferred NDK build UUID sync", exc);
+            }
+        }
     }
 
     private boolean setupNdkDirectory() {

bugsnag-android-core/src/main/java/com/bugsnag/android/ClientObservable.kt

@@ -18,7 +18,8 @@ internal class ClientObservable : BaseObservable() {
                 conf.apiKey,
                 conf.enabledErrorTypes.ndkCrashes,
                 conf.appVersion,
-                conf.buildUuid?.getOrNull(),
+                if (conf.buildUuid?.isComplete == true) conf.buildUuid.getOrNull()
+                else null,
                 conf.releaseStage,
                 lastRunInfoPath,
                 consecutiveLaunchCrashes,

bugsnag-android-core/src/main/java/com/bugsnag/android/NativeInterface.java

@@ -2,6 +2,7 @@
 
 import com.bugsnag.android.internal.ImmutableConfig;
 import com.bugsnag.android.internal.JsonHelper;
+import com.bugsnag.android.internal.dag.Provider;
 
 import android.annotation.SuppressLint;
 
@@ -114,14 +115,20 @@ public static Map<String, String> getUser() {
     @NonNull
     @SuppressWarnings("unused")
     public static Map<String, Object> getApp() {
-        HashMap<String, Object> data = new HashMap<>();
         AppDataCollector source = getClient().getAppDataCollector();
         AppWithState app = source.generateAppWithState();
+
+        Provider<String> buildUuidProvider = app.getBuildUuidProvider$internal();
+        String buildUuid = buildUuidProvider != null && buildUuidProvider.isComplete()
+                ? buildUuidProvider.getOrNull()
+                : null;
+
+        HashMap<String, Object> data = new HashMap<>();
         data.put("version", app.getVersion());
         data.put("releaseStage", app.getReleaseStage());
         data.put("id", app.getId());
         data.put("type", app.getType());
-        data.put("buildUUID", app.getBuildUuid());
+        data.put("buildUUID", buildUuid);
         data.put("duration", app.getDuration());
         data.put("durationInForeground", app.getDurationInForeground());
         data.put("versionCode", app.getVersionCode());

bugsnag-android-core/src/test/java/com/bugsnag/android/ClientObservableTest.kt

@@ -1,7 +1,11 @@
 package com.bugsnag.android
 
 import com.bugsnag.android.internal.StateObserver
+import com.bugsnag.android.internal.convertToImmutableConfig
+import com.bugsnag.android.internal.dag.RunnableProvider
+import com.bugsnag.android.internal.dag.ValueProvider
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
 import org.junit.Assert.assertTrue
 import org.junit.Test
 
@@ -22,12 +26,61 @@ class ClientObservableTest {
 
     @Test
     fun postNdkInstall() {
-        clientObservable.postNdkInstall(BugsnagTestUtils.generateImmutableConfig(), "/foo", 0)
         clientObservable.addObserver(
             StateObserver {
                 assertTrue(it is StateEvent.Install)
             }
         )
+        clientObservable.postNdkInstall(BugsnagTestUtils.generateImmutableConfig(), "/foo", 0)
+    }
+
+    @Test
+    fun postNdkInstallBuildUuidNull() {
+        // When buildUuid is null, Install event should have null buildUuid
+        val config = BugsnagTestUtils.generateImmutableConfig()
+        var installEvent: StateEvent.Install? = null
+        clientObservable.addObserver {
+            if (it is StateEvent.Install) installEvent = it
+        }
+        clientObservable.postNdkInstall(config, "/foo", 0)
+        assertNull(installEvent?.buildUuid)
+    }
+
+    @Test
+    fun postNdkInstallBuildUuidComplete() {
+        // When buildUuid is a ValueProvider (already complete), Install should include it
+        val config = convertToImmutableConfig(
+            BugsnagTestUtils.generateConfiguration(),
+            ValueProvider("test-uuid")
+        )
+        var installEvent: StateEvent.Install? = null
+        clientObservable.addObserver(
+            StateObserver {
+                if (it is StateEvent.Install) installEvent = it
+            }
+        )
+        clientObservable.postNdkInstall(config, "/foo", 0)
+        assertEquals("test-uuid", installEvent?.buildUuid)
+    }
+
+    @Test
+    fun postNdkInstallBuildUuidPending() {
+        // When buildUuid is a pending RunnableProvider, Install should have null buildUuid
+        val pendingProvider = object : RunnableProvider<String?>() {
+            override fun invoke(): String? = "deferred-uuid"
+        }
+        val config = convertToImmutableConfig(
+            BugsnagTestUtils.generateConfiguration(),
+            pendingProvider
+        )
+        var installEvent: StateEvent.Install? = null
+        clientObservable.addObserver(
+            StateObserver {
+                if (it is StateEvent.Install) installEvent = it
+            }
+        )
+        clientObservable.postNdkInstall(config, "/foo", 0)
+        assertNull(installEvent?.buildUuid)
     }
 
     @Test

bugsnag-plugin-android-apphang/src/androidTest/java/com/bugsnag/android/LooperMonitorThreadTest.kt

@@ -52,25 +52,6 @@ class LooperMonitorThreadTest {
         assertEquals("no AppHangs expected", 0, appHangCount)
     }
 
-    @Test
-    fun testBelowThresholdEvents() {
-        val countDownLatch = CountDownLatch(10)
-        val task = object : Runnable {
-            override fun run() {
-                JThread.sleep(APP_HANG_THRESHOLD / 2)
-                countDownLatch.countDown()
-
-                if (countDownLatch.count > 0) {
-                    handler.postDelayed(this, 1L)
-                }
-            }
-        }
-        handler.postDelayed(task, 1)
-
-        countDownLatch.await()
-        assertEquals("no AppHangs expected", 0, appHangCount)
-    }
-
     @Test
     fun appHang() {
         val countDownLatch = CountDownLatch(1)