fix(android): Drop inflated app start for background-spawned processes on API 35+

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Fixes
 
+- Prevent inflated cold app start when the OS spawns the process in the background (e.g. FCM push) on API 35+ ([#5841](https://github.com/getsentry/sentry-java/pull/5841))
 - Avoid a CPU busy-loop when recording discarded log or metric envelopes under rate limiting ([#5835](https://github.com/getsentry/sentry-java/pull/5835))
   - `ClientReportRecorder` now reads the item count from the envelope item header instead of deserializing the payload, which under sustained rate limiting could pin CPU cores while repeatedly throwing exceptions
 

sentry-android-core/src/main/java/io/sentry/android/core/performance/AppStartMetrics.java

@@ -14,6 +14,7 @@
 import android.util.Log;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
 import androidx.annotation.VisibleForTesting;
 import io.sentry.IContinuousProfiler;
 import io.sentry.ISentryLifecycleToken;
@@ -208,6 +209,35 @@ public void setAppStartType(final @NotNull AppStartType appStartType) {
     }
   }
 
+  /**
+   * Whether {@link ApplicationStartInfo#getReason()} indicates the OS spawned the app process
+   * because of an intentional user interaction.
+   *
+   * @return true if the user actively launched the app, false if the app was launched in
+   *     background, and null if unknown.
+   */
+  @RequiresApi(api = Build.VERSION_CODES.VANILLA_ICE_CREAM)
+  private static @Nullable Boolean isForegroundStartReason(final int reason) {
+    switch (reason) {
+      case ApplicationStartInfo.START_REASON_LAUNCHER:
+      case ApplicationStartInfo.START_REASON_LAUNCHER_RECENTS:
+      case ApplicationStartInfo.START_REASON_START_ACTIVITY:
+        return true;
+      case ApplicationStartInfo.START_REASON_ALARM:
+      case ApplicationStartInfo.START_REASON_BACKUP:
+      case ApplicationStartInfo.START_REASON_BOOT_COMPLETE:
+      case ApplicationStartInfo.START_REASON_BROADCAST:
+      case ApplicationStartInfo.START_REASON_CONTENT_PROVIDER:
+      case ApplicationStartInfo.START_REASON_JOB:
+      case ApplicationStartInfo.START_REASON_PUSH:
+      case ApplicationStartInfo.START_REASON_SERVICE:
+        return false;
+      case ApplicationStartInfo.START_REASON_OTHER:
+      default:
+        return null;
+    }
+  }
+
   public boolean isAppLaunchedInForeground() {
     return appLaunchedInForeground.getValue();
   }
@@ -499,6 +529,7 @@ public void registerLifecycleCallbacks(final @NotNull Application application) {
               } else {
                 appStartType = AppStartType.WARM;
               }
+              appLaunchedInForeground.setValue(isForegroundStartReason(info.getReason()));
             }
           }
         } catch (RuntimeException ignored) {

sentry-android-core/src/test/java/io/sentry/android/core/performance/AppStartMetricsTestApi35.kt

@@ -1,11 +1,13 @@
 package io.sentry.android.core.performance
 
+import android.app.Activity
 import android.app.ActivityManager.RunningAppProcessInfo
 import android.app.Application
 import android.app.ApplicationStartInfo
 import android.os.Build
 import android.os.Handler
 import android.os.Looper
+import android.os.SystemClock
 import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import io.sentry.android.core.SentryShadowActivityManager
@@ -16,6 +18,7 @@ import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
 import kotlin.test.assertNull
+import kotlin.test.assertTrue
 import org.junit.Before
 import org.junit.runner.RunWith
 import org.mockito.kotlin.mock
@@ -263,6 +266,115 @@ class AppStartMetricsTestApi35 {
     assertNull(metrics.appStartReason)
   }
 
+  @Test
+  fun `background start reason marks app as not launched in foreground`() {
+    val mockStartInfo = mock<ApplicationStartInfo>()
+    whenever(mockStartInfo.startupState).thenReturn(ApplicationStartInfo.STARTUP_STATE_STARTED)
+    whenever(mockStartInfo.startType).thenReturn(ApplicationStartInfo.START_TYPE_COLD)
+    whenever(mockStartInfo.reason).thenReturn(ApplicationStartInfo.START_REASON_PUSH)
+    SentryShadowActivityManager.setHistoricalProcessStartReasons(listOf(mockStartInfo))
+    val metrics = AppStartMetrics.getInstance()
+
+    val app = ApplicationProvider.getApplicationContext<Application>()
+    metrics.registerLifecycleCallbacks(app)
+
+    assertFalse(metrics.isAppLaunchedInForeground)
+  }
+
+  @Test
+  fun `all background start reasons mark app as not launched in foreground`() {
+    val backgroundReasons =
+      listOf(
+        ApplicationStartInfo.START_REASON_ALARM,
+        ApplicationStartInfo.START_REASON_BACKUP,
+        ApplicationStartInfo.START_REASON_BOOT_COMPLETE,
+        ApplicationStartInfo.START_REASON_BROADCAST,
+        ApplicationStartInfo.START_REASON_CONTENT_PROVIDER,
+        ApplicationStartInfo.START_REASON_JOB,
+        ApplicationStartInfo.START_REASON_PUSH,
+        ApplicationStartInfo.START_REASON_SERVICE,
+      )
+
+    val app = ApplicationProvider.getApplicationContext<Application>()
+    for (reason in backgroundReasons) {
+      AppStartMetrics.getInstance().clear()
+      SentryShadowActivityManager.reset()
+
+      val mockStartInfo = mock<ApplicationStartInfo>()
+      whenever(mockStartInfo.startupState).thenReturn(ApplicationStartInfo.STARTUP_STATE_STARTED)
+      whenever(mockStartInfo.startType).thenReturn(ApplicationStartInfo.START_TYPE_COLD)
+      whenever(mockStartInfo.reason).thenReturn(reason)
+      SentryShadowActivityManager.setHistoricalProcessStartReasons(listOf(mockStartInfo))
+
+      AppStartMetrics.getInstance().registerLifecycleCallbacks(app)
+
+      assertFalse(
+        AppStartMetrics.getInstance().isAppLaunchedInForeground,
+        "reason $reason should not be launched in foreground",
+      )
+    }
+  }
+
+  @Test
+  fun `user-initiated start reason keeps app launched in foreground`() {
+    val mockStartInfo = mock<ApplicationStartInfo>()
+    whenever(mockStartInfo.startupState).thenReturn(ApplicationStartInfo.STARTUP_STATE_STARTED)
+    whenever(mockStartInfo.startType).thenReturn(ApplicationStartInfo.START_TYPE_COLD)
+    whenever(mockStartInfo.reason).thenReturn(ApplicationStartInfo.START_REASON_LAUNCHER)
+    SentryShadowActivityManager.setHistoricalProcessStartReasons(listOf(mockStartInfo))
+    SentryShadowActivityManager.setImportance(RunningAppProcessInfo.IMPORTANCE_FOREGROUND)
+    val metrics = AppStartMetrics.getInstance()
+
+    val app = ApplicationProvider.getApplicationContext<Application>()
+    metrics.registerLifecycleCallbacks(app)
+
+    assertTrue(metrics.isAppLaunchedInForeground)
+  }
+
+  @Test
+  fun `unknown start reason falls back to foreground importance check`() {
+    val mockStartInfo = mock<ApplicationStartInfo>()
+    whenever(mockStartInfo.startupState).thenReturn(ApplicationStartInfo.STARTUP_STATE_STARTED)
+    whenever(mockStartInfo.startType).thenReturn(ApplicationStartInfo.START_TYPE_COLD)
+    whenever(mockStartInfo.reason).thenReturn(ApplicationStartInfo.START_REASON_OTHER)
+    SentryShadowActivityManager.setHistoricalProcessStartReasons(listOf(mockStartInfo))
+    SentryShadowActivityManager.setImportance(RunningAppProcessInfo.IMPORTANCE_FOREGROUND)
+    val metrics = AppStartMetrics.getInstance()
+
+    val app = ApplicationProvider.getApplicationContext<Application>()
+    metrics.registerLifecycleCallbacks(app)
+
+    assertTrue(metrics.isAppLaunchedInForeground)
+  }
+
+  @Test
+  fun `background-spawned start is re-classified as warm on the first activity`() {
+    val mockStartInfo = mock<ApplicationStartInfo>()
+    whenever(mockStartInfo.startupState).thenReturn(ApplicationStartInfo.STARTUP_STATE_STARTED)
+    whenever(mockStartInfo.startType).thenReturn(ApplicationStartInfo.START_TYPE_COLD)
+    whenever(mockStartInfo.reason).thenReturn(ApplicationStartInfo.START_REASON_PUSH)
+    SentryShadowActivityManager.setHistoricalProcessStartReasons(listOf(mockStartInfo))
+    val metrics = AppStartMetrics.getInstance()
+    // App start span anchored at background process creation.
+    metrics.appStartTimeSpan.setStartedAt(42)
+
+    val app = ApplicationProvider.getApplicationContext<Application>()
+    metrics.registerLifecycleCallbacks(app)
+
+    assertFalse(metrics.isAppLaunchedInForeground)
+    assertEquals(AppStartMetrics.AppStartType.COLD, metrics.appStartType)
+
+    // User opens the app 20s later (under the 1-minute warm threshold).
+    val activityCreatedUptimeMs = 20_000L
+    SystemClock.setCurrentTimeMillis(activityCreatedUptimeMs)
+    metrics.onActivityCreated(mock<Activity>(), null)
+
+    // Re-classified as a warm start re-anchored at activity creation.
+    assertEquals(AppStartMetrics.AppStartType.WARM, metrics.appStartType)
+    assertTrue(metrics.isAppLaunchedInForeground)
+    assertEquals(activityCreatedUptimeMs, metrics.appStartTimeSpan.startUptimeMs)
+  }
+
   private fun waitForMainLooperIdle() {
     Handler(Looper.getMainLooper()).post {}
     Shadows.shadowOf(Looper.getMainLooper()).idle()