[DRAFT] Fireperf AQS changes

firebase-perf/firebase-perf.gradle

@@ -72,13 +72,15 @@ android {
         buildConfigField("String", "TRANSPORT_LOG_SRC", "String.valueOf(\"FIREPERF\")")
         buildConfigField("Boolean", "ENFORCE_DEFAULT_LOG_SRC", "Boolean.valueOf(false)")
         buildConfigField("String", "FIREPERF_VERSION_NAME", "String.valueOf(\"" + property("version") + "\")")
+        buildConfigField("Boolean", "ENFORCE_LEGACY_SESSIONS", "Boolean.valueOf(false)")
 
         if (project.hasProperty("fireperfBuildForAutopush")) {
             // This allows the SDK to be built for "Autopush" env when the mentioned flag
             // (-PfireperfBuildForAutopush) is passed in the gradle build command (of either the
             // SDK or the Test App).
             buildConfigField("String", "TRANSPORT_LOG_SRC", "String.valueOf(\"FIREPERF_AUTOPUSH\")")
             buildConfigField("Boolean", "ENFORCE_DEFAULT_LOG_SRC", "Boolean.valueOf(true)")
+            buildConfigField("Boolean", "ENFORCE_LEGACY_SESSIONS", "Boolean.valueOf(true)")
         }
 
         minSdkVersion project.minSdkVersion
@@ -124,7 +126,7 @@ dependencies {
     api("com.google.firebase:firebase-installations:18.0.0") {
         exclude group: 'com.google.firebase', module: 'firebase-common-ktx'
     }
-    api("com.google.firebase:firebase-sessions:2.0.7") {
+    api("com.google.firebase:firebase-sessions:3.0.0") {
         exclude group: 'com.google.firebase', module: 'firebase-common'
         exclude group: 'com.google.firebase', module: 'firebase-common-ktx'
         exclude group: 'com.google.firebase', module: 'firebase-components'

firebase-perf/src/main/java/com/google/firebase/perf/FirebasePerfEarly.java

@@ -21,7 +21,9 @@
 import com.google.firebase.perf.application.AppStateMonitor;
 import com.google.firebase.perf.config.ConfigResolver;
 import com.google.firebase.perf.metrics.AppStartTrace;
+import com.google.firebase.perf.session.FirebasePerformanceSessionSubscriber;
 import com.google.firebase.perf.session.SessionManager;
+import com.google.firebase.sessions.api.FirebaseSessionsDependencies;
 import java.util.concurrent.Executor;
 
 /**
@@ -34,29 +36,29 @@
 public class FirebasePerfEarly {
 
   public FirebasePerfEarly(
-      FirebaseApp app, @Nullable StartupTime startupTime, Executor uiExecutor) {
+      FirebaseApp app,
+      @Nullable StartupTime startupTime,
+      Executor uiExecutor,
+      SessionManager sessionManager) {
     Context context = app.getApplicationContext();
 
     // Initialize ConfigResolver early for accessing device caching layer.
     ConfigResolver configResolver = ConfigResolver.getInstance();
     configResolver.setApplicationContext(context);
 
-    AppStateMonitor appStateMonitor = AppStateMonitor.getInstance();
+    // Register FirebasePerformance as a subscriber ASAP - which will start collecting gauges if the
+    // FirebaseSession is verbose.
+    FirebaseSessionsDependencies.register(
+        new FirebasePerformanceSessionSubscriber(configResolver, sessionManager));
+
+    AppStateMonitor appStateMonitor = AppStateMonitor.getInstance(sessionManager);
     appStateMonitor.registerActivityLifecycleCallbacks(context);
     appStateMonitor.registerForAppColdStart(new FirebasePerformanceInitializer());
 
     if (startupTime != null) {
-      AppStartTrace appStartTrace = AppStartTrace.getInstance();
+      AppStartTrace appStartTrace = AppStartTrace.getInstance(sessionManager);
       appStartTrace.registerActivityLifecycleCallbacks(context);
       uiExecutor.execute(new AppStartTrace.StartFromBackgroundRunnable(appStartTrace));
     }
-
-    // TODO: Bring back Firebase Sessions dependency to watch for updates to sessions.
-
-    // In the case of cold start, we create a session and start collecting gauges as early as
-    // possible.
-    // There is code in SessionManager that prevents us from resetting the session twice in case
-    // of app cold start.
-    SessionManager.getInstance().initializeGaugeCollection();
   }
 }

firebase-perf/src/main/java/com/google/firebase/perf/FirebasePerfRegistrar.java

@@ -28,8 +28,13 @@
 import com.google.firebase.perf.injection.components.DaggerFirebasePerformanceComponent;
 import com.google.firebase.perf.injection.components.FirebasePerformanceComponent;
 import com.google.firebase.perf.injection.modules.FirebasePerformanceModule;
+import com.google.firebase.perf.session.PerfSession;
+import com.google.firebase.perf.session.SessionManager;
+import com.google.firebase.perf.session.gauges.GaugeManager;
 import com.google.firebase.platforminfo.LibraryVersionComponent;
 import com.google.firebase.remoteconfig.RemoteConfigComponent;
+import com.google.firebase.sessions.api.FirebaseSessionsDependencies;
+import com.google.firebase.sessions.api.SessionSubscriber;
 import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.Executor;
@@ -47,6 +52,11 @@ public class FirebasePerfRegistrar implements ComponentRegistrar {
   private static final String LIBRARY_NAME = "fire-perf";
   private static final String EARLY_LIBRARY_NAME = "fire-perf-early";
 
+  static {
+    // Add Firebase Performance as a dependency of Sessions when this class is loaded into memory.
+    FirebaseSessionsDependencies.addDependency(SessionSubscriber.Name.PERFORMANCE);
+  }
+
   @Override
   @Keep
   public List<Component<?>> getComponents() {
@@ -59,20 +69,28 @@ public List<Component<?>> getComponents() {
             .add(Dependency.required(FirebaseInstallationsApi.class))
             .add(Dependency.requiredProvider(TransportFactory.class))
             .add(Dependency.required(FirebasePerfEarly.class))
+            .add(Dependency.required(SessionManager.class))
             .factory(FirebasePerfRegistrar::providesFirebasePerformance)
             .build(),
         Component.builder(FirebasePerfEarly.class)
             .name(EARLY_LIBRARY_NAME)
             .add(Dependency.required(FirebaseApp.class))
             .add(Dependency.optionalProvider(StartupTime.class))
             .add(Dependency.required(uiExecutor))
+            .add(Dependency.required(SessionManager.class))
             .eagerInDefaultApp()
             .factory(
                 container ->
                     new FirebasePerfEarly(
                         container.get(FirebaseApp.class),
                         container.getProvider(StartupTime.class).get(),
-                        container.get(uiExecutor)))
+                        container.get(uiExecutor),
+                        container.get(SessionManager.class)))
+            .build(),
+        Component.builder(SessionManager.class)
+            .factory(
+                container ->
+                    new SessionManager(GaugeManager.getInstance(), PerfSession.createWithId(null)))
             .build(),
         /**
          * Fireperf SDK is lazily by {@link FirebasePerformanceInitializer} during {@link
@@ -94,7 +112,8 @@ private static FirebasePerformance providesFirebasePerformance(ComponentContaine
                     container.get(FirebaseApp.class),
                     container.get(FirebaseInstallationsApi.class),
                     container.getProvider(RemoteConfigComponent.class),
-                    container.getProvider(TransportFactory.class)))
+                    container.getProvider(TransportFactory.class),
+                    container.get(SessionManager.class)))
             .build();
 
     return component.getFirebasePerformance();

firebase-perf/src/main/java/com/google/firebase/perf/FirebasePerformance.java

@@ -34,6 +34,7 @@
 import com.google.firebase.perf.config.RemoteConfigManager;
 import com.google.firebase.perf.logging.AndroidLogger;
 import com.google.firebase.perf.logging.ConsoleUrlGenerator;
+import com.google.firebase.perf.logging.FirebaseSessionsEnforcementCheck;
 import com.google.firebase.perf.metrics.HttpMetric;
 import com.google.firebase.perf.metrics.Trace;
 import com.google.firebase.perf.session.SessionManager;
@@ -136,11 +137,6 @@ public static FirebasePerformance getInstance() {
   // to false if it's been force disabled or it is set to null if neither.
   @Nullable private Boolean mPerformanceCollectionForceEnabledState = null;
 
-  private final FirebaseApp firebaseApp;
-  private final Provider<RemoteConfigComponent> firebaseRemoteConfigProvider;
-  private final FirebaseInstallationsApi firebaseInstallationsApi;
-  private final Provider<TransportFactory> transportFactoryProvider;
-
   /**
    * Constructs the FirebasePerformance class and allows injecting dependencies.
    *
@@ -166,23 +162,19 @@ public static FirebasePerformance getInstance() {
       ConfigResolver configResolver,
       SessionManager sessionManager) {
 
-    this.firebaseApp = firebaseApp;
-    this.firebaseRemoteConfigProvider = firebaseRemoteConfigProvider;
-    this.firebaseInstallationsApi = firebaseInstallationsApi;
-    this.transportFactoryProvider = transportFactoryProvider;
-
     if (firebaseApp == null) {
       this.mPerformanceCollectionForceEnabledState = false;
       this.configResolver = configResolver;
       this.mMetadataBundle = new ImmutableBundle(new Bundle());
       return;
     }
+    FirebaseSessionsEnforcementCheck.setEnforcement(BuildConfig.ENFORCE_LEGACY_SESSIONS);
 
     TransportManager.getInstance()
-        .initialize(firebaseApp, firebaseInstallationsApi, transportFactoryProvider);
+        .initialize(
+            firebaseApp, firebaseInstallationsApi, transportFactoryProvider, sessionManager);
 
     Context appContext = firebaseApp.getApplicationContext();
-    // TODO(b/110178816): Explore moving off of main thread.
     mMetadataBundle = extractMetadata(appContext);
 
     remoteConfigManager.setFirebaseRemoteConfigProvider(firebaseRemoteConfigProvider);
@@ -192,6 +184,7 @@ public static FirebasePerformance getInstance() {
     sessionManager.setApplicationContext(appContext);
 
     mPerformanceCollectionForceEnabledState = configResolver.getIsPerformanceCollectionEnabled();
+
     if (logger.isLogcatEnabled() && isPerformanceCollectionEnabled()) {
       logger.info(
           String.format(
@@ -282,7 +275,7 @@ public synchronized void setPerformanceCollectionEnabled(@Nullable Boolean enabl
       return;
     }
 
-    if (configResolver.getIsPerformanceCollectionDeactivated()) {
+    if (Boolean.TRUE.equals(configResolver.getIsPerformanceCollectionDeactivated())) {
       logger.info("Firebase Performance is permanently disabled");
       return;
     }

firebase-perf/src/main/java/com/google/firebase/perf/application/AppStateMonitor.java

@@ -26,7 +26,9 @@
 import com.google.firebase.perf.logging.AndroidLogger;
 import com.google.firebase.perf.metrics.FrameMetricsCalculator.PerfFrameMetrics;
 import com.google.firebase.perf.metrics.Trace;
+import com.google.firebase.perf.session.PerfSession;
 import com.google.firebase.perf.session.SessionManager;
+import com.google.firebase.perf.session.gauges.GaugeManager;
 import com.google.firebase.perf.transport.TransportManager;
 import com.google.firebase.perf.util.Clock;
 import com.google.firebase.perf.util.Constants;
@@ -70,6 +72,7 @@ public class AppStateMonitor implements ActivityLifecycleCallbacks {
   private final TransportManager transportManager;
   private final ConfigResolver configResolver;
   private final Clock clock;
+  private final SessionManager sessionManager;
   private final boolean screenPerformanceRecordingSupported;
 
   private Timer resumeTime; // The time app comes to foreground
@@ -80,22 +83,46 @@ public class AppStateMonitor implements ActivityLifecycleCallbacks {
   private boolean isRegisteredForLifecycleCallbacks = false;
   private boolean isColdStart = true;
 
+  public static AppStateMonitor getInstance(SessionManager sessionManager) {
+    if (instance == null) {
+      synchronized (AppStateMonitor.class) {
+        if (instance == null) {
+          instance =
+              new AppStateMonitor(TransportManager.getInstance(), new Clock(), sessionManager);
+        }
+      }
+    }
+    return instance;
+  }
+
+  /**
+   * Returns the singleton instance, creating it with a default {@link SessionManager} if not
+   * already initialized. In production, {@link #getInstance(SessionManager)} is always called
+   * first by {@link com.google.firebase.perf.FirebasePerfEarly}, so the pre-seeded instance is
+   * returned. This overload exists for call sites that run after early initialization (e.g.
+   * {@link com.google.firebase.perf.application.AppStateUpdateHandler}) and for test environments.
+   */
   public static AppStateMonitor getInstance() {
     if (instance == null) {
       synchronized (AppStateMonitor.class) {
         if (instance == null) {
-          instance = new AppStateMonitor(TransportManager.getInstance(), new Clock());
+          instance =
+              new AppStateMonitor(
+                  TransportManager.getInstance(),
+                  new Clock(),
+                  new SessionManager(GaugeManager.getInstance(), PerfSession.createWithId(null)));
         }
       }
     }
     return instance;
   }
 
-  AppStateMonitor(TransportManager transportManager, Clock clock) {
+  AppStateMonitor(TransportManager transportManager, Clock clock, SessionManager sessionManager) {
     this(
         transportManager,
         clock,
         ConfigResolver.getInstance(),
+        sessionManager,
         isScreenPerformanceRecordingSupported());
   }
 
@@ -104,13 +131,24 @@ public static AppStateMonitor getInstance() {
       TransportManager transportManager,
       Clock clock,
       ConfigResolver configResolver,
+      SessionManager sessionManager,
       boolean screenPerformanceRecordingSupported) {
     this.transportManager = transportManager;
     this.clock = clock;
     this.configResolver = configResolver;
+    this.sessionManager = sessionManager;
     this.screenPerformanceRecordingSupported = screenPerformanceRecordingSupported;
   }
 
+  public SessionManager getSessionManager() {
+    return sessionManager;
+  }
+
+  @VisibleForTesting
+  public static void resetInstance() {
+    instance = null;
+  }
+
   public synchronized void registerActivityLifecycleCallbacks(Context context) {
     // Make sure the callback is registered only once.
     if (isRegisteredForLifecycleCallbacks) {
@@ -379,7 +417,7 @@ private void sendSessionLog(String name, Timer startTime, Timer endTime) {
             .setName(name)
             .setClientStartTimeUs(startTime.getMicros())
             .setDurationUs(startTime.getDurationMicros(endTime))
-            .addPerfSessions(SessionManager.getInstance().perfSession().build());
+            .addPerfSessions(sessionManager.perfSession().build());
     // Atomically get mTsnsCount and set it to zero.
     int tsnsCount = this.tsnsCount.getAndSet(0);
     synchronized (metricToCountMap) {

firebase-perf/src/main/java/com/google/firebase/perf/config/ConfigResolver.java

@@ -75,7 +75,7 @@ public ConfigResolver(
       @Nullable ImmutableBundle metadataBundle,
       @Nullable DeviceCacheManager deviceCacheManager) {
     this.remoteConfigManager =
-        remoteConfigManager == null ? RemoteConfigManager.getInstance() : remoteConfigManager;
+        remoteConfigManager == null ? new RemoteConfigManager() : remoteConfigManager;
     this.metadataBundle = metadataBundle == null ? new ImmutableBundle() : metadataBundle;
     this.deviceCacheManager =
         deviceCacheManager == null ? DeviceCacheManager.getInstance() : deviceCacheManager;
@@ -916,4 +916,8 @@ private boolean isGaugeCaptureFrequencyMsValid(long frequencyMilliseconds) {
   private boolean isSessionsMaxDurationMinutesValid(long maxDurationMin) {
     return maxDurationMin > 0;
   }
+
+  public RemoteConfigManager getRemoteConfigManager() {
+    return remoteConfigManager;
+  }
 }

firebase-perf/src/main/java/com/google/firebase/perf/config/RemoteConfigManager.java

@@ -47,7 +47,6 @@
 public class RemoteConfigManager {
 
   private static final AndroidLogger logger = AndroidLogger.getInstance();
-  private static final RemoteConfigManager instance = new RemoteConfigManager();
   private static final String FIREPERF_FRC_NAMESPACE_NAME = "fireperf";
   private static final long TIME_AFTER_WHICH_A_FETCH_IS_CONSIDERED_STALE_MS =
       TimeUnit.HOURS.toMillis(12);
@@ -67,7 +66,7 @@ public class RemoteConfigManager {
 
   // TODO(b/258263016): Migrate to go/firebase-android-executors
   @SuppressLint("ThreadPoolCreation")
-  private RemoteConfigManager() {
+  public RemoteConfigManager() {
     this(
         DeviceCacheManager.getInstance(),
         new ThreadPoolExecutor(
@@ -96,11 +95,6 @@ private RemoteConfigManager() {
     this.remoteConfigFetchDelayInMs = remoteConfigFetchDelayInMs;
   }
 
-  /** Gets the singleton instance. */
-  public static RemoteConfigManager getInstance() {
-    return instance;
-  }
-
   /**
    * Sets the {@link Provider} for {@link RemoteConfigComponent} from which we can extract the
    * {@link FirebaseRemoteConfig} instance whenever it gets available.

firebase-perf/src/main/java/com/google/firebase/perf/injection/modules/FirebasePerformanceModule.java

@@ -34,16 +34,19 @@ public class FirebasePerformanceModule {
   private final FirebaseInstallationsApi firebaseInstallations;
   private final Provider<RemoteConfigComponent> remoteConfigComponentProvider;
   private final Provider<TransportFactory> transportFactoryProvider;
+  private final SessionManager sessionManager;
 
   public FirebasePerformanceModule(
       @NonNull FirebaseApp firebaseApp,
       @NonNull FirebaseInstallationsApi firebaseInstallations,
       @NonNull Provider<RemoteConfigComponent> remoteConfigComponentProvider,
-      @NonNull Provider<TransportFactory> transportFactoryProvider) {
+      @NonNull Provider<TransportFactory> transportFactoryProvider,
+      @NonNull SessionManager sessionManager) {
     this.firebaseApp = firebaseApp;
     this.firebaseInstallations = firebaseInstallations;
     this.remoteConfigComponentProvider = remoteConfigComponentProvider;
     this.transportFactoryProvider = transportFactoryProvider;
+    this.sessionManager = sessionManager;
   }
 
   @Provides
@@ -68,7 +71,7 @@ Provider<TransportFactory> providesTransportFactoryProvider() {
 
   @Provides
   RemoteConfigManager providesRemoteConfigManager() {
-    return RemoteConfigManager.getInstance();
+    return ConfigResolver.getInstance().getRemoteConfigManager();
   }
 
   @Provides
@@ -78,6 +81,6 @@ ConfigResolver providesConfigResolver() {
 
   @Provides
   SessionManager providesSessionManager() {
-    return SessionManager.getInstance();
+    return sessionManager;
   }
 }