Making Services closeable (#1196)

* Creating service contract

* Implementing close method

* Closing Services

* Closing services on rum shutdown

* Using getter val

* apiDump

* Update services/src/test/java/io/opentelemetry/android/internal/services/visiblescreen/VisibleScreenTrackerTest.java

Co-authored-by: jason plumb <[email protected]>

* Verifying services.close

* ApiDump

---------

Co-authored-by: jason plumb <[email protected]>

Author: LikeTheSalad

core/src/main/java/io/opentelemetry/android/OpenTelemetryRumBuilder.java

@@ -337,6 +337,7 @@ public OpenTelemetryRum build() {
                                     if (exportScheduleHandler != null) {
                                         exportScheduleHandler.disable();
                                     }
+                                    services.close();
                                 });
 
         // AsyncTask is deprecated but the thread pool is still used all over the Android SDK

services/api/services.api

@@ -1,10 +1,15 @@
-public class io/opentelemetry/android/internal/services/CacheStorage {
+public final class io/opentelemetry/android/internal/services/CacheStorage : io/opentelemetry/android/internal/services/Service {
 	public fun <init> (Landroid/content/Context;)V
-	public fun getCacheDir ()Ljava/io/File;
+	public final fun getCacheDir ()Ljava/io/File;
 }
 
-public final class io/opentelemetry/android/internal/services/Services {
+public abstract interface class io/opentelemetry/android/internal/services/Service : java/io/Closeable {
+	public fun close ()V
+}
+
+public final class io/opentelemetry/android/internal/services/Services : java/io/Closeable {
 	public static final field Companion Lio/opentelemetry/android/internal/services/Services$Companion;
+	public fun close ()V
 	public static final fun get (Landroid/app/Application;)Lio/opentelemetry/android/internal/services/Services;
 	public final fun getAppLifecycle ()Lio/opentelemetry/android/internal/services/applifecycle/AppLifecycle;
 	public final fun getCacheStorage ()Lio/opentelemetry/android/internal/services/CacheStorage;
@@ -19,7 +24,8 @@ public final class io/opentelemetry/android/internal/services/Services$Companion
 	public final fun set (Lio/opentelemetry/android/internal/services/Services;)V
 }
 
-public final class io/opentelemetry/android/internal/services/applifecycle/AppLifecycle {
+public final class io/opentelemetry/android/internal/services/applifecycle/AppLifecycle : io/opentelemetry/android/internal/services/Service {
+	public fun close ()V
 	public final fun registerListener (Lio/opentelemetry/android/internal/services/applifecycle/ApplicationStateListener;)V
 }
 
@@ -33,11 +39,12 @@ public class io/opentelemetry/android/internal/services/network/CarrierFinder {
 	public fun get ()Lio/opentelemetry/android/common/internal/features/networkattributes/data/Carrier;
 }
 
-public final class io/opentelemetry/android/internal/services/network/CurrentNetworkProvider {
+public final class io/opentelemetry/android/internal/services/network/CurrentNetworkProvider : io/opentelemetry/android/internal/services/Service {
 	public static final field NO_NETWORK Lio/opentelemetry/android/common/internal/features/networkattributes/data/CurrentNetwork;
 	public static final field UNKNOWN_NETWORK Lio/opentelemetry/android/common/internal/features/networkattributes/data/CurrentNetwork;
 	public fun <init> (Lio/opentelemetry/android/internal/services/network/detector/NetworkDetector;Landroid/net/ConnectivityManager;)V
 	public fun addNetworkChangeListener (Lio/opentelemetry/android/internal/services/network/NetworkChangeListener;)V
+	public fun close ()V
 	public fun getCurrentNetwork ()Lio/opentelemetry/android/common/internal/features/networkattributes/data/CurrentNetwork;
 	public fun refreshNetworkStatus ()Lio/opentelemetry/android/common/internal/features/networkattributes/data/CurrentNetwork;
 }
@@ -64,13 +71,15 @@ public abstract class io/opentelemetry/android/internal/services/periodicwork/Pe
 	public abstract fun shouldStopRunning ()Z
 }
 
-public final class io/opentelemetry/android/internal/services/periodicwork/PeriodicWork {
+public final class io/opentelemetry/android/internal/services/periodicwork/PeriodicWork : io/opentelemetry/android/internal/services/Service {
+	public fun close ()V
 	public final fun enqueue (Ljava/lang/Runnable;)V
 }
 
-public final class io/opentelemetry/android/internal/services/visiblescreen/VisibleScreenTracker {
+public final class io/opentelemetry/android/internal/services/visiblescreen/VisibleScreenTracker : io/opentelemetry/android/internal/services/Service {
 	public final fun activityPaused (Landroid/app/Activity;)V
 	public final fun activityResumed (Landroid/app/Activity;)V
+	public fun close ()V
 	public final fun fragmentPaused (Landroidx/fragment/app/Fragment;)V
 	public final fun fragmentResumed (Landroidx/fragment/app/Fragment;)V
 	public final fun getCurrentlyVisibleScreen ()Ljava/lang/String;

services/src/main/java/io/opentelemetry/android/internal/services/CacheStorage.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.android.internal.services
+
+import android.content.Context
+import java.io.File
+
+/**
+ * Utility to get information about the host app.
+ *
+ * This class is internal and not for public use. Its APIs are unstable and can change at any
+ * time.
+ */
+class CacheStorage(
+    private val appContext: Context,
+) : Service {
+    val cacheDir: File
+        get() = appContext.cacheDir
+}

services/src/main/java/io/opentelemetry/android/internal/services/CacheStorage.kt

@@ -0,0 +1,12 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.android.internal.services
+
+import java.io.Closeable
+
+interface Service : Closeable {
+    override fun close() {}
+}

services/src/main/java/io/opentelemetry/android/internal/services/Service.kt

@@ -15,13 +15,14 @@ import io.opentelemetry.android.internal.services.network.CurrentNetworkProvider
 import io.opentelemetry.android.internal.services.network.detector.NetworkDetector
 import io.opentelemetry.android.internal.services.periodicwork.PeriodicWork
 import io.opentelemetry.android.internal.services.visiblescreen.VisibleScreenTracker
+import java.io.Closeable
 
 /**
  * This class is internal and not for public use. Its APIs are unstable and can change at any time.
  */
 class Services internal constructor(
     private val factory: ServicesFactory,
-) {
+) : Closeable {
     val cacheStorage: CacheStorage by lazy {
         factory.createCacheStorage()
     }
@@ -42,6 +43,14 @@ class Services internal constructor(
         factory.createVisibleScreenTracker()
     }
 
+    override fun close() {
+        cacheStorage.close()
+        periodicWork.close()
+        currentNetworkProvider.close()
+        appLifecycle.close()
+        visibleScreenTracker.close()
+    }
+
     companion object {
         private var instance: Services? = null
 

services/src/main/java/io/opentelemetry/android/internal/services/Services.kt

@@ -6,19 +6,25 @@
 package io.opentelemetry.android.internal.services.applifecycle
 
 import androidx.lifecycle.Lifecycle
+import io.opentelemetry.android.internal.services.Service
 
 /**
  * This class is internal and not for public use. Its APIs are unstable and can change at any time.
  */
 class AppLifecycle internal constructor(
     private val applicationStateWatcher: ApplicationStateWatcher,
-    appLifecycle: Lifecycle,
-) {
+    private val appLifecycle: Lifecycle,
+) : Service {
     init {
         appLifecycle.addObserver(applicationStateWatcher)
     }
 
     fun registerListener(listener: ApplicationStateListener) {
         applicationStateWatcher.registerListener(listener)
     }
+
+    override fun close() {
+        appLifecycle.removeObserver(applicationStateWatcher)
+        applicationStateWatcher.close()
+    }
 }

services/src/main/java/io/opentelemetry/android/internal/services/applifecycle/AppLifecycle.kt

@@ -7,12 +7,15 @@ package io.opentelemetry.android.internal.services.applifecycle
 
 import androidx.lifecycle.DefaultLifecycleObserver
 import androidx.lifecycle.LifecycleOwner
+import java.io.Closeable
 import java.util.concurrent.CopyOnWriteArrayList
 
 /**
  * This class is internal and not for public use. Its APIs are unstable and can change at any time.
  */
-internal class ApplicationStateWatcher : DefaultLifecycleObserver {
+internal class ApplicationStateWatcher :
+    DefaultLifecycleObserver,
+    Closeable {
     private val applicationStateListeners: MutableList<ApplicationStateListener> =
         CopyOnWriteArrayList()
 
@@ -31,4 +34,8 @@ internal class ApplicationStateWatcher : DefaultLifecycleObserver {
     fun registerListener(listener: ApplicationStateListener) {
         applicationStateListeners.add(listener)
     }
+
+    override fun close() {
+        applicationStateListeners.clear()
+    }
 }

services/src/main/java/io/opentelemetry/android/internal/services/applifecycle/ApplicationStateWatcher.kt

@@ -16,9 +16,11 @@
 import io.opentelemetry.android.common.RumConstants;
 import io.opentelemetry.android.common.internal.features.networkattributes.data.CurrentNetwork;
 import io.opentelemetry.android.common.internal.features.networkattributes.data.NetworkState;
+import io.opentelemetry.android.internal.services.Service;
 import io.opentelemetry.android.internal.services.network.detector.NetworkDetector;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Supplier;
 
 // note: based on ideas from stack overflow:
@@ -31,7 +33,7 @@
  * <p>This class is internal and not for public use. Its APIs are unstable and can change at any
  * time.
  */
-public final class CurrentNetworkProvider {
+public final class CurrentNetworkProvider implements Service {
 
     public static final CurrentNetwork NO_NETWORK =
             CurrentNetwork.builder(NetworkState.NO_NETWORK_AVAILABLE).build();
@@ -42,6 +44,8 @@ public final class CurrentNetworkProvider {
     private final ConnectivityManager connectivityManager;
 
     private volatile CurrentNetwork currentNetwork = UNKNOWN_NETWORK;
+    private final AtomicReference<ConnectivityManager.NetworkCallback> callbackRef =
+            new AtomicReference<>();
     private final List<NetworkChangeListener> listeners = new CopyOnWriteArrayList<>();
 
     public CurrentNetworkProvider(
@@ -79,13 +83,17 @@ private void registerNetworkCallbacks(Supplier<NetworkRequest> createNetworkMoni
             registerNetworkCallbackApi24();
         } else {
             NetworkRequest networkRequest = createNetworkMonitoringRequest.get();
-            connectivityManager.registerNetworkCallback(networkRequest, new ConnectionMonitor());
+            ConnectivityManager.NetworkCallback callback = new ConnectionMonitor();
+            connectivityManager.registerNetworkCallback(networkRequest, callback);
+            callbackRef.set(callback);
         }
     }
 
     @RequiresApi(Build.VERSION_CODES.N)
     private void registerNetworkCallbackApi24() {
-        connectivityManager.registerDefaultNetworkCallback(new ConnectionMonitor());
+        ConnectivityManager.NetworkCallback callback = new ConnectionMonitor();
+        connectivityManager.registerDefaultNetworkCallback(callback);
+        callbackRef.set(callback);
     }
 
     /** Returns up-to-date {@linkplain CurrentNetwork current network information}. */
@@ -125,6 +133,16 @@ private void notifyListeners(CurrentNetwork activeNetwork) {
         }
     }
 
+    @Override
+    public void close() {
+        ConnectivityManager.NetworkCallback callback = callbackRef.get();
+        if (callback != null) {
+            connectivityManager.unregisterNetworkCallback(callback);
+            listeners.clear();
+            callbackRef.set(null);
+        }
+    }
+
     private final class ConnectionMonitor extends ConnectivityManager.NetworkCallback {
 
         @Override

services/src/main/java/io/opentelemetry/android/internal/services/network/CurrentNetworkProvider.java

@@ -7,18 +7,21 @@ package io.opentelemetry.android.internal.services.periodicwork
 
 import android.os.Handler
 import android.os.Looper
+import io.opentelemetry.android.internal.services.Service
+import java.io.Closeable
 import java.util.concurrent.ConcurrentLinkedQueue
 import java.util.concurrent.LinkedBlockingQueue
 import java.util.concurrent.ThreadPoolExecutor
 import java.util.concurrent.TimeUnit
+import java.util.concurrent.atomic.AtomicBoolean
 
 /**
  * Utility to run periodic background work.
  *
  * <p>This class is internal and not for public use. Its APIs are unstable and can change at any
  * time.
  */
-class PeriodicWork internal constructor() {
+class PeriodicWork internal constructor() : Service {
     private val delegator = WorkerDelegator()
 
     init {
@@ -29,14 +32,21 @@ class PeriodicWork internal constructor() {
         delegator.enqueue(runnable)
     }
 
-    private class WorkerDelegator : Runnable {
+    override fun close() {
+        delegator.close()
+    }
+
+    private class WorkerDelegator :
+        Runnable,
+        Closeable {
         companion object {
             private const val SECONDS_TO_KILL_IDLE_THREADS = 30L
             private const val SECONDS_FOR_NEXT_LOOP = 10L
             private const val MAX_AMOUNT_OF_WORKER_THREADS = 1
             private const val NUMBER_OF_PERMANENT_WORKER_THREADS = 0
         }
 
+        private val closed = AtomicBoolean(false)
         private val queue = ConcurrentLinkedQueue<Runnable>()
         private val handler = Handler(Looper.getMainLooper())
         private val executor =
@@ -49,14 +59,26 @@ class PeriodicWork internal constructor() {
             )
 
         fun enqueue(runnable: Runnable) {
+            if (closed.get()) {
+                return
+            }
             queue.add(runnable)
         }
 
         override fun run() {
+            if (closed.get()) {
+                return
+            }
             delegateToWorkerThread()
             scheduleNextLookUp()
         }
 
+        override fun close() {
+            if (!closed.compareAndSet(false, true)) {
+                queue.clear()
+            }
+        }
+
         private fun delegateToWorkerThread() {
             while (queue.isNotEmpty()) {
                 executor.execute(queue.poll())