Migrate functions off of UI thread for continuations.

firebase-common/src/main/java/com/google/firebase/concurrent/ExecutorsRegistrar.java

@@ -37,7 +37,7 @@
 
 @SuppressLint("ThreadPoolCreation")
 public class ExecutorsRegistrar implements ComponentRegistrar {
-  private static final Lazy<ScheduledExecutorService> BG_EXECUTOR =
+  static final Lazy<ScheduledExecutorService> BG_EXECUTOR =
       new Lazy<>(
           () ->
               scheduled(
@@ -46,15 +46,15 @@ public class ExecutorsRegistrar implements ComponentRegistrar {
                       factory(
                           "Firebase Background", Process.THREAD_PRIORITY_BACKGROUND, bgPolicy()))));
 
-  private static final Lazy<ScheduledExecutorService> LITE_EXECUTOR =
+  static final Lazy<ScheduledExecutorService> LITE_EXECUTOR =
       new Lazy<>(
           () ->
               scheduled(
                   Executors.newFixedThreadPool(
                       Math.max(2, Runtime.getRuntime().availableProcessors()),
                       factory("Firebase Lite", Process.THREAD_PRIORITY_DEFAULT, litePolicy()))));
 
-  private static final Lazy<ScheduledExecutorService> BLOCKING_EXECUTOR =
+  static final Lazy<ScheduledExecutorService> BLOCKING_EXECUTOR =
       new Lazy<>(
           () ->
               scheduled(

firebase-functions/CHANGELOG.md

@@ -1,4 +1,5 @@
 # Unreleased
+* [changed] Avoid executing code on the UI thread as much as possible.
 
 # 20.2.1
 * [changed] Updated dependency of `firebase-iid` to its latest

firebase-functions/firebase-functions.gradle

@@ -50,6 +50,7 @@ android {
 }
 
 dependencies {
+    implementation project(':firebase-annotations')
     implementation project(':firebase-common')
     implementation project(':firebase-components')
     implementation project(':appcheck:firebase-appcheck-interop')
@@ -73,6 +74,7 @@ dependencies {
     javadocClasspath 'org.codehaus.mojo:animal-sniffer-annotations:1.19'
     javadocClasspath 'com.google.auto.value:auto-value-annotations:1.6.6'
 
+    androidTestImplementation project(":integ-testing")
     androidTestImplementation 'junit:junit:4.13.2'
     androidTestImplementation "com.google.truth:truth:$googleTruthVersion"
     androidTestImplementation 'androidx.test:runner:1.3.0'

firebase-functions/src/androidTest/java/com/google/firebase/functions/CallTest.java

@@ -21,10 +21,11 @@
 import static org.junit.Assert.assertTrue;
 
 import androidx.test.InstrumentationRegistry;
-import androidx.test.runner.AndroidJUnit4;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.gms.tasks.Task;
 import com.google.android.gms.tasks.Tasks;
 import com.google.firebase.FirebaseApp;
+import com.google.firebase.concurrent.TestOnlyExecutors;
 import com.google.firebase.functions.FirebaseFunctionsException.Code;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -91,7 +92,9 @@ public void testToken() throws InterruptedException, ExecutionException {
             () -> {
               HttpsCallableContext context = new HttpsCallableContext("token", null, null);
               return Tasks.forResult(context);
-            });
+            },
+            TestOnlyExecutors.lite(),
+            TestOnlyExecutors.ui());
 
     HttpsCallableReference function = functions.getHttpsCallable("tokenTest");
     Task<HttpsCallableResult> result = function.call(new HashMap<>());
@@ -112,7 +115,9 @@ public void testInstanceId() throws InterruptedException, ExecutionException {
             () -> {
               HttpsCallableContext context = new HttpsCallableContext(null, "iid", null);
               return Tasks.forResult(context);
-            });
+            },
+            TestOnlyExecutors.lite(),
+            TestOnlyExecutors.ui());
 
     HttpsCallableReference function = functions.getHttpsCallable("instanceIdTest");
     Task<HttpsCallableResult> result = function.call(new HashMap<>());
@@ -133,7 +138,9 @@ public void testAppCheck() throws InterruptedException, ExecutionException {
             () -> {
               HttpsCallableContext context = new HttpsCallableContext(null, null, "appCheck");
               return Tasks.forResult(context);
-            });
+            },
+            TestOnlyExecutors.lite(),
+            TestOnlyExecutors.ui());
 
     HttpsCallableReference function = functions.getHttpsCallable("appCheckTest");
     Task<HttpsCallableResult> result = function.call(new HashMap<>());

firebase-functions/src/androidTest/java/com/google/firebase/functions/FirebaseContextProviderTest.java

@@ -20,6 +20,7 @@
 import com.google.android.gms.tasks.Tasks;
 import com.google.firebase.appcheck.interop.InternalAppCheckTokenProvider;
 import com.google.firebase.auth.internal.InternalAuthProvider;
+import com.google.firebase.concurrent.TestOnlyExecutors;
 import com.google.firebase.iid.internal.FirebaseInstanceIdInternal;
 import com.google.firebase.inject.Deferred;
 import com.google.firebase.inject.Provider;
@@ -54,7 +55,10 @@ public void getContext_whenAuthAndAppCheckAreNotAvailable_shouldContainOnlyIid()
       throws ExecutionException, InterruptedException {
     FirebaseContextProvider contextProvider =
         new FirebaseContextProvider(
-            absentProvider(), providerOf(fixedIidProvider), absentDeferred());
+            absentProvider(),
+            providerOf(fixedIidProvider),
+            absentDeferred(),
+            TestOnlyExecutors.lite());
 
     HttpsCallableContext context = Tasks.await(contextProvider.getContext());
     assertThat(context.getAuthToken()).isNull();
@@ -67,7 +71,10 @@ public void getContext_whenOnlyAuthIsAvailable_shouldContainOnlyAuthTokenAndIid(
       throws ExecutionException, InterruptedException {
     FirebaseContextProvider contextProvider =
         new FirebaseContextProvider(
-            providerOf(fixedAuthProvider), providerOf(fixedIidProvider), absentDeferred());
+            providerOf(fixedAuthProvider),
+            providerOf(fixedIidProvider),
+            absentDeferred(),
+            TestOnlyExecutors.lite());
 
     HttpsCallableContext context = Tasks.await(contextProvider.getContext());
     assertThat(context.getAuthToken()).isEqualTo(AUTH_TOKEN);
@@ -80,7 +87,10 @@ public void getContext_whenOnlyAppCheckIsAvailable_shouldContainOnlyAppCheckToke
       throws ExecutionException, InterruptedException {
     FirebaseContextProvider contextProvider =
         new FirebaseContextProvider(
-            absentProvider(), providerOf(fixedIidProvider), deferredOf(fixedAppCheckProvider));
+            absentProvider(),
+            providerOf(fixedIidProvider),
+            deferredOf(fixedAppCheckProvider),
+            TestOnlyExecutors.lite());
 
     HttpsCallableContext context = Tasks.await(contextProvider.getContext());
     assertThat(context.getAuthToken()).isNull();
@@ -93,7 +103,10 @@ public void getContext_whenOnlyAuthIsAvailableAndNotSignedIn_shouldContainOnlyIi
       throws ExecutionException, InterruptedException {
     FirebaseContextProvider contextProvider =
         new FirebaseContextProvider(
-            providerOf(anonymousAuthProvider), providerOf(fixedIidProvider), absentDeferred());
+            providerOf(anonymousAuthProvider),
+            providerOf(fixedIidProvider),
+            absentDeferred(),
+            TestOnlyExecutors.lite());
 
     HttpsCallableContext context = Tasks.await(contextProvider.getContext());
     assertThat(context.getAuthToken()).isNull();
@@ -106,7 +119,10 @@ public void getContext_whenOnlyAppCheckIsAvailableAndHasError_shouldContainOnlyI
       throws ExecutionException, InterruptedException {
     FirebaseContextProvider contextProvider =
         new FirebaseContextProvider(
-            absentProvider(), providerOf(fixedIidProvider), deferredOf(errorAppCheckProvider));
+            absentProvider(),
+            providerOf(fixedIidProvider),
+            deferredOf(errorAppCheckProvider),
+            TestOnlyExecutors.lite());
 
     HttpsCallableContext context = Tasks.await(contextProvider.getContext());
     assertThat(context.getAuthToken()).isNull();
@@ -121,7 +137,8 @@ public void getContext_whenAuthAndAppCheckAreAvailable_shouldContainAuthAppCheck
         new FirebaseContextProvider(
             providerOf(fixedAuthProvider),
             providerOf(fixedIidProvider),
-            deferredOf(fixedAppCheckProvider));
+            deferredOf(fixedAppCheckProvider),
+            TestOnlyExecutors.lite());
 
     HttpsCallableContext context = Tasks.await(contextProvider.getContext());
     assertThat(context.getAuthToken()).isEqualTo(AUTH_TOKEN);

firebase-functions/src/main/java/com/google/firebase/functions/FirebaseContextProvider.java

@@ -17,12 +17,14 @@
 import android.util.Log;
 import com.google.android.gms.tasks.Task;
 import com.google.android.gms.tasks.Tasks;
+import com.google.firebase.annotations.concurrent.Lightweight;
 import com.google.firebase.appcheck.interop.InternalAppCheckTokenProvider;
 import com.google.firebase.auth.internal.InternalAuthProvider;
 import com.google.firebase.iid.internal.FirebaseInstanceIdInternal;
 import com.google.firebase.inject.Deferred;
 import com.google.firebase.inject.Provider;
 import com.google.firebase.internal.api.FirebaseNoSignedInUserException;
+import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicReference;
 
 /** A ContextProvider that uses FirebaseAuth to get the token. */
@@ -33,13 +35,16 @@ class FirebaseContextProvider implements ContextProvider {
   private final Provider<FirebaseInstanceIdInternal> instanceId;
   private final AtomicReference<InternalAppCheckTokenProvider> appCheckRef =
       new AtomicReference<>();
+  private final Executor executor;
 
   FirebaseContextProvider(
       Provider<InternalAuthProvider> tokenProvider,
       Provider<FirebaseInstanceIdInternal> instanceId,
-      Deferred<InternalAppCheckTokenProvider> appCheckDeferred) {
+      Deferred<InternalAppCheckTokenProvider> appCheckDeferred,
+      @Lightweight Executor executor) {
     this.tokenProvider = tokenProvider;
     this.instanceId = instanceId;
+    this.executor = executor;
     appCheckDeferred.whenAvailable(
         p -> {
           InternalAppCheckTokenProvider appCheck = p.get();
@@ -59,6 +64,7 @@ public Task<HttpsCallableContext> getContext() {
     Task<String> appCheckToken = getAppCheckToken();
     return Tasks.whenAll(authToken, appCheckToken)
         .onSuccessTask(
+            executor,
             v ->
                 Tasks.forResult(
                     new HttpsCallableContext(
@@ -74,6 +80,7 @@ private Task<String> getAuthToken() {
     }
     return auth.getAccessToken(false)
         .continueWith(
+            executor,
             task -> {
               String authToken = null;
               if (!task.isSuccessful()) {
@@ -98,6 +105,7 @@ private Task<String> getAppCheckToken() {
     return appCheck
         .getToken(false)
         .onSuccessTask(
+            executor,
             result -> {
               if (result.getError() != null) {
                 // If there was an error getting the App Check token, do NOT send the placeholder

firebase-functions/src/main/java/com/google/firebase/functions/FirebaseFunctions.java

@@ -15,7 +15,6 @@
 package com.google.firebase.functions;
 
 import android.content.Context;
-import android.os.Handler;
 import android.util.Log;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -27,6 +26,8 @@
 import com.google.android.gms.tasks.TaskCompletionSource;
 import com.google.android.gms.tasks.Tasks;
 import com.google.firebase.FirebaseApp;
+import com.google.firebase.annotations.concurrent.Lightweight;
+import com.google.firebase.annotations.concurrent.UiThread;
 import com.google.firebase.emulators.EmulatedServiceSettings;
 import com.google.firebase.functions.FirebaseFunctionsException.Code;
 import java.io.IOException;
@@ -35,6 +36,7 @@
 import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.Executor;
 import okhttp3.Call;
 import okhttp3.Callback;
 import okhttp3.MediaType;
@@ -69,6 +71,8 @@ public class FirebaseFunctions {
   // A provider of client metadata to include with calls.
   private final ContextProvider contextProvider;
 
+  private final Executor executor;
+
   // The projectId to use for all functions references.
   private final String projectId;
 
@@ -89,8 +93,11 @@ public class FirebaseFunctions {
       Context context,
       String projectId,
       String regionOrCustomDomain,
-      ContextProvider contextProvider) {
+      ContextProvider contextProvider,
+      @Lightweight Executor executor,
+      @UiThread Executor uiExecutor) {
     this.app = app;
+    this.executor = executor;
     this.client = new OkHttpClient();
     this.serializer = new Serializer();
     this.contextProvider = Preconditions.checkNotNull(contextProvider);
@@ -112,15 +119,16 @@ public class FirebaseFunctions {
       this.customDomain = regionOrCustomDomain;
     }
 
-    maybeInstallProviders(context);
+    maybeInstallProviders(context, uiExecutor);
   }
 
   /**
    * Runs ProviderInstaller.installIfNeededAsync once per application instance.
    *
    * @param context The application context.
+   * @param uiExecutor
    */
-  private static void maybeInstallProviders(Context context) {
+  private static void maybeInstallProviders(Context context, Executor uiExecutor) {
     // Make sure this only runs once.
     synchronized (providerInstalled) {
       if (providerInstallStarted) {
@@ -131,7 +139,7 @@ private static void maybeInstallProviders(Context context) {
 
     // Package installIfNeededAsync into a Runnable so it can be run on the main thread.
     // installIfNeededAsync checks to make sure it is on the main thread, and throws otherwise.
-    Runnable runnable =
+    uiExecutor.execute(
         () ->
             ProviderInstaller.installIfNeededAsync(
                 context,
@@ -146,10 +154,7 @@ public void onProviderInstallFailed(int i, android.content.Intent intent) {
                     Log.d("FirebaseFunctions", "Failed to update ssl context");
                     providerInstalled.setResult(null);
                   }
-                });
-
-    Handler handler = new Handler(context.getMainLooper());
-    handler.post(runnable);
+                }));
   }
 
   /**
@@ -269,8 +274,9 @@ public void useEmulator(@NonNull String host, int port) {
   Task<HttpsCallableResult> call(String name, @Nullable Object data, HttpsCallOptions options) {
     return providerInstalled
         .getTask()
-        .continueWithTask(task -> contextProvider.getContext())
+        .continueWithTask(executor, task -> contextProvider.getContext())
         .continueWithTask(
+            executor,
             task -> {
               if (!task.isSuccessful()) {
                 return Tasks.forException(task.getException());
@@ -291,8 +297,9 @@ Task<HttpsCallableResult> call(String name, @Nullable Object data, HttpsCallOpti
   Task<HttpsCallableResult> call(URL url, @Nullable Object data, HttpsCallOptions options) {
     return providerInstalled
         .getTask()
-        .continueWithTask(task -> contextProvider.getContext())
+        .continueWithTask(executor, task -> contextProvider.getContext())
         .continueWithTask(
+            executor,
             task -> {
               if (!task.isSuccessful()) {
                 return Tasks.forException(task.getException());
@@ -305,7 +312,7 @@ Task<HttpsCallableResult> call(URL url, @Nullable Object data, HttpsCallOptions
   /**
    * Calls a Callable HTTPS trigger endpoint.
    *
-   * @param name The name of the HTTPS trigger.
+   * @param url The name of the HTTPS trigger.
    * @param data Parameters to pass to the function. Can be anything encodable as JSON.
    * @param context Metadata to supply with the function call.
    * @return A Task that will be completed when the request is complete.

firebase-functions/src/main/java/com/google/firebase/functions/FunctionsMultiResourceComponent.java

@@ -16,9 +16,12 @@
 
 import android.content.Context;
 import androidx.annotation.GuardedBy;
+import androidx.annotation.UiThread;
 import com.google.firebase.FirebaseApp;
+import com.google.firebase.annotations.concurrent.Lightweight;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.Executor;
 
 /** Multi-resource container for Functions. */
 class FunctionsMultiResourceComponent {
@@ -33,12 +36,20 @@ class FunctionsMultiResourceComponent {
   private final Context applicationContext;
   private final ContextProvider contextProvider;
   private final FirebaseApp app;
+  private final Executor liteExecutor;
+  private final Executor uiExecutor;
 
   FunctionsMultiResourceComponent(
-      Context applicationContext, ContextProvider contextProvider, FirebaseApp app) {
+      Context applicationContext,
+      ContextProvider contextProvider,
+      FirebaseApp app,
+      @Lightweight Executor liteExecutor,
+      @UiThread Executor uiExecutor) {
     this.applicationContext = applicationContext;
     this.contextProvider = contextProvider;
     this.app = app;
+    this.liteExecutor = liteExecutor;
+    this.uiExecutor = uiExecutor;
   }
 
   synchronized FirebaseFunctions get(String regionOrCustomDomain) {
@@ -48,7 +59,13 @@ synchronized FirebaseFunctions get(String regionOrCustomDomain) {
     if (functions == null) {
       functions =
           new FirebaseFunctions(
-              app, applicationContext, projectId, regionOrCustomDomain, contextProvider);
+              app,
+              applicationContext,
+              projectId,
+              regionOrCustomDomain,
+              contextProvider,
+              liteExecutor,
+              uiExecutor);
       instances.put(regionOrCustomDomain, functions);
     }
     return functions;