From df36d878ce3f9c0a7a8e185d9b3b60b501e8cd1b Mon Sep 17 00:00:00 2001 From: Emmanuel Garcia Date: Fri, 14 Jan 2022 19:48:45 -0800 Subject: [PATCH 01/10] Teardown external view embedder prior to unmerging threads --- shell/common/rasterizer.cc | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/shell/common/rasterizer.cc b/shell/common/rasterizer.cc index 2fec73ab23793..71a922d05b456 100644 --- a/shell/common/rasterizer.cc +++ b/shell/common/rasterizer.cc @@ -91,16 +91,16 @@ void Rasterizer::Teardown() { surface_.reset(); last_layer_tree_.reset(); + if (external_view_embedder_) { + external_view_embedder_->Teardown(); + } + if (raster_thread_merger_.get() != nullptr && raster_thread_merger_.get()->IsMerged()) { FML_DCHECK(raster_thread_merger_->IsEnabled()); raster_thread_merger_->UnMergeNowIfLastOne(); raster_thread_merger_->SetMergeUnmergeCallback(nullptr); } - - if (external_view_embedder_) { - external_view_embedder_->Teardown(); - } } void Rasterizer::EnableThreadMergerIfNeeded() { From 087febfdb501a4da96f034a6ece1aeb1e6f9d7cc Mon Sep 17 00:00:00 2001 From: Emmanuel Garcia Date: Fri, 14 Jan 2022 20:26:05 -0800 Subject: [PATCH 02/10] Test --- flow/embedded_views.cc | 3 ++- flow/embedded_views.h | 3 ++- shell/common/rasterizer.cc | 4 ++-- .../external_view_embedder.cc | 7 +++++-- .../external_view_embedder.h | 3 ++- .../external_view_embedder_unittests.cc | 20 +++++++++++++++++-- 6 files changed, 31 insertions(+), 9 deletions(-) diff --git a/flow/embedded_views.cc b/flow/embedded_views.cc index c85ad66f8dc75..d76ad083ab6ec 100644 --- a/flow/embedded_views.cc +++ b/flow/embedded_views.cc @@ -64,6 +64,7 @@ bool ExternalViewEmbedder::SupportsDynamicThreadMerging() { return false; } -void ExternalViewEmbedder::Teardown() {} +void ExternalViewEmbedder::Teardown( + fml::RefPtr raster_thread_merger) {} } // namespace flutter diff --git a/flow/embedded_views.h b/flow/embedded_views.h index f62e4e86fe443..07d1028428c1c 100644 --- a/flow/embedded_views.h +++ b/flow/embedded_views.h @@ -333,7 +333,8 @@ class ExternalViewEmbedder { // Called when the rasterizer is being torn down. // This method provides a way to release resources associated with the current // embedder. - virtual void Teardown(); + virtual void Teardown( + fml::RefPtr raster_thread_merger); FML_DISALLOW_COPY_AND_ASSIGN(ExternalViewEmbedder); diff --git a/shell/common/rasterizer.cc b/shell/common/rasterizer.cc index 71a922d05b456..c4a060772bfea 100644 --- a/shell/common/rasterizer.cc +++ b/shell/common/rasterizer.cc @@ -91,8 +91,8 @@ void Rasterizer::Teardown() { surface_.reset(); last_layer_tree_.reset(); - if (external_view_embedder_) { - external_view_embedder_->Teardown(); + if (external_view_embedder_ && raster_thread_merger_.get() != nullptr) { + external_view_embedder_->Teardown(raster_thread_merger_); } if (raster_thread_merger_.get() != nullptr && diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.cc b/shell/platform/android/external_view_embedder/external_view_embedder.cc index 0c326eb950b03..08fb7287f496d 100644 --- a/shell/platform/android/external_view_embedder/external_view_embedder.cc +++ b/shell/platform/android/external_view_embedder/external_view_embedder.cc @@ -299,8 +299,11 @@ bool AndroidExternalViewEmbedder::SupportsDynamicThreadMerging() { } // |ExternalViewEmbedder| -void AndroidExternalViewEmbedder::Teardown() { - surface_pool_->DestroyLayers(jni_facade_); +void AndroidExternalViewEmbedder::Teardown( + fml::RefPtr raster_thread_merger) { + if (raster_thread_merger->IsOnPlatformThread()) { + surface_pool_->DestroyLayers(jni_facade_); + } } } // namespace flutter diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.h b/shell/platform/android/external_view_embedder/external_view_embedder.h index 278d7693e7661..e98bcd5049a33 100644 --- a/shell/platform/android/external_view_embedder/external_view_embedder.h +++ b/shell/platform/android/external_view_embedder/external_view_embedder.h @@ -73,7 +73,8 @@ class AndroidExternalViewEmbedder final : public ExternalViewEmbedder { bool SupportsDynamicThreadMerging() override; - void Teardown() override; + void Teardown( + fml::RefPtr raster_thread_merger) override; // Gets the rect based on the device pixel ratio of a platform view displayed // on the screen. diff --git a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc index c5a3c19701a3f..ca9518efe3238 100644 --- a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc +++ b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc @@ -953,9 +953,25 @@ TEST(AndroidExternalViewEmbedder, Teardown) { embedder->EndFrame(/*should_resubmit_frame=*/false, raster_thread_merger); + // Teardown while on platform thread. + ASSERT_TRUE(raster_thread_merger->IsOnPlatformThread()); EXPECT_CALL(*jni_mock, FlutterViewDestroyOverlaySurfaces()); - // Teardown. - embedder->Teardown(); + embedder->Teardown(raster_thread_merger); + + // Teardown while on raster thread. + { + fml::Thread raster_thread("raster"); + auto raster_thread_merger = fml::MakeRefCounted( + raster_thread.GetTaskRunner() + ->GetTaskQueueId(), // Make the platform thread be the raster + // thread. + raster_thread.GetTaskRunner()->GetTaskQueueId()); + + ASSERT_FALSE(raster_thread_merger->IsOnPlatformThread()); + + EXPECT_CALL(*jni_mock, FlutterViewDestroyOverlaySurfaces()).Times(0); + embedder->Teardown(raster_thread_merger); + } } } // namespace testing From 15314aef1bb5e5af8ef23d272b71c94fd922e632 Mon Sep 17 00:00:00 2001 From: Emmanuel Garcia Date: Tue, 18 Jan 2022 13:34:50 -0800 Subject: [PATCH 03/10] Allow DestroyLayers to be called from any thread --- flow/embedded_views.cc | 3 +- flow/embedded_views.h | 3 +- shell/common/rasterizer.cc | 8 ++-- .../external_view_embedder.cc | 9 ++-- .../external_view_embedder.h | 3 +- .../external_view_embedder_unittests.cc | 20 +-------- .../flutter/embedding/engine/FlutterJNI.java | 41 ++++++++++++++++--- .../embedding/engine/FlutterJNITest.java | 37 +++++++++++++++++ 8 files changed, 84 insertions(+), 40 deletions(-) diff --git a/flow/embedded_views.cc b/flow/embedded_views.cc index d76ad083ab6ec..c85ad66f8dc75 100644 --- a/flow/embedded_views.cc +++ b/flow/embedded_views.cc @@ -64,7 +64,6 @@ bool ExternalViewEmbedder::SupportsDynamicThreadMerging() { return false; } -void ExternalViewEmbedder::Teardown( - fml::RefPtr raster_thread_merger) {} +void ExternalViewEmbedder::Teardown() {} } // namespace flutter diff --git a/flow/embedded_views.h b/flow/embedded_views.h index 07d1028428c1c..f62e4e86fe443 100644 --- a/flow/embedded_views.h +++ b/flow/embedded_views.h @@ -333,8 +333,7 @@ class ExternalViewEmbedder { // Called when the rasterizer is being torn down. // This method provides a way to release resources associated with the current // embedder. - virtual void Teardown( - fml::RefPtr raster_thread_merger); + virtual void Teardown(); FML_DISALLOW_COPY_AND_ASSIGN(ExternalViewEmbedder); diff --git a/shell/common/rasterizer.cc b/shell/common/rasterizer.cc index c4a060772bfea..2fec73ab23793 100644 --- a/shell/common/rasterizer.cc +++ b/shell/common/rasterizer.cc @@ -91,16 +91,16 @@ void Rasterizer::Teardown() { surface_.reset(); last_layer_tree_.reset(); - if (external_view_embedder_ && raster_thread_merger_.get() != nullptr) { - external_view_embedder_->Teardown(raster_thread_merger_); - } - if (raster_thread_merger_.get() != nullptr && raster_thread_merger_.get()->IsMerged()) { FML_DCHECK(raster_thread_merger_->IsEnabled()); raster_thread_merger_->UnMergeNowIfLastOne(); raster_thread_merger_->SetMergeUnmergeCallback(nullptr); } + + if (external_view_embedder_) { + external_view_embedder_->Teardown(); + } } void Rasterizer::EnableThreadMergerIfNeeded() { diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.cc b/shell/platform/android/external_view_embedder/external_view_embedder.cc index 08fb7287f496d..159f2ff128e06 100644 --- a/shell/platform/android/external_view_embedder/external_view_embedder.cc +++ b/shell/platform/android/external_view_embedder/external_view_embedder.cc @@ -264,7 +264,7 @@ void AndroidExternalViewEmbedder::BeginFrame( // The surface size changed. Therefore, destroy existing surfaces as // the existing surfaces in the pool can't be recycled. - if (frame_size_ != frame_size && raster_thread_merger->IsOnPlatformThread()) { + if (frame_size_ != frame_size) { surface_pool_->DestroyLayers(jni_facade_); } surface_pool_->SetFrameSize(frame_size); @@ -299,11 +299,8 @@ bool AndroidExternalViewEmbedder::SupportsDynamicThreadMerging() { } // |ExternalViewEmbedder| -void AndroidExternalViewEmbedder::Teardown( - fml::RefPtr raster_thread_merger) { - if (raster_thread_merger->IsOnPlatformThread()) { - surface_pool_->DestroyLayers(jni_facade_); - } +void AndroidExternalViewEmbedder::Teardown() { + surface_pool_->DestroyLayers(jni_facade_); } } // namespace flutter diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.h b/shell/platform/android/external_view_embedder/external_view_embedder.h index e98bcd5049a33..278d7693e7661 100644 --- a/shell/platform/android/external_view_embedder/external_view_embedder.h +++ b/shell/platform/android/external_view_embedder/external_view_embedder.h @@ -73,8 +73,7 @@ class AndroidExternalViewEmbedder final : public ExternalViewEmbedder { bool SupportsDynamicThreadMerging() override; - void Teardown( - fml::RefPtr raster_thread_merger) override; + void Teardown() override; // Gets the rect based on the device pixel ratio of a platform view displayed // on the screen. diff --git a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc index ca9518efe3238..c5a3c19701a3f 100644 --- a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc +++ b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc @@ -953,25 +953,9 @@ TEST(AndroidExternalViewEmbedder, Teardown) { embedder->EndFrame(/*should_resubmit_frame=*/false, raster_thread_merger); - // Teardown while on platform thread. - ASSERT_TRUE(raster_thread_merger->IsOnPlatformThread()); EXPECT_CALL(*jni_mock, FlutterViewDestroyOverlaySurfaces()); - embedder->Teardown(raster_thread_merger); - - // Teardown while on raster thread. - { - fml::Thread raster_thread("raster"); - auto raster_thread_merger = fml::MakeRefCounted( - raster_thread.GetTaskRunner() - ->GetTaskQueueId(), // Make the platform thread be the raster - // thread. - raster_thread.GetTaskRunner()->GetTaskQueueId()); - - ASSERT_FALSE(raster_thread_merger->IsOnPlatformThread()); - - EXPECT_CALL(*jni_mock, FlutterViewDestroyOverlaySurfaces()).Times(0); - embedder->Teardown(raster_thread_merger); - } + // Teardown. + embedder->Teardown(); } } // namespace testing diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java index 128eb5c6a8e8d..e3a4de6c6f16e 100644 --- a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java +++ b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java @@ -11,6 +11,7 @@ import android.graphics.ImageDecoder; import android.graphics.SurfaceTexture; import android.os.Build; +import android.os.Handler; import android.os.Looper; import android.util.Size; import android.view.Surface; @@ -1171,12 +1172,25 @@ public FlutterOverlaySurface createOverlaySurface() { @SuppressWarnings("unused") @UiThread public void destroyOverlaySurfaces() { - ensureRunningOnMainThread(); - if (platformViewsController == null) { - throw new RuntimeException( - "platformViewsController must be set before attempting to destroy an overlay surface"); - } - platformViewsController.destroyOverlaySurfaces(); + // Normally, this method is called on the Android main thread. + // + // However, it may be called from a different thread after the thread merger lease expired + // and the rasterizer is being torn down. + // + // The platform view embedder may keep these surfaces even after the lease have expired in + // case they are used in a future frame that contains platform views. + // + // This is particularly an issue when a "cached" engine is used. + // + // See Rasterizer::Teardown in C++, and FlutterEngineCache in Java. + runOnMainThread( + () -> { + if (platformViewsController == null) { + throw new RuntimeException( + "platformViewsController must be set before attempting to destroy an overlay surface"); + } + platformViewsController.destroyOverlaySurfaces(); + }); } // ----- End Engine Lifecycle Support ---- @@ -1406,6 +1420,21 @@ private void ensureRunningOnMainThread() { } } + /** + * Causes the runnable r to be run on the Android main thread. If the current thread is different, + * then it adds the runnable to the message queue of the main thread. + * + * @param r The runnable that will be executed. + */ + private void runOnMainThread(Runnable r) { + if (Looper.myLooper() == mainLooper) { + r.run(); + return; + } + final Handler handler = new Handler(mainLooper); + handler.post(r); + } + /** * Delegate responsible for creating and updating Android-side caches of Flutter's semantics tree * and custom accessibility actions. diff --git a/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java b/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java index 5f057c36609a0..7e9455387c4ac 100644 --- a/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java +++ b/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java @@ -1,10 +1,13 @@ package io.flutter.embedding.engine; +import static android.os.Looper.getMainLooper; import static org.junit.Assert.assertEquals; +import static org.junit.Assert.fail; import static org.mockito.Mockito.mock; import static org.mockito.Mockito.times; import static org.mockito.Mockito.verify; import static org.mockito.Mockito.when; +import static org.robolectric.Shadows.shadowOf; import android.annotation.TargetApi; import android.content.Context; @@ -19,7 +22,9 @@ import io.flutter.plugin.platform.PlatformViewsController; import java.nio.ByteBuffer; import java.util.Locale; +import java.util.concurrent.CountDownLatch; import java.util.concurrent.atomic.AtomicInteger; +import java.util.concurrent.atomic.AtomicReference; import org.junit.Test; import org.junit.runner.RunWith; import org.robolectric.RobolectricTestRunner; @@ -245,4 +250,36 @@ public void invokePlatformMessageResponseCallback__wantsDirectBuffer() { ByteBuffer buffer = ByteBuffer.allocate(4); flutterJNI.invokePlatformMessageResponseCallback(0, buffer, buffer.position()); } + + @Test + public void destroyOverlaySurfaces__calledFromDifferentThread() throws Exception { + PlatformViewsController platformViewsController = mock(PlatformViewsController.class); + + FlutterJNI flutterJNI = new FlutterJNI(); + flutterJNI.setPlatformViewsController(platformViewsController); + + AtomicReference exception = new AtomicReference<>(); + + // --- Execute Test --- + CountDownLatch latch = new CountDownLatch(1); + Thread thread = + new Thread( + () -> { + try { + flutterJNI.destroyOverlaySurfaces(); + } catch (Exception e) { + exception.set(e); + } + latch.countDown(); + }); + + thread.start(); + latch.await(); + shadowOf(getMainLooper()).idle(); + + // --- Verify Results --- + if (exception.get() != null) { + fail("Unexpected exception: " + exception.get().toString()); + } + } } From dd7b46253534a23bbeaec671cb2047c2089d0eaf Mon Sep 17 00:00:00 2001 From: Emmanuel Garcia Date: Tue, 18 Jan 2022 15:59:08 -0800 Subject: [PATCH 04/10] Clarify a bit more --- .../android/io/flutter/embedding/engine/FlutterJNI.java | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java index e3a4de6c6f16e..a5d4a12f125ad 100644 --- a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java +++ b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java @@ -1180,7 +1180,9 @@ public void destroyOverlaySurfaces() { // The platform view embedder may keep these surfaces even after the lease have expired in // case they are used in a future frame that contains platform views. // - // This is particularly an issue when a "cached" engine is used. + // This is particularly an issue when a "cached" engine is used. In this case, this method + // would not be called if it requires to run on the main thread. For this reason, this + // method hops to the Android main thread if necessary. // // See Rasterizer::Teardown in C++, and FlutterEngineCache in Java. runOnMainThread( From a4e4e7823411040fd88d82e175997e77636a2947 Mon Sep 17 00:00:00 2001 From: Emmanuel Garcia Date: Tue, 18 Jan 2022 18:12:44 -0800 Subject: [PATCH 05/10] Fix test --- .../external_view_embedder_unittests.cc | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc index c5a3c19701a3f..0f7043b41993a 100644 --- a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc +++ b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc @@ -843,9 +843,7 @@ TEST(AndroidExternalViewEmbedder, DoesNotDestroyOverlayLayersOnSizeChange) { embedder->EndFrame(/*should_resubmit_frame=*/false, raster_thread_merger); } - // Changing the frame size from the raster thread does not make JNI calls. - - EXPECT_CALL(*jni_mock, FlutterViewDestroyOverlaySurfaces()).Times(0); + EXPECT_CALL(*jni_mock, FlutterViewDestroyOverlaySurfaces()).Times(1); EXPECT_CALL(*jni_mock, FlutterViewBeginFrame()).Times(0); fml::Thread platform_thread("platform"); From 20250bca6113eb5790bd02a5d52a28dc9feeeed2 Mon Sep 17 00:00:00 2001 From: Emmanuel Garcia Date: Wed, 19 Jan 2022 19:47:30 -0800 Subject: [PATCH 06/10] Add lock --- .../flutter/embedding/engine/FlutterJNI.java | 54 +++++++++++++----- .../embedding/engine/FlutterJNITest.java | 57 +++++++++++-------- 2 files changed, 73 insertions(+), 38 deletions(-) diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java index a5d4a12f125ad..6d16ad31f84b6 100644 --- a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java +++ b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java @@ -42,6 +42,7 @@ import java.util.Locale; import java.util.Set; import java.util.concurrent.CopyOnWriteArraySet; +import java.util.concurrent.atomic.AtomicReference; import java.util.concurrent.locks.ReentrantReadWriteLock; /** @@ -73,7 +74,7 @@ * * 
{@code
  * // Instantiate FlutterJNI and attach to the native side.
- * FlutterJNI flutterJNI = new FlutterJNI();
+ * FlutterJNI flutterJNI = new FlutterJNI(Looper.getMainLooper());
  * flutterJNI.attachToNative();
  *
  * // Use FlutterJNI as desired. flutterJNI.dispatchPointerDataPacket(...);
@@ -107,11 +108,13 @@ public class FlutterJNI {
   // platform thread and doesn't require locking.
   private ReentrantReadWriteLock shellHolderLock = new ReentrantReadWriteLock();
 
-  // Prefer using the FlutterJNI.Factory so it's easier to test.
+  /** @param looper The main looper. Typically, Looper.getMainLooper(). */
+  public FlutterJNI(@NonNull Looper looper) {
+    mainLooper = looper;
+  }
+
   public FlutterJNI() {
-    // We cache the main looper so that we can ensure calls are made on the main thread
-    // without consistently paying the synchronization cost of getMainLooper().
-    mainLooper = Looper.getMainLooper();
+    this(Looper.getMainLooper());
   }
 
   /**
@@ -1170,8 +1173,7 @@ public FlutterOverlaySurface createOverlaySurface() {
   }
 
   @SuppressWarnings("unused")
-  @UiThread
-  public void destroyOverlaySurfaces() {
+  public void destroyOverlaySurfaces() throws Exception {
     // Normally, this method is called on the Android main thread.
     //
     // However, it may be called from a different thread after the thread merger lease expired
@@ -1185,14 +1187,15 @@ public void destroyOverlaySurfaces() {
     // method hops to the Android main thread if necessary.
     //
     // See Rasterizer::Teardown in C++, and FlutterEngineCache in Java.
-    runOnMainThread(
+    runOnLooper(
         () -> {
           if (platformViewsController == null) {
             throw new RuntimeException(
                 "platformViewsController must be set before attempting to destroy an overlay surface");
           }
           platformViewsController.destroyOverlaySurfaces();
-        });
+        },
+        mainLooper);
   }
   // ----- End Engine Lifecycle Support ----
 
@@ -1423,18 +1426,39 @@ private void ensureRunningOnMainThread() {
   }
 
   /**
-   * Causes the runnable r to be run on the Android main thread. If the current thread is different,
-   * then it adds the runnable to the message queue of the main thread.
+   * Causes the runnable r to be run on the thread associated with the given looper l. Then, it
+   * waits for the runnable to run.
+   *
+   * 
If the runnable throws, then the exception is captured and rethrown in the current thread.
    *
    * @param r The runnable that will be executed.
+   * @param l The looper where the runnable is added.
    */
-  private void runOnMainThread(Runnable r) {
-    if (Looper.myLooper() == mainLooper) {
+  private void runOnLooper(Runnable r, Looper l) throws Exception {
+    if (Looper.myLooper() == l) {
       r.run();
       return;
     }
-    final Handler handler = new Handler(mainLooper);
-    handler.post(r);
+    final AtomicReference exception = new AtomicReference<>();
+    final Handler handler = new Handler(l);
+    handler.post(
+        () -> {
+          try {
+            r.run();
+          } catch (Exception e) {
+            exception.set(e);
+          }
+          synchronized (handler) {
+            handler.notify();
+          }
+        });
+    synchronized (handler) {
+      handler.wait();
+    }
+    if (exception.get() != null) {
+      // Rethrow the exception on the current thread.
+      throw exception.get();
+    }
   }
 
   /**
diff --git a/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java b/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
index 7e9455387c4ac..22f09c7ae286d 100644
--- a/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
+++ b/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
@@ -1,19 +1,19 @@
 package io.flutter.embedding.engine;
 
-import static android.os.Looper.getMainLooper;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
-import static org.robolectric.Shadows.shadowOf;
 
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.content.res.Configuration;
 import android.content.res.Resources;
+import android.os.Handler;
 import android.os.LocaleList;
+import android.os.Looper;
+import android.os.Message;
 import io.flutter.embedding.engine.dart.DartExecutor;
 import io.flutter.embedding.engine.mutatorsstack.FlutterMutatorsStack;
 import io.flutter.embedding.engine.renderer.FlutterUiDisplayListener;
@@ -22,7 +22,6 @@
 import io.flutter.plugin.platform.PlatformViewsController;
 import java.nio.ByteBuffer;
 import java.util.Locale;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 import org.junit.Test;
@@ -253,33 +252,45 @@ public void invokePlatformMessageResponseCallback__wantsDirectBuffer() {
 
   @Test
   public void destroyOverlaySurfaces__calledFromDifferentThread() throws Exception {
+    AtomicReference flutterJNI = new AtomicReference<>();
     PlatformViewsController platformViewsController = mock(PlatformViewsController.class);
 
-    FlutterJNI flutterJNI = new FlutterJNI();
-    flutterJNI.setPlatformViewsController(platformViewsController);
-
-    AtomicReference exception = new AtomicReference<>();
-
-    // --- Execute Test ---
-    CountDownLatch latch = new CountDownLatch(1);
-    Thread thread =
+    Object lock = new Object();
+    // This thread acts as the Android main thread.
+    // This is required because the test itself runs on the main thread, and without this
+    // workaround,
+    // a deadlock is produced.
+    Thread mainThreadImpostor =
         new Thread(
             () -> {
-              try {
-                flutterJNI.destroyOverlaySurfaces();
-              } catch (Exception e) {
-                exception.set(e);
+              Looper.prepare();
+
+              flutterJNI.set(new FlutterJNI(Looper.myLooper()));
+              flutterJNI.get().setPlatformViewsController(platformViewsController);
+
+              synchronized (lock) {
+                lock.notify();
               }
-              latch.countDown();
+
+              new Handler(Looper.myLooper()) {
+                public void handleMessage(Message msg) {
+                  msg.getCallback().run();
+                }
+              };
+              Looper.loop();
             });
 
-    thread.start();
-    latch.await();
-    shadowOf(getMainLooper()).idle();
+    mainThreadImpostor.start();
+    synchronized (lock) {
+      lock.wait();
+    }
+
+    // --- Execute Test ---
+    flutterJNI.get().destroyOverlaySurfaces();
 
     // --- Verify Results ---
-    if (exception.get() != null) {
-      fail("Unexpected exception: " + exception.get().toString());
-    }
+    verify(platformViewsController, times(1)).destroyOverlaySurfaces();
+
+    mainThreadImpostor.interrupt();
   }
 }

From 6371bb0c2d2968a039636c73822ec27cdd918f78 Mon Sep 17 00:00:00 2001
From: Emmanuel Garcia 
Date: Wed, 19 Jan 2022 20:02:17 -0800
Subject: [PATCH 07/10] Format

---
 .../test/io/flutter/embedding/engine/FlutterJNITest.java       | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java b/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
index 22f09c7ae286d..dbfd45f26e200 100644
--- a/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
+++ b/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
@@ -258,8 +258,7 @@ public void destroyOverlaySurfaces__calledFromDifferentThread() throws Exception
     Object lock = new Object();
     // This thread acts as the Android main thread.
     // This is required because the test itself runs on the main thread, and without this
-    // workaround,
-    // a deadlock is produced.
+    // workaround, a deadlock is produced.
     Thread mainThreadImpostor =
         new Thread(
             () -> {

From 9c579533e6ee2cd2a4c9721757c7babd39bb7eec Mon Sep 17 00:00:00 2001
From: Emmanuel Garcia 
Date: Fri, 21 Jan 2022 16:15:09 -0800
Subject: [PATCH 08/10] Reuse C++ API

---
 .../external_view_embedder.cc                 | 23 +++++-
 .../external_view_embedder.h                  | 12 ++-
 .../external_view_embedder_unittests.cc       | 46 +++++++----
 .../flutter/embedding/engine/FlutterJNI.java  | 81 +++----------------
 .../platform/android/platform_view_android.cc | 10 +--
 .../embedding/engine/FlutterJNITest.java      | 47 -----------
 tools/android_lint/project.xml                |  4 +-
 7 files changed, 79 insertions(+), 144 deletions(-)

diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.cc b/shell/platform/android/external_view_embedder/external_view_embedder.cc
index 159f2ff128e06..84f2ab9378125 100644
--- a/shell/platform/android/external_view_embedder/external_view_embedder.cc
+++ b/shell/platform/android/external_view_embedder/external_view_embedder.cc
@@ -4,6 +4,8 @@
 
 #include "flutter/shell/platform/android/external_view_embedder/external_view_embedder.h"
 
+#include "flutter/fml/synchronization/waitable_event.h"
+#include "flutter/fml/task_runner.h"
 #include "flutter/fml/trace_event.h"
 #include "flutter/shell/platform/android/surface/android_surface.h"
 
@@ -12,12 +14,14 @@ namespace flutter {
 AndroidExternalViewEmbedder::AndroidExternalViewEmbedder(
     const AndroidContext& android_context,
     std::shared_ptr jni_facade,
-    std::shared_ptr surface_factory)
+    std::shared_ptr surface_factory,
+    TaskRunners task_runners)
     : ExternalViewEmbedder(),
       android_context_(android_context),
       jni_facade_(jni_facade),
       surface_factory_(surface_factory),
-      surface_pool_(std::make_unique()) {}
+      surface_pool_(std::make_unique()),
+      task_runners_(task_runners) {}
 
 // |ExternalViewEmbedder|
 void AndroidExternalViewEmbedder::PrerollCompositeEmbeddedView(
@@ -265,7 +269,7 @@ void AndroidExternalViewEmbedder::BeginFrame(
   // The surface size changed. Therefore, destroy existing surfaces as
   // the existing surfaces in the pool can't be recycled.
   if (frame_size_ != frame_size) {
-    surface_pool_->DestroyLayers(jni_facade_);
+    DestroySurfaces();
   }
   surface_pool_->SetFrameSize(frame_size);
   // JNI method must be called on the platform thread.
@@ -300,7 +304,18 @@ bool AndroidExternalViewEmbedder::SupportsDynamicThreadMerging() {
 
 // |ExternalViewEmbedder|
 void AndroidExternalViewEmbedder::Teardown() {
-  surface_pool_->DestroyLayers(jni_facade_);
+  DestroySurfaces();
+}
+
+// |ExternalViewEmbedder|
+void AndroidExternalViewEmbedder::DestroySurfaces() {
+  fml::AutoResetWaitableEvent latch;
+  fml::TaskRunner::RunNowOrPostTask(task_runners_.GetPlatformTaskRunner(),
+                                    [&]() {
+                                      surface_pool_->DestroyLayers(jni_facade_);
+                                      latch.Signal();
+                                    });
+  latch.Wait();
 }
 
 }  // namespace flutter
diff --git a/shell/platform/android/external_view_embedder/external_view_embedder.h b/shell/platform/android/external_view_embedder/external_view_embedder.h
index 278d7693e7661..2ec13297bb9ad 100644
--- a/shell/platform/android/external_view_embedder/external_view_embedder.h
+++ b/shell/platform/android/external_view_embedder/external_view_embedder.h
@@ -7,6 +7,7 @@
 
 #include 
 
+#include "flutter/common/task_runners.h"
 #include "flutter/flow/embedded_views.h"
 #include "flutter/flow/rtree.h"
 #include "flutter/shell/platform/android/context/android_context.h"
@@ -32,7 +33,8 @@ class AndroidExternalViewEmbedder final : public ExternalViewEmbedder {
   AndroidExternalViewEmbedder(
       const AndroidContext& android_context,
       std::shared_ptr jni_facade,
-      std::shared_ptr surface_factory);
+      std::shared_ptr surface_factory,
+      TaskRunners task_runners);
 
   // |ExternalViewEmbedder|
   void PrerollCompositeEmbeddedView(
@@ -99,6 +101,9 @@ class AndroidExternalViewEmbedder final : public ExternalViewEmbedder {
   // Holds surfaces. Allows to recycle surfaces or allocate new ones.
   const std::unique_ptr surface_pool_;
 
+  // The task runners.
+  const TaskRunners task_runners_;
+
   // The size of the root canvas.
   SkISize frame_size_;
 
@@ -126,6 +131,11 @@ class AndroidExternalViewEmbedder final : public ExternalViewEmbedder {
   // The number of platform views in the previous frame.
   int64_t previous_frame_view_count_;
 
+  // Destroys the surfaces created from the surface factory.
+  // This method schedules a task on the platform thread, and waits for
+  // the task until it completes.
+  void DestroySurfaces();
+
   // Resets the state.
   void Reset();
 
diff --git a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc
index 0f7043b41993a..fa0e65a9f1dd7 100644
--- a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc
+++ b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc
@@ -87,12 +87,24 @@ fml::RefPtr GetThreadMergerFromRasterThread(
                                                       rasterizer_queue_id);
 }
 
+TaskRunners GetTaskRunnersForFixture() {
+  fml::MessageLoop::EnsureInitializedForCurrentThread();
+  auto& loop = fml::MessageLoop::GetCurrent();
+  return {
+      "test",
+      loop.GetTaskRunner(),  // platform
+      loop.GetTaskRunner(),  // raster
+      loop.GetTaskRunner(),  // ui
+      loop.GetTaskRunner()   // io
+  };
+}
+
 TEST(AndroidExternalViewEmbedder, GetCurrentCanvases) {
   auto jni_mock = std::make_shared();
 
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, jni_mock, nullptr);
+      android_context, jni_mock, nullptr, GetTaskRunnersForFixture());
   fml::Thread rasterizer_thread("rasterizer");
   auto raster_thread_merger =
       GetThreadMergerFromPlatformThread(&rasterizer_thread);
@@ -117,7 +129,7 @@ TEST(AndroidExternalViewEmbedder, GetCurrentCanvasesCompositeOrder) {
 
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, jni_mock, nullptr);
+      android_context, jni_mock, nullptr, GetTaskRunnersForFixture());
   fml::Thread rasterizer_thread("rasterizer");
   auto raster_thread_merger =
       GetThreadMergerFromPlatformThread(&rasterizer_thread);
@@ -140,7 +152,7 @@ TEST(AndroidExternalViewEmbedder, GetCurrentCanvasesCompositeOrder) {
 TEST(AndroidExternalViewEmbedder, CompositeEmbeddedView) {
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, nullptr, nullptr);
+      android_context, nullptr, nullptr, GetTaskRunnersForFixture());
 
   ASSERT_EQ(nullptr, embedder->CompositeEmbeddedView(0));
   embedder->PrerollCompositeEmbeddedView(
@@ -156,7 +168,7 @@ TEST(AndroidExternalViewEmbedder, CompositeEmbeddedView) {
 TEST(AndroidExternalViewEmbedder, CancelFrame) {
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, nullptr, nullptr);
+      android_context, nullptr, nullptr, GetTaskRunnersForFixture());
 
   embedder->PrerollCompositeEmbeddedView(
       0, std::make_unique());
@@ -170,7 +182,7 @@ TEST(AndroidExternalViewEmbedder, RasterizerRunsOnPlatformThread) {
   auto jni_mock = std::make_shared();
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, jni_mock, nullptr);
+      android_context, jni_mock, nullptr, GetTaskRunnersForFixture());
 
   fml::Thread rasterizer_thread("rasterizer");
   auto raster_thread_merger =
@@ -204,7 +216,7 @@ TEST(AndroidExternalViewEmbedder, RasterizerRunsOnRasterizerThread) {
   auto jni_mock = std::make_shared();
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, jni_mock, nullptr);
+      android_context, jni_mock, nullptr, GetTaskRunnersForFixture());
 
   fml::Thread rasterizer_thread("rasterizer");
   auto raster_thread_merger =
@@ -225,7 +237,7 @@ TEST(AndroidExternalViewEmbedder, PlatformViewRect) {
 
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, jni_mock, nullptr);
+      android_context, jni_mock, nullptr, GetTaskRunnersForFixture());
   fml::Thread rasterizer_thread("rasterizer");
   auto raster_thread_merger =
       GetThreadMergerFromPlatformThread(&rasterizer_thread);
@@ -253,7 +265,7 @@ TEST(AndroidExternalViewEmbedder, PlatformViewRectChangedParams) {
 
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, jni_mock, nullptr);
+      android_context, jni_mock, nullptr, GetTaskRunnersForFixture());
   fml::Thread rasterizer_thread("rasterizer");
   auto raster_thread_merger =
       GetThreadMergerFromPlatformThread(&rasterizer_thread);
@@ -328,7 +340,7 @@ TEST(AndroidExternalViewEmbedder, SubmitFrame) {
         return android_surface_mock;
       });
   auto embedder = std::make_unique(
-      *android_context, jni_mock, surface_factory);
+      *android_context, jni_mock, surface_factory, GetTaskRunnersForFixture());
 
   auto raster_thread_merger = GetThreadMergerFromPlatformThread();
 
@@ -521,7 +533,7 @@ TEST(AndroidExternalViewEmbedder, SubmitFrameOverlayComposition) {
         return android_surface_mock;
       });
   auto embedder = std::make_unique(
-      *android_context, jni_mock, surface_factory);
+      *android_context, jni_mock, surface_factory, GetTaskRunnersForFixture());
 
   auto raster_thread_merger = GetThreadMergerFromPlatformThread();
 
@@ -623,7 +635,7 @@ TEST(AndroidExternalViewEmbedder, SubmitFramePlatformViewWithoutAnyOverlay) {
         return android_surface_mock;
       });
   auto embedder = std::make_unique(
-      *android_context, jni_mock, surface_factory);
+      *android_context, jni_mock, surface_factory, GetTaskRunnersForFixture());
 
   auto raster_thread_merger = GetThreadMergerFromPlatformThread();
 
@@ -662,7 +674,7 @@ TEST(AndroidExternalViewEmbedder, DoesNotCallJNIPlatformThreadOnlyMethods) {
 
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, jni_mock, nullptr);
+      android_context, jni_mock, nullptr, GetTaskRunnersForFixture());
 
   // While on the raster thread, don't make JNI calls as these methods can only
   // run on the platform thread.
@@ -711,7 +723,7 @@ TEST(AndroidExternalViewEmbedder, DestroyOverlayLayersOnSizeChange) {
       });
 
   auto embedder = std::make_unique(
-      *android_context, jni_mock, surface_factory);
+      *android_context, jni_mock, surface_factory, GetTaskRunnersForFixture());
   fml::Thread rasterizer_thread("rasterizer");
   auto raster_thread_merger =
       GetThreadMergerFromPlatformThread(&rasterizer_thread);
@@ -798,7 +810,7 @@ TEST(AndroidExternalViewEmbedder, DoesNotDestroyOverlayLayersOnSizeChange) {
       });
 
   auto embedder = std::make_unique(
-      *android_context, jni_mock, surface_factory);
+      *android_context, jni_mock, surface_factory, GetTaskRunnersForFixture());
 
   // ------------------ First frame ------------------ //
   {
@@ -855,7 +867,7 @@ TEST(AndroidExternalViewEmbedder, SupportsDynamicThreadMerging) {
   auto jni_mock = std::make_shared();
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, jni_mock, nullptr);
+      android_context, jni_mock, nullptr, GetTaskRunnersForFixture());
   ASSERT_TRUE(embedder->SupportsDynamicThreadMerging());
 }
 
@@ -863,7 +875,7 @@ TEST(AndroidExternalViewEmbedder, DisableThreadMerger) {
   auto jni_mock = std::make_shared();
   auto android_context = AndroidContext(AndroidRenderingAPI::kSoftware);
   auto embedder = std::make_unique(
-      android_context, jni_mock, nullptr);
+      android_context, jni_mock, nullptr, GetTaskRunnersForFixture());
 
   fml::Thread platform_thread("platform");
   auto raster_thread_merger = GetThreadMergerFromRasterThread(&platform_thread);
@@ -919,7 +931,7 @@ TEST(AndroidExternalViewEmbedder, Teardown) {
       });
 
   auto embedder = std::make_unique(
-      *android_context, jni_mock, surface_factory);
+      *android_context, jni_mock, surface_factory, GetTaskRunnersForFixture());
   fml::Thread rasterizer_thread("rasterizer");
   auto raster_thread_merger =
       GetThreadMergerFromPlatformThread(&rasterizer_thread);
diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
index 6d16ad31f84b6..128eb5c6a8e8d 100644
--- a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
+++ b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
@@ -11,7 +11,6 @@
 import android.graphics.ImageDecoder;
 import android.graphics.SurfaceTexture;
 import android.os.Build;
-import android.os.Handler;
 import android.os.Looper;
 import android.util.Size;
 import android.view.Surface;
@@ -42,7 +41,6 @@
 import java.util.Locale;
 import java.util.Set;
 import java.util.concurrent.CopyOnWriteArraySet;
-import java.util.concurrent.atomic.AtomicReference;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 /**
@@ -74,7 +72,7 @@
  *
  * 
{@code
  * // Instantiate FlutterJNI and attach to the native side.
- * FlutterJNI flutterJNI = new FlutterJNI(Looper.getMainLooper());
+ * FlutterJNI flutterJNI = new FlutterJNI();
  * flutterJNI.attachToNative();
  *
  * // Use FlutterJNI as desired. flutterJNI.dispatchPointerDataPacket(...);
@@ -108,13 +106,11 @@ public class FlutterJNI {
   // platform thread and doesn't require locking.
   private ReentrantReadWriteLock shellHolderLock = new ReentrantReadWriteLock();
 
-  /** @param looper The main looper. Typically, Looper.getMainLooper(). */
-  public FlutterJNI(@NonNull Looper looper) {
-    mainLooper = looper;
-  }
-
+  // Prefer using the FlutterJNI.Factory so it's easier to test.
   public FlutterJNI() {
-    this(Looper.getMainLooper());
+    // We cache the main looper so that we can ensure calls are made on the main thread
+    // without consistently paying the synchronization cost of getMainLooper().
+    mainLooper = Looper.getMainLooper();
   }
 
   /**
@@ -1173,29 +1169,14 @@ public FlutterOverlaySurface createOverlaySurface() {
   }
 
   @SuppressWarnings("unused")
-  public void destroyOverlaySurfaces() throws Exception {
-    // Normally, this method is called on the Android main thread.
-    //
-    // However, it may be called from a different thread after the thread merger lease expired
-    // and the rasterizer is being torn down.
-    //
-    // The platform view embedder may keep these surfaces even after the lease have expired in
-    // case they are used in a future frame that contains platform views.
-    //
-    // This is particularly an issue when a "cached" engine is used. In this case, this method
-    // would not be called if it requires to run on the main thread. For this reason, this
-    // method hops to the Android main thread if necessary.
-    //
-    // See Rasterizer::Teardown in C++, and FlutterEngineCache in Java.
-    runOnLooper(
-        () -> {
-          if (platformViewsController == null) {
-            throw new RuntimeException(
-                "platformViewsController must be set before attempting to destroy an overlay surface");
-          }
-          platformViewsController.destroyOverlaySurfaces();
-        },
-        mainLooper);
+  @UiThread
+  public void destroyOverlaySurfaces() {
+    ensureRunningOnMainThread();
+    if (platformViewsController == null) {
+      throw new RuntimeException(
+          "platformViewsController must be set before attempting to destroy an overlay surface");
+    }
+    platformViewsController.destroyOverlaySurfaces();
   }
   // ----- End Engine Lifecycle Support ----
 
@@ -1425,42 +1406,6 @@ private void ensureRunningOnMainThread() {
     }
   }
 
-  /**
-   * Causes the runnable r to be run on the thread associated with the given looper l. Then, it
-   * waits for the runnable to run.
-   *
-   * 
If the runnable throws, then the exception is captured and rethrown in the current thread.
-   *
-   * @param r The runnable that will be executed.
-   * @param l The looper where the runnable is added.
-   */
-  private void runOnLooper(Runnable r, Looper l) throws Exception {
-    if (Looper.myLooper() == l) {
-      r.run();
-      return;
-    }
-    final AtomicReference exception = new AtomicReference<>();
-    final Handler handler = new Handler(l);
-    handler.post(
-        () -> {
-          try {
-            r.run();
-          } catch (Exception e) {
-            exception.set(e);
-          }
-          synchronized (handler) {
-            handler.notify();
-          }
-        });
-    synchronized (handler) {
-      handler.wait();
-    }
-    if (exception.get() != null) {
-      // Rethrow the exception on the current thread.
-      throw exception.get();
-    }
-  }
-
   /**
    * Delegate responsible for creating and updating Android-side caches of Flutter's semantics tree
    * and custom accessibility actions.
diff --git a/shell/platform/android/platform_view_android.cc b/shell/platform/android/platform_view_android.cc
index c3d4c696628f4..97c58de4c3298 100644
--- a/shell/platform/android/platform_view_android.cc
+++ b/shell/platform/android/platform_view_android.cc
@@ -14,13 +14,12 @@
 #include "flutter/shell/platform/android/android_external_texture_gl.h"
 #include "flutter/shell/platform/android/android_surface_gl.h"
 #include "flutter/shell/platform/android/android_surface_software.h"
-#include "flutter/shell/platform/android/external_view_embedder/external_view_embedder.h"
-#include "flutter/shell/platform/android/surface/android_surface.h"
-#include "flutter/shell/platform/android/surface/snapshot_surface_producer.h"
-
 #include "flutter/shell/platform/android/context/android_context.h"
+#include "flutter/shell/platform/android/external_view_embedder/external_view_embedder.h"
 #include "flutter/shell/platform/android/jni/platform_view_android_jni.h"
 #include "flutter/shell/platform/android/platform_message_response_android.h"
+#include "flutter/shell/platform/android/surface/android_surface.h"
+#include "flutter/shell/platform/android/surface/snapshot_surface_producer.h"
 #include "flutter/shell/platform/android/vsync_waiter_android.h"
 
 namespace flutter {
@@ -255,7 +254,8 @@ std::unique_ptr PlatformViewAndroid::CreateRenderingSurface() {
 std::shared_ptr
 PlatformViewAndroid::CreateExternalViewEmbedder() {
   return std::make_shared(
-      *android_context_, jni_facade_, surface_factory_);
+      *android_context_, jni_facade_, surface_factory_,
+      std::move(task_runners_));
 }
 
 // |PlatformView|
diff --git a/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java b/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
index dbfd45f26e200..5f057c36609a0 100644
--- a/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
+++ b/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
@@ -10,10 +10,7 @@
 import android.content.Context;
 import android.content.res.Configuration;
 import android.content.res.Resources;
-import android.os.Handler;
 import android.os.LocaleList;
-import android.os.Looper;
-import android.os.Message;
 import io.flutter.embedding.engine.dart.DartExecutor;
 import io.flutter.embedding.engine.mutatorsstack.FlutterMutatorsStack;
 import io.flutter.embedding.engine.renderer.FlutterUiDisplayListener;
@@ -23,7 +20,6 @@
 import java.nio.ByteBuffer;
 import java.util.Locale;
 import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.atomic.AtomicReference;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.robolectric.RobolectricTestRunner;
@@ -249,47 +245,4 @@ public void invokePlatformMessageResponseCallback__wantsDirectBuffer() {
     ByteBuffer buffer = ByteBuffer.allocate(4);
     flutterJNI.invokePlatformMessageResponseCallback(0, buffer, buffer.position());
   }
-
-  @Test
-  public void destroyOverlaySurfaces__calledFromDifferentThread() throws Exception {
-    AtomicReference flutterJNI = new AtomicReference<>();
-    PlatformViewsController platformViewsController = mock(PlatformViewsController.class);
-
-    Object lock = new Object();
-    // This thread acts as the Android main thread.
-    // This is required because the test itself runs on the main thread, and without this
-    // workaround, a deadlock is produced.
-    Thread mainThreadImpostor =
-        new Thread(
-            () -> {
-              Looper.prepare();
-
-              flutterJNI.set(new FlutterJNI(Looper.myLooper()));
-              flutterJNI.get().setPlatformViewsController(platformViewsController);
-
-              synchronized (lock) {
-                lock.notify();
-              }
-
-              new Handler(Looper.myLooper()) {
-                public void handleMessage(Message msg) {
-                  msg.getCallback().run();
-                }
-              };
-              Looper.loop();
-            });
-
-    mainThreadImpostor.start();
-    synchronized (lock) {
-      lock.wait();
-    }
-
-    // --- Execute Test ---
-    flutterJNI.get().destroyOverlaySurfaces();
-
-    // --- Verify Results ---
-    verify(platformViewsController, times(1)).destroyOverlaySurfaces();
-
-    mainThreadImpostor.interrupt();
-  }
 }
diff --git a/tools/android_lint/project.xml b/tools/android_lint/project.xml
index b37e7f0029a4c..27c279ba89da7 100644
--- a/tools/android_lint/project.xml
+++ b/tools/android_lint/project.xml
@@ -52,8 +52,8 @@
     
     
     
-    
     
+    
     
     
     
@@ -178,8 +178,8 @@
     
     
     
-    
     
+    
     
     
     

From d60f166998f6419f21ad1c859dd58de47e7f5219 Mon Sep 17 00:00:00 2001
From: Emmanuel Garcia 
Date: Fri, 21 Jan 2022 16:17:45 -0800
Subject: [PATCH 09/10] Revert change

---
 tools/android_lint/project.xml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/android_lint/project.xml b/tools/android_lint/project.xml
index 27c279ba89da7..b37e7f0029a4c 100644
--- a/tools/android_lint/project.xml
+++ b/tools/android_lint/project.xml
@@ -52,8 +52,8 @@
     
     
     
-    
     
+    
     
     
     
@@ -178,8 +178,8 @@
     
     
     
-    
     
+    
     
     
     

From 0b22d375ae392efeede9b036e5ad6c42e0894de6 Mon Sep 17 00:00:00 2001
From: Emmanuel Garcia 
Date: Wed, 26 Jan 2022 11:19:18 -0800
Subject: [PATCH 10/10] Add FML_USED_ON_EMBEDDER

---
 .../external_view_embedder/external_view_embedder_unittests.cc  | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc
index fa0e65a9f1dd7..57966440d0d05 100644
--- a/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc
+++ b/shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#define FML_USED_ON_EMBEDDER
+
 #include 
 #include "flutter/shell/platform/android/external_view_embedder/external_view_embedder.h"