mobile/ebitenmobileview: ANR is reported on Android

[hajimehoshi]

Ebitengine Version

v2.10.0-alpha.3

Operating System

• Windows
• macOS
• Linux
• FreeBSD
• OpenBSD
• Android
• iOS
• Nintendo Switch
• PlayStation 5
• Xbox
• Web Browsers

Go Version (go version)

go1.25.1

What steps will reproduce the problem?

Not sure. We found this issue in the Play Console for an actual application "FIshing Paradiso".

What is the expected result?

No ANR (onPause should not freeze the app).

What happens instead?

ANR at onPause was reported

  #00  pc 0x000000000087269c  /data/app/~~G7qG_5I69yCU44Q1CJrYWg==/com.rpgsnack.fishingparadise-wpDpMJgABTjC7y26fKd9RQ==/split_config.arm64_v8a.apk (runtime.futex+651) (BuildId: cad8e8fc7ccdd6e7f41665b4f1cb9122e12a898e)
  at com.rpgsnack.runtime.ebitenmobileview.Ebitenmobileview.saveGPUResources (Native method)
  at com.rpgsnack.runtime.mobile.EbitenSurfaceView.onPause (EbitenSurfaceView.java:124)
  at com.rpgsnack.runtime.mobile.EbitenView.suspendGame (EbitenView.java:416)
  at com.rpgsnack.tsugunai.ContentView.onPause (ContentView.java:81)
  at com.rpgsnack.tsugunai.MainActivity.onPause (MainActivity.java:278)

Anything else you feel useful to add?

This ANR is not user-perceived ANR, so this should not be urgent.

Related #3215

CC @wasedaigo

[hajimehoshi]

Another fix candidate:

diff --git a/cmd/ebitenmobile/_files/EbitenSurfaceView.java b/cmd/ebitenmobile/_files/EbitenSurfaceView.java
index 34bcd14dc..27f5cf2a5 100644
--- a/cmd/ebitenmobile/_files/EbitenSurfaceView.java
+++ b/cmd/ebitenmobile/_files/EbitenSurfaceView.java
@@ -121,12 +121,18 @@ class EbitenSurfaceView extends GLSurfaceView implements Renderer {
 
     @Override
     public void onPause() {
-        Ebitenmobileview.saveGPUResources();
-        // Saving GPU resources is done in onDrawFrame.
-        // In the next onDrawFrame, Ebitengine restores GPU resources automatically.
-        // In theory, it is possible that onDrawFrame is invoked between saveGPUResources and super.onPause,
-        // and in thie case, GPU resources are restored before the context is actually lost.
-        // This is pretty unlikely, and even if it happens, the process is gracefully killed at Ebitenmobileview.onContextLost.
+        onPause(true);
+    }
+
+    public void onPause(boolean saveGPUResources) {
+        if (saveGPUResources) {
+            Ebitenmobileview.saveGPUResources();
+            // Saving GPU resources is done in onDrawFrame.
+            // In the next onDrawFrame, Ebitengine restores GPU resources automatically.
+            // In theory, it is possible that onDrawFrame is invoked between saveGPUResources and super.onPause,
+            // and in thie case, GPU resources are restored before the context is actually lost.
+            // This is pretty unlikely, and even if it happens, the process is gracefully killed at Ebitenmobileview.onContextLost.
+        }
         super.onPause();
     }
 }
diff --git a/cmd/ebitenmobile/_files/EbitenView.java b/cmd/ebitenmobile/_files/EbitenView.java
index 976b19f4c..b6c55d6c3 100644
--- a/cmd/ebitenmobile/_files/EbitenView.java
+++ b/cmd/ebitenmobile/_files/EbitenView.java
@@ -412,6 +412,16 @@ public class EbitenView extends ViewGroup implements InputManager.InputDeviceLis
     // It is recommended to call this when the application is being suspended e.g.,
     // Activity's onPause is called.
     public void suspendGame() {
+        suspendGame(true);
+    }
+
+    // suspendGame suspends the game.
+    // It is recommended to call this when the application is being suspended e.g.,
+    // Activity's onPause is called.
+    //
+    // saveGPUResources indicates whether GPU resources should be saved for recovery from context loss.
+    // If performance is critical and context loss is unlikely, set this to false.
+    public void suspendGame(boolean saveGPUResources) {
         this.inputManager.unregisterInputDeviceListener(this);
         this.ebitenSurfaceView.onPause();
         try {