GLConsumer is already attached to a context for ne

Is SurfaceTexture attached to GLContext by default when created manually? If so, how?

Here is an example, I'm trying to create my own SurfaceTexture and set it to TextureView:

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        TextView textView = (TextView) findViewById(R.id.version);
        TextureView textureView = (TextureView) findViewById(R.id.texture);

        int[] arr = new int[1];
        GLES20.glGenTextures(1, arr, 0);
        int texName = arr[1];

        SurfaceTexture surfaceTexture = new SurfaceTexture(texName);
        textureView.setSurfaceTexture(surfaceTexture);
    }
}

I'm constantly getting:

E/GLConsumer: [unnamed-29058-0] attachToContext: GLConsumer is already attached to a context

And the exception:

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.dkarmazin.openglesversion, PID: 29058 java.lang.RuntimeException: Error during attachToGLContext (see logcat for details) at android.graphics.SurfaceTexture.attachToGLContext(SurfaceTexture.java:215) at android.view.GLES20TextureLayer.setSurfaceTexture(GLES20TextureLayer.java:86) at android.view.HardwareRenderer$Gl20Renderer.setSurfaceTexture(HardwareRenderer.java:2228) at android.view.TextureView.getHardwareLayer(TextureView.java:401) at android.view.View.getDisplayList(View.java:13443) at android.view.View.getDisplayList(View.java:13519) at android.view.View.draw(View.java:14297) at android.view.ViewGroup.drawChild(ViewGroup.java:3115) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2952) at android.view.View.getDisplayList(View.java:13472) at android.view.View.getDisplayList(View.java:13519) at android.view.View.draw(View.java:14297) at android.view.ViewGroup.drawChild(ViewGroup.java:3115) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2952) at android.view.View.draw(View.java:14583) at android.widget.FrameLayout.draw(FrameLayout.java:472) at android.view.View.getDisplayList(View.java:13477) at android.view.View.getDisplayList(View.java:13519) at android.view.View.draw(View.java:14297) at android.view.ViewGroup.drawChild(ViewGroup.java:3115) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2952) at android.view.View.draw(View.java:14583) at android.support.v7.widget.ActionBarOverlayLayout.draw(ActionBarOverlayLayout.java:444) at android.view.View.getDisplayList(View.java:13477) at android.view.View.getDisplayList(View.java:13519) at android.view.View.draw(View.java:14297) at android.view.ViewGroup.drawChild(ViewGroup.java:3115) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2952) at android.view.View.getDisplayList(View.java:13472) at android.view.View.getDisplayList(View.java:13519) at android.view.View.draw(View.java:14297) at android.view.ViewGroup.drawChild(ViewGroup.java:3115) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2952) at android.view.View.getDisplayList(View.java:13472) at android.view.View.getDisplayList(View.java:13519) at android.view.View.draw(View.java:14297) at android.view.ViewGroup.drawChild(ViewGroup.java:3115) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2952) at android.view.View.draw(View.java:14583) at android.widget.FrameLayout.draw(FrameLayout.java:472) at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2326) at android.view.View.getDisplayList(View.java:13477) at android.view.View.getDisplayList(View.java:13519) at android.view.HardwareRenderer$GlRenderer.buildDisplayList(HardwareRenderer.java:1577) at android.view.HardwareRenderer$GlRenderer.draw(HardwareRenderer.java:1449) at android.view.ViewRootImpl.draw(ViewRootImpl.java:2530) at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2402) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2019) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1079) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5948) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761) at android.view.Choreographer.doCallbacks(Choreographer.java:574) at android.view.Choreographer.doFrame(Choreographer.java:544) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747) at android.os.Handler.handleCallback(Handler.java:733) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5102) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) at dalvik.system.NativeStart.main(Native Method)

Calling detachFromGLContext on newly created SurfaceTexture object solves the problem, but that's rather confusing as I can confirm that attachToGLContext is never called in this scenario.

P.S. I know that TextureView has it's own SurfaceTexture by default. In this scenario I have to use own implementation that extends from SurfaceTexture.

I'll post an answer to my own question just in case someone else is facing the same issue.

Presumably, a new SurfaceTexture is attached to GLContext by default due to:

SurfaceTexture constructor calls to nativeInit
nativeInit corresponds to SurfaceTexture_init: https://android.googlesource.com/platform/frameworks/base.git/+/android-4.4.4_r2.0.1/core/jni/android/graphics/SurfaceTexture.cpp#337
SurfaceTexture_init creates a new GLConsumer here: https://android.googlesource.com/platform/frameworks/base.git/+/android-4.4.4_r2.0.1/core/jni/android/graphics/SurfaceTexture.cpp#239

Solution would be to manually detach this newly created SurfaceTexture from GLContext right after the call to a super constructor.

public class MySurfaceTexture extends SurfaceTexture {
    public MySurfaceTexture(int texName) {
        super(texName);
        init();
    }

    private void init() {
        super.detachFromGLContext();
    }
}

I looked up docs specifically for API-19, but you can follow the same path for other API levels.

In Android O there is a new constructor which doesn't attach immediately. Sounds like that's what you want. As your self-answer says, the previous constructors automatically attach to the current thread's GL context.