Revert DeviceState callback to main thread in FFP.

import android.util.Log;

import android.util.SparseIntArray;

import androidx.annotation.BinderThread;

import androidx.annotation.GuardedBy;

import androidx.annotation.MainThread;

import androidx.annotation.NonNull;

import androidx.annotation.VisibleForTesting;

import androidx.window.common.layout.DisplayFoldFeatureCommon;

import com.android.internal.R;

import com.android.window.flags.Flags;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.Objects;

import java.util.Optional;

import java.util.concurrent.Executor;

import java.util.function.Consumer;

/**

     * "rear display". Concurrent mode for example is activated via public API and can be active in

     * both the "open" and "half folded" device states.

     */

    // TODO: b/337820752 - Add @GuardedBy("mCurrentDeviceStateLock") after flag cleanup.

    private DeviceState mCurrentDeviceState = INVALID_DEVICE_STATE;

    /**

     * Lock to synchronize access to {@link #mCurrentDeviceState}.

     *

     * <p>This lock is used to ensure thread-safety when accessing and modifying the

     * {@link #mCurrentDeviceState} field. It is acquired by both the binder thread (if

     * {@link Flags#wlinfoOncreate()} is enabled) and the main thread (if

     * {@link Flags#wlinfoOncreate()} is disabled) to prevent race conditions and

     * ensure data consistency.

     */

    private final Object mCurrentDeviceStateLock = new Object();

    @NonNull

    private final RawFoldingFeatureProducer mRawFoldSupplier;

        // The GuardedBy analysis is intra-procedural, meaning it doesn’t consider the getData()

        // implementation. See https://errorprone.info/bugpattern/GuardedBy for limitations.

        @SuppressWarnings("GuardedBy")

        @BinderThread // When Flags.wlinfoOncreate() is enabled.

        @MainThread // When Flags.wlinfoOncreate() is disabled.

        @MainThread

        @Override

        public void onDeviceStateChanged(@NonNull DeviceState state) {

            synchronized (mCurrentDeviceStateLock) {

            mCurrentDeviceState = state;

            mRawFoldSupplier.getData(DeviceStateManagerFoldingFeatureProducer.this

                    ::notifyFoldingFeatureChangeLocked);

        }

        }

    };

    public DeviceStateManagerFoldingFeatureProducer(@NonNull Context context,

                new DeviceStateMapper(context, deviceStateManager.getSupportedDeviceStates());

        if (!mDeviceStateMapper.isDeviceStateToPostureMapEmpty()) {

            final Executor executor =

                    Flags.wlinfoOncreate() ? Runnable::run : context.getMainExecutor();

            Objects.requireNonNull(deviceStateManager)

                    .registerCallback(executor, mDeviceStateCallback);

                    .registerCallback(context.getMainExecutor(), mDeviceStateCallback);

        }

    }

    @Override

    protected void onListenersChanged() {

        super.onListenersChanged();

        synchronized (mCurrentDeviceStateLock) {

        if (hasListeners()) {

            mRawFoldSupplier.addDataChangedCallback(this::notifyFoldingFeatureChangeLocked);

        } else {

            mRawFoldSupplier.removeDataChangedCallback(this::notifyFoldingFeatureChangeLocked);

        }

    }

    }

    @NonNull

    private DeviceState getCurrentDeviceState() {

        synchronized (mCurrentDeviceStateLock) {

        return mCurrentDeviceState;

    }

    }

    @NonNull

    @Override

        });

    }

    @GuardedBy("mCurrentDeviceStateLock")

    private void notifyFoldingFeatureChangeLocked(String displayFeaturesString) {

        final DeviceState state = mCurrentDeviceState;

        if (!mDeviceStateMapper.isDeviceStateValid(state)) {

        return parseListFromString(displayFeaturesString, hingeState);

    }

    /**

     * Internal class to map device states to corresponding postures.

     *

     * <p>This class encapsulates the logic for mapping device states to postures. The mapping is

     * immutable after initialization to ensure thread safety.

     */

    /** Internal class to map device states to corresponding postures. */

    private static class DeviceStateMapper {

        /**

         * Emulated device state

         * {@link DeviceStateManager.DeviceStateCallback#onDeviceStateChanged(DeviceState)} to

         * {@link CommonFoldingFeature.State} map.

         *

         * <p>This map must be immutable after initialization to ensure thread safety, as it may be

         * accessed from multiple threads. Modifications should only occur during object

         * construction.

         */

        private final SparseIntArray mDeviceStateToPostureMap = new SparseIntArray();

        /**

         * The list of device states that are supported.

         *

         * <p>This list must be immutable after initialization to ensure thread safety.

         */

        /** The list of device states that are supported. */

        @NonNull

        private final List<DeviceState> mSupportedStates;

import android.content.res.Resources

import android.hardware.devicestate.DeviceState

import android.hardware.devicestate.DeviceStateManager

import android.platform.test.annotations.DisableFlags

import android.platform.test.annotations.EnableFlags

import android.platform.test.flag.junit.SetFlagsRule

import androidx.test.ext.junit.runners.AndroidJUnit4

import androidx.window.common.layout.CommonFoldingFeature

import androidx.window.common.layout.CommonFoldingFeature.COMMON_STATE_FLAT

import androidx.window.common.layout.DisplayFoldFeatureCommon.DISPLAY_FOLD_FEATURE_PROPERTY_SUPPORTS_HALF_OPENED

import androidx.window.common.layout.DisplayFoldFeatureCommon.DISPLAY_FOLD_FEATURE_TYPE_SCREEN_FOLD_IN

import com.android.internal.R

import com.android.window.flags.Flags

import com.google.common.truth.Truth.assertThat

import java.util.Optional

import java.util.concurrent.Executor

import java.util.function.Consumer

import org.junit.Rule

import org.junit.Test

import org.junit.runner.RunWith

import org.mockito.ArgumentCaptor

import org.mockito.kotlin.any

import org.mockito.kotlin.doAnswer

import org.mockito.kotlin.doReturn

 */

@RunWith(AndroidJUnit4::class)

class DeviceStateManagerFoldingFeatureProducerTest {

    @get:Rule

    val setFlagsRule: SetFlagsRule = SetFlagsRule()

    private val mMockDeviceStateManager = mock<DeviceStateManager>()

    private val mMockResources = mock<Resources> {

        on { getStringArray(R.array.config_device_state_postures) } doReturn DEVICE_STATE_POSTURES

    }

    @Test

    @DisableFlags(Flags.FLAG_WLINFO_ONCREATE)

    fun testRegisterCallback_whenWlinfoOncreateIsDisabled_usesMainExecutor() {

    fun testRegisterCallback_usesMainExecutor() {

        DeviceStateManagerFoldingFeatureProducer(

            mMockContext,

            mRawFoldSupplier,

        verify(mMockDeviceStateManager).registerCallback(eq(mMockContext.mainExecutor), any())

    }

    @Test

    @EnableFlags(Flags.FLAG_WLINFO_ONCREATE)

    fun testRegisterCallback_whenWlinfoOncreateIsEnabled_usesRunnableRun() {

        val executorCaptor = ArgumentCaptor.forClass(Executor::class.java)

        val runnable = mock<Runnable>()

        DeviceStateManagerFoldingFeatureProducer(

            mMockContext,

            mRawFoldSupplier,

            mMockDeviceStateManager,

        )

        verify(mMockDeviceStateManager).registerCallback(executorCaptor.capture(), any())

        executorCaptor.value.execute(runnable)

        verify(runnable).run()

    }

    @Test

    fun testGetCurrentData_validCurrentState_returnsFoldingFeatureWithState() {

        val ffp = DeviceStateManagerFoldingFeatureProducer(