Blind fix for InterruptedException in runBlocking.

KeyguardRemotePreviewManager was using runBlocking to make sure a block
of code that destroys the renderer is called, on the main thread, before
proceeding. It seems like this was exposed to InterruptedExceptions
thrown when the main thread was getting interrupted by something
(presumably something in the framework interrupts blockers of the main
thread under unknown conditions).

The _blind_ fix (blind because it's not clear how to reproduce these
conditions) is to move the work to use launch instead of runBlocking
as we're still interested in doing the work on the main thread (so
listeners are removed from upstream dependencies of the renderer on a
known thread to avoid race conditions) but can live without the
atomicity provided by runBlocking.

Fix: 271691762
Test: manually verified that the lock screen preview in wallpaper
picker's various sections still seems to work, even when accessed
multiple times.

Change-Id: I7f0b1bd46986d87baa8e81c807ff8a7aa56e7959

packages/SystemUI/src/com/android/systemui/keyguard/ui/preview/KeyguardRemotePreviewManager.kt

@@ -26,18 +26,21 @@ import android.util.ArrayMap
 import android.util.Log
 import androidx.annotation.VisibleForTesting
 import com.android.systemui.dagger.SysUISingleton
+import com.android.systemui.dagger.qualifiers.Application
 import com.android.systemui.dagger.qualifiers.Background
 import com.android.systemui.dagger.qualifiers.Main
 import com.android.systemui.shared.quickaffordance.shared.model.KeyguardQuickAffordancePreviewConstants
 import javax.inject.Inject
 import kotlinx.coroutines.CoroutineDispatcher
-import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
 
 @SysUISingleton
 class KeyguardRemotePreviewManager
 @Inject
 constructor(
     private val previewRendererFactory: KeyguardPreviewRendererFactory,
+    @Application private val applicationScope: CoroutineScope,
     @Main private val mainDispatcher: CoroutineDispatcher,
     @Background private val backgroundHandler: Handler,
 ) {
@@ -55,7 +58,13 @@ constructor(
 
             // Destroy any previous renderer associated with this token.
             activePreviews[renderer.hostToken]?.let { destroyObserver(it) }
-            observer = PreviewLifecycleObserver(renderer, mainDispatcher, ::destroyObserver)
+            observer =
+                PreviewLifecycleObserver(
+                    renderer,
+                    applicationScope,
+                    mainDispatcher,
+                    ::destroyObserver,
+                )
             activePreviews[renderer.hostToken] = observer
             renderer.render()
             renderer.hostToken?.linkToDeath(observer, 0)
@@ -92,13 +101,18 @@ constructor(
 
     private class PreviewLifecycleObserver(
         private val renderer: KeyguardPreviewRenderer,
+        private val scope: CoroutineScope,
         private val mainDispatcher: CoroutineDispatcher,
         private val requestDestruction: (PreviewLifecycleObserver) -> Unit,
     ) : Handler.Callback, IBinder.DeathRecipient {
 
-        private var isDestroyed = false
+        private var isDestroyedOrDestroying = false
 
         override fun handleMessage(message: Message): Boolean {
+            if (isDestroyedOrDestroying) {
+                return true
+            }
+
             when (message.what) {
                 KeyguardQuickAffordancePreviewConstants.MESSAGE_ID_SLOT_SELECTED -> {
                     message.data
@@ -118,14 +132,14 @@ constructor(
         }
 
         fun onDestroy(): IBinder? {
-            if (isDestroyed) {
+            if (isDestroyedOrDestroying) {
                 return null
             }
 
-            isDestroyed = true
+            isDestroyedOrDestroying = true
             val hostToken = renderer.hostToken
             hostToken?.unlinkToDeath(this, 0)
-            runBlocking(mainDispatcher) { renderer.destroy() }
+            scope.launch(mainDispatcher) { renderer.destroy() }
             return hostToken
         }
     }

packages/SystemUI/tests/src/com/android/systemui/keyguard/CustomizationProviderTest.kt

@@ -189,6 +189,7 @@ class CustomizationProviderTest : SysuiTestCase() {
             )
         underTest.previewManager =
             KeyguardRemotePreviewManager(
+                applicationScope = testScope.backgroundScope,
                 previewRendererFactory = previewRendererFactory,
                 mainDispatcher = testDispatcher,
                 backgroundHandler = backgroundHandler,