From 719e517dda851f8feaf3470f21406648f745eae3 Mon Sep 17 00:00:00 2001
From: Lauris van Rijn <laurisgh@vrijn.io>
Date: Fri, 29 Aug 2025 00:19:24 +0200
Subject: [PATCH] =?UTF-8?q?fix(androidauto):=20async=20handling=20of=20bro?=
 =?UTF-8?q?wseTree=20init=20instead=20of=20busy=E2=80=91loop?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Removed blocking `while (!browseTree.isInitialized){}` in
`onLoadChildren`. Added `waitForBrowseTree` and `onBrowseTreeInitialized`
helpers to queue pending results until browseTree is ready. All
browseTree assignments now call `onBrowseTreeInitialized()`. This avoids
ANRs and high CPU when Android Auto requests children before init.
---
 .../app/player/PlayerNotificationService.kt   | 64 +++++++++++++++----
 1 file changed, 52 insertions(+), 12 deletions(-)

diff --git a/android/app/src/main/java/com/audiobookshelf/app/player/PlayerNotificationService.kt b/android/app/src/main/java/com/audiobookshelf/app/player/PlayerNotificationService.kt
index e37e7147..5e3af81e 100644
--- a/android/app/src/main/java/com/audiobookshelf/app/player/PlayerNotificationService.kt
+++ b/android/app/src/main/java/com/audiobookshelf/app/player/PlayerNotificationService.kt
@@ -1087,6 +1087,26 @@ class PlayerNotificationService : MediaBrowserServiceCompat() {
   private val DOWNLOADS_ROOT = "__DOWNLOADS__"
   private val CONTINUE_ROOT = "__CONTINUE__"
   private lateinit var browseTree: BrowseTree
+  private val browseTreeInitListeners = mutableListOf<() -> Unit>()
+
+  private fun waitForBrowseTree(cb: () -> Unit)
+  {
+    if (this::browseTree.isInitialized)
+    {
+      cb()
+    }
+    else
+    {
+      browseTreeInitListeners += cb
+    }
+  }
+
+  private fun onBrowseTreeInitialized()
+  {
+    // Called after browseTree is assigned for the first time
+    browseTreeInitListeners.forEach { it.invoke() }
+    browseTreeInitListeners.clear()
+  }
 
   // Only allowing android auto or similar to access media browser service
   //  normal loading of audiobooks is handled in webview (not natively)
@@ -1257,6 +1277,7 @@ class PlayerNotificationService : MediaBrowserServiceCompat() {
                           mediaManager.serverLibraries,
                           mediaManager.allLibraryPersonalizationsDone
                   )
+          onBrowseTreeInitialized()
           val children =
                   browseTree[parentMediaId]?.map { item ->
                     Log.d(tag, "Found top menu item: ${item.description.title}")
@@ -1291,6 +1312,7 @@ class PlayerNotificationService : MediaBrowserServiceCompat() {
                         mediaManager.serverLibraries,
                         mediaManager.allLibraryPersonalizationsDone
                 )
+        onBrowseTreeInitialized()
         val children =
                 browseTree[parentMediaId]?.map { item ->
                   Log.d(tag, "Found top menu item: ${item.description.title}")
@@ -1303,22 +1325,40 @@ class PlayerNotificationService : MediaBrowserServiceCompat() {
         AbsLogger.info(tag, "onLoadChildren: Android auto data loaded")
         result.sendResult(children as MutableList<MediaBrowserCompat.MediaItem>?)
       }
-    } else if (parentMediaId == LIBRARIES_ROOT || parentMediaId == RECENTLY_ROOT) {
+    } else if (parentMediaId == LIBRARIES_ROOT || parentMediaId == RECENTLY_ROOT)
+    {
       Log.d(tag, "First load done: $firstLoadDone")
-      if (!firstLoadDone) {
+      if (!firstLoadDone)
+      {
         result.sendResult(null)
         return
       }
-      // Wait until top-menu is initialized
-      while (!this::browseTree.isInitialized) {}
-      val children =
-              browseTree[parentMediaId]?.map { item ->
-                Log.d(tag, "[MENU: $parentMediaId] Showing list item ${item.description.title}")
-                MediaBrowserCompat.MediaItem(
-                        item.description,
-                        MediaBrowserCompat.MediaItem.FLAG_BROWSABLE
-                )
-              }
+
+      if (!this::browseTree.isInitialized)
+      {
+        // ✅ good: detach and wait for init
+        result.detach()
+        waitForBrowseTree {
+          val children = browseTree[parentMediaId]?.map { item ->
+            Log.d(tag, "[MENU: $parentMediaId] Showing list item ${item.description.title}")
+            MediaBrowserCompat.MediaItem(
+              item.description,
+              MediaBrowserCompat.MediaItem.FLAG_BROWSABLE
+            )
+          }
+          result.sendResult(children as MutableList<MediaBrowserCompat.MediaItem>?)
+        }
+        return
+      }
+
+      // Already initialized: just return
+      val children = browseTree[parentMediaId]?.map { item ->
+        Log.d(tag, "[MENU: $parentMediaId] Showing list item ${item.description.title}")
+        MediaBrowserCompat.MediaItem(
+          item.description,
+          MediaBrowserCompat.MediaItem.FLAG_BROWSABLE
+        )
+      }
       result.sendResult(children as MutableList<MediaBrowserCompat.MediaItem>?)
     } else if (mediaManager.getIsLibrary(parentMediaId)) { // Load library items for library
       Log.d(tag, "Loading items for library $parentMediaId")