Reapply "Fix thread starvation caused by not yielding or using an inappropriate thread pool (#2955)"

This reverts commit 1d7c838ae6.

app/src/main/java/eu/kanade/tachiyomi/ui/main/MainActivity.kt

@@ -131,8 +131,6 @@ class MainActivity : BaseActivity() {
 
         super.onCreate(savedInstanceState)
 
-        val didMigration = Migrator.awaitAndRelease()
-
         // Do not let the launcher create a new activity http://stackoverflow.com/questions/16283079
         if (!isTaskRoot) {
             finish()
@@ -140,6 +138,11 @@ class MainActivity : BaseActivity() {
         }
 
         setComposeContent {
+            var didMigration by remember { mutableStateOf<Boolean?>(null) }
+            LaunchedEffect(Unit) {
+                didMigration = Migrator.awaitAndRelease()
+            }
+
             val context = LocalContext.current
 
             var incognito by remember { mutableStateOf(getIncognitoState.await(null)) }
@@ -242,7 +245,7 @@ class MainActivity : BaseActivity() {
                 ShowOnboarding()
             }
 
-            var showChangelog by remember { mutableStateOf(didMigration && !BuildConfig.DEBUG) }
+            var showChangelog by remember { mutableStateOf(didMigration == true && !BuildConfig.DEBUG) }
             if (showChangelog) {
                 AlertDialog(
                     onDismissRequest = { showChangelog = false },

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt

@@ -145,18 +145,25 @@ class ReaderViewModel @JvmOverloads constructor(
 
     private var chapterToDownload: Download? = null
 
-    private val unfilteredChapterList by lazy {
-        val manga = manga!!
-        runBlocking { getChaptersByMangaId.await(manga.id, applyScanlatorFilter = false) }
+    private var unfilteredChapterListCache: List<tachiyomi.domain.chapter.model.Chapter>? = null
+    private suspend fun getUnfilteredChapterList(): List<tachiyomi.domain.chapter.model.Chapter> {
+        if (unfilteredChapterListCache == null) {
+            val manga = manga!!
+            unfilteredChapterListCache = getChaptersByMangaId.await(manga.id, applyScanlatorFilter = false)
+        }
+        return unfilteredChapterListCache!!
     }
 
     /**
      * Chapter list for the active manga. It's retrieved lazily and should be accessed for the first
      * time in a background thread to avoid blocking the UI.
      */
-    private val chapterList by lazy {
+    private var chapterListCache: List<ReaderChapter>? = null
+    private suspend fun getChapterList(): List<ReaderChapter> {
+        chapterListCache?.let { return it }
+
         val manga = manga!!
-        val chapters = runBlocking { getChaptersByMangaId.await(manga.id, applyScanlatorFilter = true) }
+        val chapters = getChaptersByMangaId.await(manga.id, applyScanlatorFilter = true)
 
         val selectedChapter = chapters.find { it.id == chapterId }
             ?: error("Requested chapter of id $chapterId not found in chapter list")
@@ -205,7 +212,7 @@ class ReaderViewModel @JvmOverloads constructor(
             else -> chapters
         }
 
-        chaptersForReader
+        val result = chaptersForReader
             .sortedWith(getChapterSort(manga, sortDescending = false))
             .run {
                 if (readerPreferences.skipDupe().get()) {
@@ -223,6 +230,8 @@ class ReaderViewModel @JvmOverloads constructor(
             }
             .map { it.toDbChapter() }
             .map(::ReaderChapter)
+        chapterListCache = result
+        return result
     }
 
     private val incognitoMode: Boolean by lazy { getIncognitoState.await(manga?.source) }
@@ -288,7 +297,7 @@ class ReaderViewModel @JvmOverloads constructor(
                     val source = sourceManager.getOrStub(manga.source)
                     loader = ChapterLoader(context, downloadManager, downloadProvider, manga, source)
 
-                    loadChapter(loader!!, chapterList.first { chapterId == it.chapter.id })
+                    loadChapter(loader!!, getChapterList().first { chapterId == it.chapter.id })
                     Result.success(true)
                 } else {
                     // Unlikely but okay
@@ -313,6 +322,7 @@ class ReaderViewModel @JvmOverloads constructor(
     ): ViewerChapters {
         loader.loadChapter(chapter)
 
+        val chapterList = getChapterList()
         val chapterPos = chapterList.indexOf(chapter)
         val newChapters = ViewerChapters(
             chapter,
@@ -511,11 +521,12 @@ class ReaderViewModel @JvmOverloads constructor(
      * If both conditions are satisfied enqueues chapter for delete
      * @param currentChapter current chapter, which is going to be marked as read.
      */
-    private fun deleteChapterIfNeeded(currentChapter: ReaderChapter) {
+    private suspend fun deleteChapterIfNeeded(currentChapter: ReaderChapter) {
         val removeAfterReadSlots = downloadPreferences.removeAfterReadSlots().get()
         if (removeAfterReadSlots == -1) return
 
         // Determine which chapter should be deleted and enqueue
+        val chapterList = getChapterList()
         val currentChapterPosition = chapterList.indexOf(currentChapter)
         val chapterToDelete = chapterList.getOrNull(currentChapterPosition - removeAfterReadSlots)
 
@@ -566,7 +577,7 @@ class ReaderViewModel @JvmOverloads constructor(
             .contains(LibraryPreferences.MARK_DUPLICATE_CHAPTER_READ_EXISTING)
         if (!markDuplicateAsRead) return
 
-        val duplicateUnreadChapters = unfilteredChapterList
+        val duplicateUnreadChapters = getUnfilteredChapterList()
             .mapNotNull { chapter ->
                 if (
                     !chapter.read &&
@@ -679,7 +690,7 @@ class ReaderViewModel @JvmOverloads constructor(
      */
     fun setMangaReadingMode(readingMode: ReadingMode) {
         val manga = manga ?: return
-        runBlocking(Dispatchers.IO) {
+        viewModelScope.launchIO {
             setMangaViewerFlags.awaitSetReadingMode(manga.id, readingMode.flagValue.toLong())
             val currChapters = state.value.viewerChapters
             if (currChapters != null) {

app/src/main/java/eu/kanade/tachiyomi/ui/updates/UpdatesScreenModel.kt

@@ -239,7 +239,7 @@ class UpdatesScreenModel(
         }
     }
 
-    private fun startDownloadingNow(chapterId: Long) {
+    private suspend fun startDownloadingNow(chapterId: Long) {
         downloadManager.startDownloadNow(chapterId)
     }