优化

app/src/main/java/io/legado/app/ui/main/MainViewModel.kt

@@ -68,8 +68,8 @@ class MainViewModel(application: Application) : BaseViewModel(application) {
         }
     }
 
+    @Synchronized
     private fun updateToc() {
-        synchronized(this) {
         bookMap.forEach { bookEntry ->
             if (!updateList.contains(bookEntry.key)) {
                 val book = bookEntry.value
@@ -108,7 +108,6 @@ class MainViewModel(application: Application) : BaseViewModel(application) {
             }
         }
     }
-    }
 
     private fun cacheBook(webBook: WebBook, book: Book) {
         execute {