Revert "Android: Don't hold gameFileCache lock during updateAdditionalMetadata"

This reverts commit fb265b610d.

The optimization in that commit is safe when the executor thread is
writing and the GUI thread is reading, but I had failed to take into
account that it's unsafe when the GUI thread is writing and the executor
thread is reading. (The native UpdateAdditionalMetadata function loops
through m_cached_files, which is unsafe if another thread is adding
elements to m_cached_files simultaneously.)

Losing out on this optimization isn't too bad, because
719930bb39 makes it very unlikely that
both threads will want the lock at the same time.

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/services/GameFileCacheManager.java

@@ -227,11 +227,9 @@ public final class GameFileCacheManager
     {
       String[] gamePaths = GameFileCache.getAllGamePaths();
 
-      boolean changed;
       synchronized (sGameFileCache)
       {
-        changed = sGameFileCache.update(gamePaths);
+        boolean changed = sGameFileCache.update(gamePaths);
-      }
         if (changed)
         {
           updateGameFileArray();
@@ -248,6 +246,7 @@ public final class GameFileCacheManager
           sGameFileCache.save();
         }
       }
+    }
 
     sRescanInProgress.postValue(false);
   }

Source/CMakeLists.txt

@@ -13,8 +13,6 @@ if(CMAKE_SYSTEM_NAME MATCHES "Windows")
   add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
   add_definitions(-D_CRT_NONSTDC_NO_WARNINGS)
   add_definitions(-D_SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING)
-  # The replacement for the old atomic shared_ptr functions was added in C++20, so we can't use it yet
-  add_definitions(-D_SILENCE_CXX20_OLD_SHARED_PTR_ATOMIC_SUPPORT_DEPRECATION_WARNING)
 endif()
 
 if (NOT MSVC)

Source/Core/UICommon/GameFileCache.cpp

@@ -4,7 +4,6 @@
 #include "UICommon/GameFileCache.h"
 
 #include <algorithm>
-#include <atomic>
 #include <cstddef>
 #include <functional>
 #include <list>
@@ -204,7 +203,7 @@ bool GameFileCache::UpdateAdditionalMetadata(std::shared_ptr<GameFile>* game_fil
   if (custom_cover_changed)
     copy->CustomCoverCommit();
 
-  std::atomic_store(game_file, std::move(copy));
+  *game_file = std::move(copy);
 
   return true;
 }

Source/VSProps/Base.Dolphin.props

@@ -29,8 +29,6 @@
       <PreprocessorDefinitions>_WINSOCK_DEPRECATED_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <!--Currently needed for some code in StringUtil used only on Android-->
       <PreprocessorDefinitions>_SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING;%(PreprocessorDefinitions)</PreprocessorDefinitions>
-      <!--The replacement for the old atomic shared_ptr functions was added in C++20, so we can't use it yet-->
-      <PreprocessorDefinitions>_SILENCE_CXX20_OLD_SHARED_PTR_ATOMIC_SUPPORT_DEPRECATION_WARNING;%(PreprocessorDefinitions)</PreprocessorDefinitions>
 
       <!--Dolphin-specific definitions-->
       <PreprocessorDefinitions Condition="'$(Platform)'=='x64'">_ARCH_64=1;_M_X86=1;_M_X86_64=1;%(PreprocessorDefinitions)</PreprocessorDefinitions>