Win32 thread priority isolation layer

other changes merged in this commit:
Update RageSoundReader_ThreadedBuffer.h
Update GameLoop.cpp
Update CMakeData-os.cmake

src/CMakeData-os.cmake

@@ -57,6 +57,7 @@ else()
                 "archutils/Win32/RegistryAccess.cpp"
                 "archutils/Win32/RestartProgram.cpp"
                 "archutils/Win32/SpecialDirs.cpp"
+                "archutils/Win32/ThreadPriorityHelper.cpp"
                 "archutils/Win32/USB.cpp"
                 "archutils/Win32/VideoDriverInfo.cpp"
                 "archutils/Win32/WindowIcon.cpp"
@@ -82,6 +83,7 @@ else()
                 "archutils/Win32/RegistryAccess.h"
                 "archutils/Win32/RestartProgram.h"
                 "archutils/Win32/SpecialDirs.h"
+                "archutils/Win32/ThreadPriorityHelper.h"
                 "archutils/Win32/USB.h"
                 "archutils/Win32/VideoDriverInfo.h"
                 "archutils/Win32/WindowIcon.h"

src/GameLoop.cpp

@@ -24,6 +24,9 @@
 #include <cmath>
 #include <vector>
 
+#ifdef _WIN32
+#include "archutils/Win32/ThreadPriorityHelper.h"
+#endif
 
 static RageTimer g_GameplayTimer;
 
@@ -410,6 +413,13 @@ void ConcurrentRenderer::RenderThread()
 
 		if( m_State == RENDERING_START )
 		{
+#ifdef _WIN32
+			bool setThreadSuccess = BoostThreadPriorityToHighest();
+			if (!setThreadSuccess)
+			{
+				ASSERT_M(0, "Failed to set thread priority to highest.");
+			}
+#endif
 			/* We're starting to render. Set up, and then kick the event to wake
 			 * up the calling thread. */
 			DISPLAY->BeginConcurrentRendering();

src/RageSoundReader_ThreadedBuffer.h

@@ -8,6 +8,10 @@
 #include "RageThreads.h"
 #include <list>
 
+#ifdef _WIN32
+#include "archutils/Win32/ThreadPriorityHelper.h"
+#endif
+
 class RageThread;
 class RageSoundReader_ThreadedBuffer: public RageSoundReader_Filter
 {
@@ -70,7 +74,19 @@ private:
 
 	RageThread m_Thread;
 	bool m_bShutdownThread;
-	static int StartBufferingThread( void *p ) { ((RageSoundReader_ThreadedBuffer *) p)->BufferingThread(); return 0; }
+	static int StartBufferingThread(void* p)
+	{
+#ifdef _WIN32
+		bool setThreadSuccess = BoostThreadPriorityToHighest();
+		if (!setThreadSuccess)
+		{
+			ASSERT_M(0, "Failed to set thread priority to highest.");
+		}
+#endif
+		((RageSoundReader_ThreadedBuffer*)p)->BufferingThread();
+		return 0;
+	}
+
 	void BufferingThread();
 };
 

src/archutils/Win32/ThreadPriorityHelper.cpp

@@ -0,0 +1,33 @@
+#include "ThreadPriorityHelper.h"
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+bool SetThreadPriorityLevel(int priorityLevel)
+{
+	return SetThreadPriority(GetCurrentThread(), priorityLevel) != 0;
+}
+
+bool BoostThreadPriorityToBelowNormal()
+{
+	return SetThreadPriorityLevel(THREAD_PRIORITY_BELOW_NORMAL);
+}
+
+bool BoostThreadPriorityToNormal()
+{
+	return SetThreadPriorityLevel(THREAD_PRIORITY_NORMAL);
+}
+
+bool BoostThreadPriorityToAboveNormal()
+{
+	return SetThreadPriorityLevel(THREAD_PRIORITY_ABOVE_NORMAL);
+}
+
+bool BoostThreadPriorityToHighest()
+{
+	return SetThreadPriorityLevel(THREAD_PRIORITY_HIGHEST);
+}
+
+bool BoostThreadPriorityToTimeCritical()
+{
+	return SetThreadPriorityLevel(THREAD_PRIORITY_TIME_CRITICAL);
+}

src/archutils/Win32/ThreadPriorityHelper.h

@@ -0,0 +1,70 @@
+/*++
+
+A layer to isolate windows.h from other source files while retaining the ability to set thread priorities.
+
+	One possible way to call it if you don't need to store the result is like so:
+
+		#ifdef _WIN32
+				bool SuccessStatus = BoostThreadPriorityToHighest();
+				if (!SuccessStatus)
+				{
+					ASSERT_M(0, "Failed to set thread priority to highest.");
+				}
+		#endif
+
+Please refer to the Windows SetThreadPriority function documentation for more information.
+https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-setthreadpriority
+
+Please maintain this priority structure for the threads:
+
+Highest or Time Critical
+* Rendering thread
+* Audio mixing thread
+	- If this is not high enough priority, it can negatively affect the game clock
+
+Above Normal or Highest
+* Audio decoding thread
+* Audio streaming thread
+* Audio buffering thread
+
+Normal
+* Main game thread
+	- Please keep this below the audio thread priority
+
+Below Normal
+* Worker threads
+
+--*/
+
+bool SetThreadPriorityLevel(int priorityLevel);
+
+bool BoostThreadPriorityToBelowNormal();
+bool BoostThreadPriorityToNormal();
+bool BoostThreadPriorityToAboveNormal();
+bool BoostThreadPriorityToHighest();
+bool BoostThreadPriorityToTimeCritical();
+
+/**
+ * (c) sukibaby 2024
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, and/or sell copies of the Software, and to permit persons to
+ * whom the Software is furnished to do so, provided that the above
+ * copyright notice(s) and this permission notice appear in all copies of
+ * the Software and that both the above copyright notice(s) and this
+ * permission notice appear in supporting documentation.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
+ * THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
+ * INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
+ * OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */