From 9a27f3d44b1e630569eaf294aada5c4a91c1edf4 Mon Sep 17 00:00:00 2001
From: Jamie Reece Wilson <me@reece.sx>
Date: Sun, 9 Jul 2023 13:51:05 +0100
Subject: [PATCH] [*] Lower idle CPU usage (idle utilization regression)

---
 Include/Aurora/Runtime.hpp    |  1 +
 Source/AuProcAddresses.NT.cpp | 28 +++++++++++++++++++++++-----
 Source/AuProcAddresses.NT.hpp |  1 +
 Source/AuRTEntrypoint.cpp     |  9 +++++++--
 4 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/Include/Aurora/Runtime.hpp b/Include/Aurora/Runtime.hpp
index 3ff62b58..f7648fad 100644
--- a/Include/Aurora/Runtime.hpp
+++ b/Include/Aurora/Runtime.hpp
@@ -351,6 +351,7 @@ namespace Aurora
         AuUInt8 uSpinLoopPowerA { 7 };                   // Nudgable spinloop power. This is our local userland niceness factor; where 1 << n is the amount of yield instructions to stall for
         
         bool bEnableAggressiveScheduling      { false };
+        bool bEnableAgrSchedulingRatelimit    { true };
         bool bPreferNt51XpMutexesOver8        { false }; // Fun Fact: Undocumented Windows XP APIs are still better than whatever the fuck shit fest they sharted out under Windows Vista and maybe 8.1
         bool bPerferNt51XpCondvarsOver8       { false }; // Wth the former set of apis, we are still nothing more than a futex intended for nothing more than x86 bittestandset with undefined
     };                                                   // bahviour on the higher bits, and we're crippled by some annoying thread switch function. Windows Vista superseded the dumb kernel-io
diff --git a/Source/AuProcAddresses.NT.cpp b/Source/AuProcAddresses.NT.cpp
index dcc0fb22..33ee3e1c 100644
--- a/Source/AuProcAddresses.NT.cpp
+++ b/Source/AuProcAddresses.NT.cpp
@@ -9,6 +9,8 @@
 
 namespace Aurora
 {
+    static bool gShouldResPathDoNothing {};
+
     void InitNTAddresses()
     {
     #if defined(AURORA_PLATFORM_WIN32)
@@ -121,23 +123,39 @@ namespace Aurora
                               !pNtWaitForKeyedEvent;
 
         gUseNativeWaitCondvar = (pWaitOnAddress &&
-                                !gRuntimeConfig.threadingConfig.bPerferNt51XpCondvarsOver8 &&
-                                (pRtlWaitOnAddress || AuBuild::kCurrentPlatform != AuBuild::EPlatform::ePlatformWin32)) ||
-                               !pNtWaitForKeyedEvent;
+                                 !gRuntimeConfig.threadingConfig.bPerferNt51XpCondvarsOver8 &&
+                                 (pRtlWaitOnAddress || AuBuild::kCurrentPlatform != AuBuild::EPlatform::ePlatformWin32)) ||
+                                !pNtWaitForKeyedEvent;
 
         gUseNativeWaitSemapahore = bool(pWaitOnAddress);
     }
 
+    void Win32DropInit()
+    {
+        gShouldResPathDoNothing = 
+            (AuBuild::kCurrentPlatform != AuBuild::EPlatform::ePlatformWin32) ||
+            (!gRuntimeConfig.threadingConfig.bEnableAggressiveScheduling &&
+            AuSwInfo::IsWindows10OrGreater());
+    }
+
     void Win32DropSchedulerResolution()
     {
+        static AuUInt uCounter {};
         ULONG ullActualResolution {};
 
-        if (!gRuntimeConfig.threadingConfig.bEnableAggressiveScheduling &&
-            AuSwInfo::IsWindows10OrGreater())
+        if (gShouldResPathDoNothing)
         {
             return;
         }
 
+        if (gRuntimeConfig.threadingConfig.bEnableAgrSchedulingRatelimit)
+        {
+            if (!((uCounter++) & 128))
+            {
+                return;
+            }
+        }
+
         if (pZwSetTimerResolution)
         {
             auto uRet = pZwSetTimerResolution(1, true, &ullActualResolution);
diff --git a/Source/AuProcAddresses.NT.hpp b/Source/AuProcAddresses.NT.hpp
index 25ae75e2..c4c9a850 100644
--- a/Source/AuProcAddresses.NT.hpp
+++ b/Source/AuProcAddresses.NT.hpp
@@ -200,5 +200,6 @@ namespace Aurora
     inline bool gUseNativeWaitCondvar {};
     inline bool gUseNativeWaitSemapahore {};
 
+    void Win32DropInit();
     void Win32DropSchedulerResolution();
 }
\ No newline at end of file
diff --git a/Source/AuRTEntrypoint.cpp b/Source/AuRTEntrypoint.cpp
index 05ab03fe..961da1db 100644
--- a/Source/AuRTEntrypoint.cpp
+++ b/Source/AuRTEntrypoint.cpp
@@ -58,9 +58,8 @@ static void Init()
 
     gRuntimeRunLevel = 1;
     tlsHackIsMainThread = true;
-#if defined(AURORA_PLATFORM_WIN32)
-    Aurora::Win32DropSchedulerResolution();
 
+#if defined(AURORA_PLATFORM_WIN32)
     Aurora::Extensions::Win32::InitDarkMode();
 #endif
 
@@ -73,6 +72,12 @@ static void Init()
     Aurora::Threading::InitSleep();
     Aurora::Process::InitProcess();
     Aurora::SWInfo::InitSwInfo();
+
+#if defined(AURORA_PLATFORM_WIN32)
+    Aurora::Win32DropInit();
+    Aurora::Win32DropSchedulerResolution();
+#endif
+
     Aurora::Threading::Threads::InitThreading();
     Aurora::Exit::InitExit();
     Aurora::IO::Net::InitNetworking();