From d72cacbdd49fe19ea903cd01477acdf31ca04448 Mon Sep 17 00:00:00 2001
From: ramapcsx2 <ramapcsx2@a6443dda-0b58-4228-96e9-037be469359c>
Date: Sat, 25 Oct 2008 13:37:48 +0000
Subject: [PATCH] Changed the Sleep() behavior as posted by Jake.Stine in Issue
 29. Improves smoothness in games running fullspeed, and lets pcsx2 use the
 cpu time it needs :)

(Note: You'll see constantly 100% cpu usage now, but pcsx2 doesn't do any "more" work.)

git-svn-id: http://pcsx2-playground.googlecode.com/svn/trunk@237 a6443dda-0b58-4228-96e9-037be469359c
---
 pcsx2/Counters.c        |  2 +-
 pcsx2/FiFo.c            |  6 +-----
 pcsx2/GS.cpp            | 41 +++++++++--------------------------------
 pcsx2/Misc.h            | 10 ++++++++++
 pcsx2/windows/WinMain.c | 13 +++++++++++--
 5 files changed, 32 insertions(+), 40 deletions(-)

diff --git a/pcsx2/Counters.c b/pcsx2/Counters.c
index ad769e6992..17015a360a 100644
--- a/pcsx2/Counters.c
+++ b/pcsx2/Counters.c
@@ -175,7 +175,7 @@ void FrameLimiter()
 		if ((diff>>3)>iTicks) iExpectedEnd=iEnd;
 	}
 	else do {
-		Sleep(1);
+		_TIMESLICE();
 		iEnd = GetCPUTicks();
 	} while (iEnd<iExpectedEnd);
 
diff --git a/pcsx2/FiFo.c b/pcsx2/FiFo.c
index 0714469925..8771863fc4 100644
--- a/pcsx2/FiFo.c
+++ b/pcsx2/FiFo.c
@@ -162,11 +162,7 @@ void WriteFIFO(u32 mem, u64 *value) {
 		//commiting every 16 bytes
 		while( FIFOto_write((void*)value, 1) == 0 ) {
 			SysPrintf("IPU sleeping\n");
-#ifdef _WIN32
-			Sleep(1);
-#else
-			usleep(500);
-#endif
+			_TIMESLICE();
 		}
 	} else {
 		SysPrintf("WriteFIFO Unknown %x\n", mem);
diff --git a/pcsx2/GS.cpp b/pcsx2/GS.cpp
index f60f40262a..f8e1b3ec93 100644
--- a/pcsx2/GS.cpp
+++ b/pcsx2/GS.cpp
@@ -230,11 +230,7 @@ void gsWaitGS()
     }
     else {
 	    while( g_pGSRingPos != g_pGSWritePos ) {
-#ifdef _WIN32
-		    Sleep(1);
-#else
-		    usleep(500);
-#endif
+			_TIMESLICE();
 	    }
     }
 }
@@ -305,11 +301,7 @@ u8* GSRingBufCopy(void* mem, u32 size, u32 type)
 		while( writepos < tempbuf || tempbuf == GS_RINGBUFFERBASE ) {
 			if( !CHECK_DUALCORE ) {
 				GS_SETEVENT();
-#ifdef _WIN32
-				Sleep(1);
-#else
-				usleep(500);
-#endif
+				_TIMESLICE();
 			}
 			tempbuf = *(volatile PU8*)&g_pGSRingPos;
 
@@ -329,11 +321,7 @@ u8* GSRingBufCopy(void* mem, u32 size, u32 type)
         while(tempbuf == GS_RINGBUFFERBASE && tempbuf != *(volatile PU8*)&g_pGSWritePos) {
             if( !CHECK_DUALCORE ) {
 				GS_SETEVENT();
-#ifdef _WIN32
-				Sleep(1);
-#else
-				usleep(500);
-#endif
+				_TIMESLICE();
 			}
 
             tempbuf = *(volatile PU8*)&g_pGSRingPos;
@@ -343,11 +331,7 @@ u8* GSRingBufCopy(void* mem, u32 size, u32 type)
 	while( writepos < tempbuf && (writepos+size >= tempbuf || (writepos+size == GS_RINGBUFFEREND && tempbuf == GS_RINGBUFFERBASE)) ) {
 		if( !CHECK_DUALCORE ) {
 			GS_SETEVENT();
-#ifdef _WIN32
-			Sleep(1);
-#else
-			usleep(500);
-#endif
+			_TIMESLICE();
 		}
 		tempbuf = *(volatile PU8*)&g_pGSRingPos;
 
@@ -373,11 +357,7 @@ void GSRingBufSimplePacket(int type, int data0, int data1, int data2)
 		do {
 			if( !CHECK_DUALCORE ) {
 				GS_SETEVENT();
-#ifdef _WIN32
-				Sleep(1);
-#else
-				usleep(500);
-#endif
+				_TIMESLICE();
 			}
 			tempbuf = *(volatile PU8*)&g_pGSRingPos;
 
@@ -397,11 +377,7 @@ void GSRingBufSimplePacket(int type, int data0, int data1, int data2)
         while(tempbuf == GS_RINGBUFFERBASE && tempbuf != *(volatile PU8*)&g_pGSWritePos) {
             if( !CHECK_DUALCORE ) {
 				GS_SETEVENT();
-#ifdef _WIN32
-				Sleep(1);
-#else
-				usleep(500);
-#endif
+				_TIMESLICE();
 			}
 
             tempbuf = *(volatile PU8*)&g_pGSRingPos;
@@ -1471,6 +1447,7 @@ int HasToExit()
 }
 
 #if defined(_WIN32) && !defined(WIN32_PTHREADS)
+//#pragma optimize ("",off) //needed for a working PGO build
 DWORD WINAPI GSThreadProc(LPVOID lpParam)
 {
 	HANDLE handles[2] = { g_hGsEvent, g_hVuGSExit };
@@ -1744,7 +1721,7 @@ ExitGS:
 	GSclose();
 	return 0;
 }
-
+//#pragma optimize ("",on) //needed for a working PGO build
 int gsFreeze(gzFile f, int Mode) {
 
 	gzfreeze(PS2MEM_GS, 0x2000);
@@ -1836,4 +1813,4 @@ void RunGSState(gzFile f)
 
 #endif
 
-#undef GIFchain
\ No newline at end of file
+#undef GIFchain
diff --git a/pcsx2/Misc.h b/pcsx2/Misc.h
index 53425ad126..7660806d21 100644
--- a/pcsx2/Misc.h
+++ b/pcsx2/Misc.h
@@ -363,5 +363,15 @@ extern __forceinline long InterlockedExchangeAdd(long volatile* Addend, long Val
 //#define InterlockedExchangePointerAdd InterlockedExchangeAdd
 //#endif
 
+// Timeslice releaser for those many idle loop spots through out PCSX2.
+static __forceinline void _TIMESLICE()
+{
+#ifdef _WIN32
+	    Sleep(0);
+#else
+	    usleep(500);
+#endif
+}
+
 #endif /* __MISC_H__ */
 
diff --git a/pcsx2/windows/WinMain.c b/pcsx2/windows/WinMain.c
index d62558d76b..d5744cbda8 100644
--- a/pcsx2/windows/WinMain.c
+++ b/pcsx2/windows/WinMain.c
@@ -140,7 +140,16 @@ void RunExecute(int run) {
 	if( GSsetGameCRC != NULL )
 		GSsetGameCRC(ElfCRC, g_ZeroGSOptions);
 
-	if (run) Cpu->Execute();
+	if (run)
+	{
+		// This makes sure the Windows Kernel is using high resolution
+		// timeslices for Sleep calls.
+		// (may not make much difference on most desktops but
+		//  can improve performance a lot on laptops).
+		timeBeginPeriod( 1 );
+		Cpu->Execute();
+		timeEndPeriod( 1 );
+	}
 }
 
 int Slots[5] = { -1, -1, -1, -1, -1 };
@@ -419,7 +428,7 @@ BOOL SysLoggedSetLockPagesPrivilege ( HANDLE hProcess, BOOL bEnable);
 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
 	char *lang;
 	int i;
-	
+
 #ifdef PCSX2_VIRTUAL_MEM
 	LPVOID lpMemReserved;
 #endif