reduced CPU usage in the client

changelog.txt

@@ -1,6 +1,8 @@
 
 DD Mmm 17 - 1.49
 
+chg: reduced CPU usage in the client
+
 add: console color customization cvars
   con_colBG     <RGBA> (default: "101013F6") - console and help panel background
   con_colBorder <RGBA> (default: "4778B2FF") - the console and help panel borders

code/client/cl_scrn.cpp

@@ -394,10 +394,16 @@ static void SCR_PerformanceCounters()
 void SCR_UpdateScreen()
 {
 	static int recursive = 0;
+	static int lastRenderTime = 0;
 
 	if ( !scr_initialized )
 		return;
 
+#ifndef DEDICATED
+	if ( !CL_VideoRecording() && Sys_IsMinimized() && Sys_Milliseconds() - lastRenderTime < 1000 )
+		return;
+#endif
+
 	// there are several cases where this IS called twice in one frame
 	// easiest example is: conn to a server, kill the server
 	if ( ++recursive > 2 ) {
@@ -427,5 +433,6 @@ void SCR_UpdateScreen()
 	}
 
 	recursive = 0;
+	lastRenderTime = Sys_Milliseconds();
 }
 

code/linux/linux_shared.cpp

@@ -40,6 +40,39 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
 #define MEM_THRESHOLD 96*1024*1024
 
+
+static void LIN_MicroSleep( int us )
+{
+	timespec req, rem;
+	req.tv_sec = us / 1000000;
+	req.tv_nsec = (us % 1000000) * 1000;
+	while (clock_nanosleep(CLOCK_REALTIME, 0, &req, &rem) == EINTR) {
+		req = rem;
+	}
+}
+
+
+void Sys_Sleep( int ms )
+{
+	LIN_MicroSleep(ms * 1000);
+}
+
+
+void Sys_MicroSleep( int us )
+{
+	LIN_MicroSleep(us);
+}
+
+
+int64_t Sys_Microseconds()
+{
+	timespec ts;
+	clock_gettime(CLOCK_REALTIME, &ts);
+
+	return (int64_t)ts.tv_sec * 1000000 + (int64_t)ts.tv_nsec / 1000;
+}
+
+
 qboolean Sys_LowPhysicalMemory()
 {
 	return qfalse; // FIXME

code/linux/sdl_core.cpp

@@ -595,3 +595,9 @@ void Sys_MatchAlert( sysMatchAlertEvent_t event )
 	else if (event == SMAE_MATCH_END)
 		Lin_MatchEndAlert();
 }
+
+
+qbool Sys_IsMinimized()
+{
+	return (glimp.window != NULL) && (SDL_GetWindowFlags(glimp.window) & SDL_WINDOW_MINIMIZED) != 0;
+}

code/qcommon/common.cpp

@@ -26,6 +26,10 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "common_help.h"
 #include <setjmp.h>
 
+#ifndef INT64_MIN
+#	define INT64_MIN 0x8000000000000000LL
+#endif
+
 #if (_MSC_VER >= 1400) // Visual C++ 2005 or later
 #define MSVC_CPUID 1
 #include <intrin.h>
@@ -2445,19 +2449,52 @@ void Com_Frame()
 		minMsec = 1000 / com_maxfps->integer;
 
 #ifndef DEDICATED
+	qbool preciseCap = qtrue;
 	// let's not limit the download speed by sleeping too much
 	qbool CL_MapDownload_Active(); // in client.h
 	if ( CL_MapDownload_Active() )
-		minMsec = 1;
+		minMsec = 4;
+	else if ( Sys_IsMinimized() ) {
+		minMsec = 20;
+		preciseCap = qfalse;
+	}
+#else
+	const qbool preciseCap = qfalse;
 #endif
 
+	// decide when we should stop sleeping
+	static int64_t targetTimeUS = INT64_MIN;
+	const int64_t frameDurationUS = 1000000 / com_maxfps->integer;
+	if ( Sys_Microseconds() > targetTimeUS + 3 * frameDurationUS )
+		targetTimeUS = Sys_Microseconds() + frameDurationUS;
+	else
+		targetTimeUS += frameDurationUS;
+
+	// sleep if needed
+	int runEventLoop = 0;
+	if ( preciseCap ) {
+		for ( ;; ) {
+			runEventLoop ^= 1;
+			const int64_t remainingUS = targetTimeUS - Sys_Microseconds();
+			if ( remainingUS > 3000 && runEventLoop )
+				Com_EventLoop();
+			else if ( remainingUS > 1000 )
+				Sys_Sleep( 1 );
+			else if ( remainingUS > 50 )
+				Sys_MicroSleep( 50 );
+			else
+				break;
+		}
+	} else {
+		while ( targetTimeUS - Sys_Microseconds() > 1000 ) {
+			Sys_Sleep(1);
+		}
+	}
+
 	static int lastTime = 0;
-	int msec;
-	do {
-		com_frameTime = Com_EventLoop();
-		msec = com_frameTime - lastTime;
-	} while ( msec < minMsec );
 	lastTime = com_frameTime;
+	com_frameTime = Com_EventLoop();
+	int msec = com_frameTime - lastTime;
 
 	Cbuf_Execute();
 

code/qcommon/qcommon.h

@@ -1122,6 +1122,14 @@ int		Sys_GetUptimeSeconds( qbool parent );	// negative if not available
 void	Sys_LoadHistory();
 void	Sys_SaveHistory();
 
+void	Sys_Sleep( int ms );
+void	Sys_MicroSleep( int us );
+int64_t	Sys_Microseconds();
+
+#ifndef DEDICATED
+qbool	Sys_IsMinimized();
+#endif
+
 // huffman.cpp - id's original code
 // used for out-of-band (OOB) datagrams with dynamically created trees
 void	DynHuff_Compress( msg_t* buf, int offset );

code/win32/win_glimp.cpp

@@ -697,6 +697,12 @@ void Sys_GL_Shutdown()
 }
 
 
+qbool Sys_IsMinimized()
+{
+	return ( g_wv.hWnd != NULL ) && !!IsIconic( g_wv.hWnd );
+}
+
+
 void WIN_UpdateResolution( int width, int height )
 {
 	glInfo.winWidth = width;

code/win32/win_shared.cpp

@@ -36,6 +36,50 @@ int Sys_Milliseconds()
 }
 
 
+void Sys_Sleep( int ms )
+{
+	if (ms >= 1)
+		Sleep(ms);
+}
+
+void Sys_MicroSleep( int us )
+{
+	if (us <= 0)
+		return;
+
+	LARGE_INTEGER frequency;
+	LARGE_INTEGER endTime;
+	QueryPerformanceCounter(&endTime);
+	QueryPerformanceFrequency(&frequency);
+	endTime.QuadPart += ((LONGLONG)us * frequency.QuadPart) / 1000000LL;
+
+	LARGE_INTEGER currentTime;
+	do {
+		SwitchToThread();
+		QueryPerformanceCounter(&currentTime);
+	} while (currentTime.QuadPart < endTime.QuadPart);
+}
+
+
+int64_t Sys_Microseconds()
+{
+	static qbool initialized = qfalse;
+	static LARGE_INTEGER start;
+	static LARGE_INTEGER freq;
+
+	if (!initialized) {
+		initialized = qtrue;
+		QueryPerformanceFrequency(&freq);
+		QueryPerformanceCounter(&start);
+	}
+
+	LARGE_INTEGER now;
+	QueryPerformanceCounter(&now);
+
+	return ((now.QuadPart - start.QuadPart) * 1000000LL) / freq.QuadPart;
+}
+
+
 const char* Sys_DefaultHomePath()
 {
 	return NULL;