Function SV_Frame

code/server/sv_main.cpp:431–527

*/
extern cvar_t	*cl_newClock;
void SV_Frame( int msec,float fractionMsec ) {
	int		frameMsec;
	int		startTime=0;

	// the menu kills the server with this cvar
	if ( sv_killserver->integer ) {
		SV_Shutdown ("Server was killed.\n");
		Cvar_Set( "sv_killserver", "0" );
		return;
	}

	if ( !com_sv_running->integer ) {
		return;
	}

 	extern void SE_CheckForLanguageUpdates(void);
	SE_CheckForLanguageUpdates();	// will fast-return else load different language if menu changed it

	// allow pause if only the local client is connected
	if ( SV_CheckPaused() ) {
		return;
	}

	// go ahead and let time slip if the server really hitched badly
	if ( msec > 1000 ) {
		Com_DPrintf( "SV_Frame: Truncating msec of %i to 1000\n", msec );
		msec = 1000;
	}

	// if it isn't time for the next frame, do nothing
	if ( sv_fps->integer < 1 ) {
		Cvar_Set( "sv_fps", "10" );
	}
	frameMsec = 1000 / sv_fps->integer ;

	sv.timeResidual += msec;
	sv.timeResidualFraction+=fractionMsec;
	if (sv.timeResidualFraction>=1.0f)
	{
		sv.timeResidualFraction-=1.0f;
		if (cl_newClock&&cl_newClock->integer)
		{
			sv.timeResidual++;
		}
	}
	if ( sv.timeResidual < frameMsec ) {
		return;
	}

	// if time is about to hit the 32nd bit, restart the
	// level, which will force the time back to zero, rather
	// than checking for negative time wraparound everywhere.
	// 2giga-milliseconds = 23 days, so it won't be too often
	if ( sv.time > 0x70000000 ) {
		SV_Shutdown( "Restarting server due to time wrapping" );
		Com_Printf("You win.  if you can play this long and not die, you deserve to win.\n");
		return;
	}