Port the async thread to a SDL timer

SDL implements timers via threads and it lets us easily aim at
a 60Hz frequency.

neo/framework/Common.cpp

@@ -26,6 +26,8 @@ If you have questions concerning this license or the applicable additional terms
 ===========================================================================
 */
 
+#include <SDL.h>
+
 #include "sys/platform.h"
 #include "idlib/containers/HashTable.h"
 #include "idlib/LangDict.h"
@@ -218,12 +220,13 @@ private:
 #ifdef ID_WRITE_VERSION
 	idCompressor *				config_compressor;
 #endif
+
+	SDL_TimerID					async_timer;
 };
 
 idCommonLocal	commonLocal;
 idCommon *		common = &commonLocal;
 
-
 /*
 ==================
 idCommonLocal::idCommonLocal
@@ -248,6 +251,8 @@ idCommonLocal::idCommonLocal( void ) {
 #ifdef ID_WRITE_VERSION
 	config_compressor = NULL;
 #endif
+
+	async_timer = NULL;
 }
 
 /*
@@ -2777,12 +2782,31 @@ void idCommonLocal::SetMachineSpec( void ) {
 	com_videoRam.SetInteger( vidRam );
 }
 
+static unsigned int async_tick;
+
+static unsigned int AsyncTimer(unsigned int interval, void *) {
+	common->Async();
+	Sys_TriggerEvent(TRIGGER_EVENT_ONE);
+	async_tick++;
+
+	// calculate the next interval to get as close to 60fps as possible
+	unsigned int now = SDL_GetTicks();
+	unsigned int tick = async_tick * 1000 / 60;
+
+	if (now >= tick)
+		return 1;
+
+	return tick - now;
+}
+
 /*
 =================
 idCommonLocal::Init
 =================
 */
 void idCommonLocal::Init( int argc, char **argv ) {
+	SDL_Init(SDL_INIT_TIMER);
+
 	Sys_InitThreads();
 
 	try {
@@ -2879,6 +2903,12 @@ void idCommonLocal::Init( int argc, char **argv ) {
 	catch( idException & ) {
 		Sys_Error( "Error during initialization" );
 	}
+
+	async_tick = (SDL_GetTicks() >> 4) + 1;
+	async_timer = SDL_AddTimer(16, AsyncTimer, NULL);
+
+	if (!async_timer)
+		Sys_Error("Error while starting the async timer");
 }
 
 
@@ -2888,9 +2918,13 @@ idCommonLocal::Shutdown
 =================
 */
 void idCommonLocal::Shutdown( void ) {
-
 	com_shuttingDown = true;
 
+	if (async_timer) {
+		SDL_RemoveTimer(async_timer);
+		async_timer = NULL;
+	}
+
 	idAsyncNetwork::server.Kill();
 	idAsyncNetwork::client.Shutdown();
 

neo/sys/linux/main.cpp

@@ -59,66 +59,6 @@ void Sys_InitScanTable( void ) {
 	common->DPrintf( "TODO: Sys_InitScanTable\n" );
 }
 
-/*
-=================
-Sys_AsyncThread
-=================
-*/
-THREAD_RETURN_TYPE Sys_AsyncThread( void * ) {
-	int now;
-	int next;
-	int	want_sleep;
-
-	// multi tick compensate for poor schedulers (Linux 2.4)
-	int ticked, to_ticked;
-	now = Sys_Milliseconds();
-	ticked = now >> 4;
-	while (1) {
-		// sleep
-		now = Sys_Milliseconds();
-		next = ( now & 0xFFFFFFF0 ) + 0x10;
-		want_sleep = ( next-now-1 ) * 1000;
-		if ( want_sleep > 0 ) {
-			usleep( want_sleep ); // sleep 1ms less than true target
-		}
-
-		// compensate if we slept too long
-		now = Sys_Milliseconds();
-		to_ticked = now >> 4;
-
-		// show ticking statistics - every 100 ticks, print a summary
-		#if 0
-			#define STAT_BUF 100
-			static int stats[STAT_BUF];
-			static int counter = 0;
-			// how many ticks to play
-			stats[counter] = to_ticked - ticked;
-			counter++;
-			if (counter == STAT_BUF) {
-				Sys_DebugPrintf("\n");
-				for( int i = 0; i < STAT_BUF; i++) {
-					if ( ! (i & 0xf) ) {
-						Sys_DebugPrintf("\n");
-					}
-					Sys_DebugPrintf( "%d ", stats[i] );
-				}
-				Sys_DebugPrintf("\n");
-				counter = 0;
-			}
-		#endif
-
-		while ( ticked < to_ticked ) {
-			common->Async();
-			ticked++;
-			Sys_TriggerEvent( TRIGGER_EVENT_ONE );
-		}
-		// thread exit
-		pthread_testcancel();
-	}
-
-	return (THREAD_RETURN_TYPE) 0;
-}
-
 /*
  ==============
  Sys_DefaultSavePath

neo/sys/osx/DOOMController.mm

@@ -978,23 +978,6 @@ static OSErr DoRegCodeDialog( char* ioRegCode1 )
 	return regCodeInfo.okPressed ? (OSErr)noErr : (OSErr)userCanceledErr;
 }
 
-/*
-=================
-Sys_AsyncThread
-=================
-*/
-THREAD_RETURN_TYPE Sys_AsyncThread( void * ) {
-	while ( 1 ) {
-		usleep( 16666 );
-		common->Async();
-		Sys_TriggerEvent( TRIGGER_EVENT_ONE );
-		pthread_testcancel();
-	}
-
-	return (THREAD_RETURN_TYPE) 0;
-}
-
-
 #if defined(__ppc__)
 
 /*

neo/sys/posix/posix_main.cpp

@@ -90,9 +90,7 @@ void Posix_Exit(int ret) {
 	}
 	// at this point, too late to catch signals
 	Posix_ClearSigs();
-	if ( asyncThread.threadHandle ) {
-		Sys_DestroyThread( asyncThread );
-	}
+
 	// process spawning. it's best when it happens after everything has shut down
 	if ( exit_spawn[0] ) {
 		Sys_DoStartProcess( exit_spawn, false );
@@ -542,7 +540,6 @@ Posix_EarlyInit
 ===============
 */
 void Posix_EarlyInit( void ) {
-	memset( &asyncThread, 0, sizeof( asyncThread ) );
 	exit_spawn[0] = '\0';
 	Posix_InitSigs();
 	// set the base time
@@ -563,7 +560,6 @@ void Posix_LateInit( void ) {
 #ifndef ID_DEDICATED
 	common->Printf( "%d MB Video Memory\n", Sys_GetVideoRam() );
 #endif
-	Posix_StartAsyncThread( );
 }
 
 /*

neo/sys/posix/posix_public.h

@@ -49,9 +49,6 @@ void		Posix_Exit( int ret );
 void		Posix_SetExit(int ret); // override the exit code
 void		Posix_SetExitSpawn( const char *exeName ); // set the process to be spawned when we quit
 
-void		Posix_StartAsyncThread( void );
-extern xthreadInfo asyncThread;
-
 bool		Posix_AddKeyboardPollEvent( int key, bool state );
 bool		Posix_AddMousePollEvent( int action, int value );
 
@@ -62,6 +59,4 @@ void		Posix_Shutdown( void );
 void		Sys_FPE_handler( int signum, siginfo_t *info, void *context );
 void		Sys_DoStartProcess( const char *exeName, bool dofork = true ); // if not forking, current process gets replaced
 
-THREAD_RETURN_TYPE	Sys_AsyncThread( void * );
-
 #endif

neo/sys/posix/posix_threads.cpp

@@ -139,28 +139,6 @@ const char* Sys_GetThreadName( int *index ) {
 	return "main";
 }
 
-/*
-=========================================================
-Async Thread
-=========================================================
-*/
-
-xthreadInfo asyncThread;
-
-/*
-=================
-Posix_StartAsyncThread
-=================
-*/
-void Posix_StartAsyncThread() {
-	if ( asyncThread.threadHandle == 0 ) {
-		Sys_CreateThread( Sys_AsyncThread, NULL, THREAD_NORMAL, asyncThread, "Async", g_threads, &g_thread_count );
-	} else {
-		common->Printf( "Async thread already running\n" );
-	}
-	common->Printf( "Async thread started\n" );
-}
-
 /*
 ==================
 Posix_InitPThreads

neo/sys/win32/win_main.cpp

@@ -819,76 +819,6 @@ void Sys_In_Restart_f( const idCmdArgs &args ) {
 	Sys_InitInput();
 }
 
-
-/*
-==================
-Sys_AsyncThread
-==================
-*/
-static THREAD_RETURN_TYPE Sys_AsyncThread( void *parm ) {
-	int		wakeNumber;
-	int		startTime;
-
-	startTime = Sys_Milliseconds();
-	wakeNumber = 0;
-
-	while ( 1 ) {
-#ifdef WIN32
-		// this will trigger 60 times a second
-		int r = WaitForSingleObject( hTimer, 100 );
-		if ( r != WAIT_OBJECT_0 ) {
-			OutputDebugString( "idPacketServer::PacketServerInterrupt: bad wait return" );
-		}
-#endif
-
-#if 0
-		wakeNumber++;
-		int		msec = Sys_Milliseconds();
-		int		deltaTime = msec - startTime;
-		startTime = msec;
-
-		char	str[1024];
-		sprintf( str, "%i ", deltaTime );
-		OutputDebugString( str );
-#endif
-
-
-		common->Async();
-	}
-
-	return (THREAD_RETURN_TYPE) 0;
-}
-
-/*
-==============
-Sys_StartAsyncThread
-
-Start the thread that will call idCommon::Async()
-==============
-*/
-void Sys_StartAsyncThread( void ) {
-	// create an auto-reset event that happens 60 times a second
-	hTimer = CreateWaitableTimer( NULL, false, NULL );
-	if ( !hTimer ) {
-		common->Error( "idPacketServer::Spawn: CreateWaitableTimer failed" );
-	}
-
-	LARGE_INTEGER	t;
-	t.HighPart = t.LowPart = 0;
-	SetWaitableTimer( hTimer, &t, USERCMD_MSEC, NULL, NULL, TRUE );
-
-	Sys_CreateThread( Sys_AsyncThread, NULL, THREAD_ABOVE_NORMAL, threadInfo, "Async", g_threads,  &g_thread_count );
-
-#ifdef SET_THREAD_AFFINITY
-	// give the async thread an affinity for the second cpu
-	SetThreadAffinityMask( (HANDLE)threadInfo.threadHandle, 2 );
-#endif
-
-	if ( !threadInfo.threadHandle ) {
-		common->Error( "Sys_StartAsyncThread: failed" );
-	}
-}
-
 /*
 ================
 Sys_AlreadyRunning
@@ -1212,8 +1142,6 @@ int main(int argc, char *argv[]) {
 	}
 #endif
 
-	Sys_StartAsyncThread();
-
 	// hide or show the early console as necessary
 	if ( win32.win_viewlog.GetInteger() || com_skipRenderer.GetBool() || idAsyncNetwork::serverDedicated.GetInteger() ) {
 		Sys_ShowConsole( 1, true );