Removed continuity_break code, added tiny DCQ switch

The continuity_break code is rendered superfluous by the FlushGraphics and
RenderingCond pair now, and it was breaking the situation where you try to
push onto a full queue.


git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@403 8092fc87-c524-0410-9efc-e669fe64eaf9

sc2/BUGS

@@ -101,7 +101,3 @@ The bugs reported but not yet verified:
 
 - In starmap, when any zone of influence is moving, the starmap cursor behaves badly 
   (erases what it passes over). Leaving and returning to the starmap fixes it
-
-- Under FreeBSD, waiting on condition variables doesn't seem to
-  actually wait or hand control to the renderer, thus spinlocking and
-  crashing.

sc2/ChangeLog

@@ -1,4 +1,8 @@
 0.2:
+- Defining DCQ_OF_DOOM lowers the DrawCommandQueue size to 512, to aid in
+  simulating severe overload stresses on the machine
+- Removed TFB_FlushGraphics' dependency on GraphicsSem, which the new
+  condition variable code both breaks and makes unnecessary
 - Scan tint is now cleared right after the scan, from PhracturedBlue
 - Recoded the DCQ to not sit on the heap, added debugging info
 - Fixed Outfit Starship and Shipyard graphics, from TDuck

sc2/src/sc2code/libs/graphics/sdl/3do_funcs.c

@@ -77,7 +77,6 @@ FlushGraphics (void)
 {
 	TFB_DrawCommand DrawCommand;
 	TFB_BatchReset ();
-	continuity_break = 1;
 	DrawCommand.Type = TFB_DRAWCOMMANDTYPE_FLUSHGRAPHICS;
 	DrawCommand.image = 0;
 	TFB_EnqueueDrawCommand(&DrawCommand);

sc2/src/sc2code/libs/graphics/sdl/dcqueue.c

@@ -32,7 +32,11 @@ static Uint32 DCQ_locking_thread = 0;
 // become tolerable before initiating livelock deterrence and game
 // slowdown.  Other constants for controlling the frameskip/slowdown
 // balance may be found in sdl_common.c near TFB_FlushGraphics.
+#ifdef DCQ_OF_DOOM
+#define DCQ_MAX 512
+#else
 #define DCQ_MAX 16384
+#endif
 TFB_DrawCommand DCQ[DCQ_MAX];
 
 TFB_DrawCommandQueue DrawCommandQueue;
@@ -151,16 +155,17 @@ TFB_DrawCommandQueue_Push (TFB_DrawCommand* Command)
 	while (DrawCommandQueue.FullSize >= DCQ_MAX - 1)
 	{
 		int old_depth, i;
-		fprintf (stderr, "DCQ overload (Size = %d).  Sleeping until renderer is done.\n", DrawCommandQueue.Size);
+		fprintf (stderr, "DCQ overload (Size = %d, FullSize = %d).  Sleeping until renderer is done.\n", DrawCommandQueue.Size, DrawCommandQueue.FullSize);
 		// Restore the DCQ locking level.  I *think* this is
 		// always 1, but...
+		TFB_BatchReset ();
 		old_depth = DCQ_locking_depth;
 		for (i = 0; i < old_depth; i++)
 			Unlock_DCQ ();
 		WaitCondVar (RenderingCond);
 		for (i = 0; i < old_depth; i++)
 			Lock_DCQ ();
-		fprintf (stderr, "DCQ clear (Size = %d).  Continuing.\n", DrawCommandQueue.Size);
+		fprintf (stderr, "DCQ clear (Size = %d, FullSize = %d).  Continuing.\n", DrawCommandQueue.Size, DrawCommandQueue.FullSize);
 	}
 	DCQ[DrawCommandQueue.InsertionPoint] = *Command;
 	DrawCommandQueue.InsertionPoint = (DrawCommandQueue.InsertionPoint + 1) % DCQ_MAX;

sc2/src/sc2code/libs/graphics/sdl/sdl_common.c

@@ -37,8 +37,6 @@ volatile int TransitionAmount = 255;
 SDL_Rect TransitionClipRect;
 
 int GfxFlags = 0;
-volatile int continuity_break;
-
 
 int
 TFB_InitGraphics (int driver, int flags, int width, int height, int bpp)
@@ -511,9 +509,15 @@ TFB_ComputeFPS ()
 // on slower machines.  Even there, it's seems nonexistent outside of
 // communications screens.  --Michael
 
+#ifdef DCQ_OF_DOOM
+#define DCQ_FORCE_SLOWDOWN_SIZE 128
+#define DCQ_FORCE_BREAK_SIZE 512
+#define DCQ_LIVELOCK_MAX 256
+#else
 #define DCQ_FORCE_SLOWDOWN_SIZE 1024
 #define DCQ_FORCE_BREAK_SIZE 4096
 #define DCQ_LIVELOCK_MAX 2048
+#endif
 
 void
 TFB_FlushGraphics () // Only call from main thread!!
@@ -548,23 +552,6 @@ TFB_FlushGraphics () // Only call from main thread!!
 		return;
 	}
 
-	if (!continuity_break) {
-		// TODO: a more optimal way of getting the lock on GraphicsSem..
-		//       cannot currently use SDL_SemWait because it would break
-		//       the usage of continuity_break
-		// Michael asks: Why are we locking, then releasing, the GraphicsSem?
-
-		semval = TimeoutSetSemaphore (GraphicsSem, ONE_SECOND / 10);
-		if (semval != 0)
-		{
-			BroadcastCondVar (RenderingCond);
-			return;
-		}
-		else
-			SDL_SemPost (GraphicsSem);
-	}
-	continuity_break = 0;
-
 	if (GfxFlags & TFB_GFXFLAGS_SHOWFPS)
 		TFB_ComputeFPS ();
 

sc2/src/sc2code/libs/graphics/sdl/sdl_common.h

@@ -36,7 +36,6 @@ extern SDL_Surface *TransitionScreen;
 extern volatile int TransitionAmount;
 extern SDL_Rect TransitionClipRect;
 
-extern volatile int continuity_break;
 extern int GfxFlags;
 
 void ScreenOrigin (FRAME Display, COORD sx, COORD sy);