FlushGraphics now tracks and wakes each thread individually, lessening

the stuttering when multiple threads are performing Flush operations.

Also, a number of comments have been reworked for accuracy.


git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@527 8092fc87-c524-0410-9efc-e669fe64eaf9

sc2/ChangeLog

@@ -1,4 +1,5 @@
 Changes towards version 0.2:
+- FlushGraphics now waits and notifies on a per-thread level
 - No longer using SHGetFolderPath on Windows - SvdB
 - Key repeat is now enabled when typing text, from slayne
 - Capital letter bug in new input code fixed, from slayne

sc2/TODO

@@ -78,10 +78,6 @@ Implementation bugs (low priority):
 - 3D planet view when entering orbit is now done, but there's some things
   which could make it look nicer, like better slave shield and removing 
   occasional pops/discontinuities
-  - Rotation and zooming isn't now as smooth as before after condition
-    variable DCQ patch
-    - This is because of the fact that all FlushGraphics routines wait on
-      one lone condition variable -- we need one per thread, effectively.
 - Transitions (crossfades) aren't perhaps correctly done always, syncing
   might be wrong etc.
   - Condition variable DCQ patch should have fixed this.  Confirm?

sc2/src/msvc++/UrQuanMasters.dsp

@@ -651,6 +651,10 @@ SOURCE=..\sc2code\libs\threads\thrcommon.c
 
 SOURCE=..\sc2code\libs\threads\thrcommon.h
 # End Source File
+# Begin Source File
+
+SOURCE=..\sc2code\libs\threads\condbank.c
+# End Source File
 # End Group
 # Begin Group "time"
 

sc2/src/sc2code/libs/graphics/gfx_common.h

@@ -109,6 +109,7 @@ typedef struct tfb_drawcommand
 	BOOLEAN UsePalette;
 	int BlendNumerator;
 	int BlendDenominator;
+	DWORD thread;
 } TFB_DrawCommand;
 
 // Queue Stuff

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

@@ -54,12 +54,10 @@ UninitGraphics ()  // Also probably empty
 }
 
 
-// Batch/UnbatchGraphics: These routines appear to be used to ensure
-// that the screen doesn't update with a half-drawn region.  This can
-// be implemented in all sorts of ways - I've chosen to fold it into
-// our DrawCommandQueue, for the most part.  These just forward to
-// the TFB_ versions in dcqueue.c.  They may also make continuity_break
-// redundant, but I haven't tested that yet.  --Michael
+/* Batching and Unbatching functions.  A "Batch" is a collection of
+   DrawCommands that will never be flipped to the screen half-rendered.
+   BatchGraphics and UnbatchGraphics function vaguely like a non-blocking
+   recursive lock to do this respect. */
 void
 BatchGraphics (void)
 {
@@ -72,6 +70,9 @@ UnbatchGraphics (void)
 	TFB_UnbatchGraphics ();
 }
 
+/* Sleeps this thread until all Draw Commands queued by that thread have
+   been processed. */
+
 void
 FlushGraphics (void)
 {
@@ -80,7 +81,7 @@ FlushGraphics (void)
 	DrawCommand.Type = TFB_DRAWCOMMANDTYPE_FLUSHGRAPHICS;
 	DrawCommand.image = 0;
 	TFB_EnqueueDrawCommand(&DrawCommand);
-	WaitCondVar (RenderingCond);
+	WaitForSignal ();
 }
 
 void

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

@@ -224,6 +224,7 @@ TFB_EnqueueDrawCommand (TFB_DrawCommand* DrawCommand)
 		return;
 	}
 
+	DrawCommand->thread = CurrentThreadID ();
 	if (DrawCommand->Type <= TFB_DRAWCOMMANDTYPE_COPYFROMOTHERBUFFER
 			&& TYPE_GET (_CurFramePtr->TypeIndexAndFlags) == SCREEN_DRAWABLE)
 	{

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

@@ -737,7 +737,8 @@ TFB_FlushGraphics () // Only call from main thread!!
 			break;
 		case TFB_DRAWCOMMANDTYPE_FLUSHGRAPHICS:
 			// done = TRUE;			
-			TFB_SwapBuffers ();
+			// TFB_SwapBuffers ();
+			SignalThread (DC.thread);
 			break;
 		case TFB_DRAWCOMMANDTYPE_SKIPGRAPHICS:
 			TFB_DrawCommandQueue_Clear ();

sc2/src/sc2code/libs/threadlib.h

@@ -65,7 +65,8 @@
 
 extern void InitThreadSystem (void);
 extern void UnInitThreadSystem (void);
-
+extern void init_cond_bank (void);
+extern void uninit_cond_bank (void);
 
 typedef int (*ThreadFunction) (void *);
 
@@ -130,5 +131,10 @@ extern void WaitCondVar (CondVar);
 extern void SignalCondVar (CondVar);
 extern void BroadcastCondVar (CondVar);
 
+extern DWORD CurrentThreadID (void);
+
+extern void WaitForSignal (void);
+extern void SignalThread (DWORD);
+
 #endif  /* _THREADLIB_H */
 

sc2/src/sc2code/libs/threads/Makeinfo

@@ -1,2 +1,2 @@
 uqm_SUBDIRS="sdl"
-uqm_CFILES="thrcommon.c"
+uqm_CFILES="condbank.c thrcommon.c"

sc2/src/sc2code/libs/threads/condbank.c

@@ -0,0 +1,110 @@
+//Copyright Paul Reiche, Fred Ford. 1992-2002
+
+/*
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/* This defines the Condition Variable Bank.  Individual threads may
+   sleep until they are signaled by their Thread ID.  If the Condition 
+   Variable Bank is exhausted (unlikely!) it will wait on the DCQ's 
+   condition variable.  This may produce stuttering. */
+
+#include <stdio.h>
+#include "starcon.h"
+#include "libs/threadlib.h"
+
+/* The Condition Variable Bank. */
+
+#define CONDVAR_BANK_SIZE 10
+
+static Semaphore bank_sem;
+
+static struct {
+	CondVar var;
+	DWORD   id;
+	int     used;
+} bank[CONDVAR_BANK_SIZE];
+
+void
+init_cond_bank ()
+{
+	int i;
+	bank_sem = CreateSemaphore (1, "CondVar Bank Semaphore");
+	for (i = 0; i < CONDVAR_BANK_SIZE; i++)
+	{
+		bank[i].var = CreateCondVar ();
+		bank[i].id = bank[i].used = 0;
+	}
+}
+
+void
+uninit_cond_bank ()
+{
+	int i;
+	for (i = 0; i < CONDVAR_BANK_SIZE; i++)
+	{
+		DestroyCondVar (bank[i].var);
+	}
+	DestroySemaphore (bank_sem);
+}
+
+void
+WaitForSignal ()
+{
+	int i;
+	int index = -1;
+	DWORD me = CurrentThreadID ();
+	SetSemaphore (bank_sem);
+	for (i = 0; i < CONDVAR_BANK_SIZE; i++)
+	{
+		if (!bank[i].used)
+		{
+			index = i;
+			break;
+		}
+	}
+	if (index == -1)
+	{
+		/* The bank is full! */
+		fprintf(stderr, "Condvar bank is full, %ul is waiting on DCQ.", me);
+		ClearSemaphore (bank_sem);
+		WaitCondVar (RenderingCond);
+	}
+	else
+	{
+		bank[i].used = 1;
+		bank[i].id = me;
+		ClearSemaphore (bank_sem);
+		WaitCondVar (bank[i].var);
+	}
+}
+
+void
+SignalThread (DWORD id)
+{
+	int i;
+	SetSemaphore (bank_sem);
+	for (i = 0; i < CONDVAR_BANK_SIZE; i++)
+	{
+		if (bank[i].used && bank[i].id == id)
+		{
+			bank[i].id = bank[i].used = 0;
+			SignalCondVar (bank[i].var);
+			break;
+		}
+	}
+	ClearSemaphore (bank_sem);
+}
+

sc2/src/sc2code/libs/threads/sdl/sdlthreads.h

@@ -86,14 +86,16 @@ typedef SDL_cond *NativeCondVar;
 #define NativeCreateCondVar() \
 		SDL_CreateCond ()
 #define NativeDestroyCondVar(condvar) \
-		SDL_DestroyCond((condvar))
+		SDL_DestroyCond ((condvar))
 #define NativeWaitCondVar(condvar) \
-		SDLWrapper_WaitCondVar((condvar))
+		SDLWrapper_WaitCondVar ((condvar))
 #define NativeSignalCondVar(condvar) \
-		SDL_CondSignal((condvar))
+		SDL_CondSignal ((condvar))
 #define NativeBroadcastCondVar(condvar) \
-		SDL_CondBroadcast((condvar))
+		SDL_CondBroadcast ((condvar))
 
+#define NativeCurrentThreadID() \
+		SDL_ThreadID ()
 
 #endif  /* _SDLTHREAD_H */
 

sc2/src/sc2code/libs/threads/thrcommon.c

@@ -89,11 +89,13 @@ InitThreadSystem (void)
 	signal(SIGUSR1, SigUSR1Handler);
 #endif
 	NativeInitThreadSystem ();
+	init_cond_bank ();
 }
 
 void
 UnInitThreadSystem (void)
 {
+	uninit_cond_bank ();
 	NativeUnInitThreadSystem ();
 #ifdef PROFILE_THREADS
 	signal(SIGUSR1, SIG_DFL);
@@ -602,3 +604,8 @@ void BroadcastCondVar (CondVar cv)
 {
 	NativeBroadcastCondVar (cv);
 }
+
+DWORD CurrentThreadID ()
+{
+	return (DWORD)NativeThreadID ();
+}