From dda669080ce79eea40a9c8447e0fd4e4bbd84288 Mon Sep 17 00:00:00 2001
From: mcmartin <mcmartin@8092fc87-c524-0410-9efc-e669fe64eaf9>
Date: Thu, 12 Dec 2002 23:00:33 +0000
Subject: [PATCH] Some race conditions eliminated, from PhracturedBlue Also
 added debug information.

git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@417 8092fc87-c524-0410-9efc-e669fe64eaf9
---
 sc2/ChangeLog                            |  1 +
 sc2/src/sc2code/libs/threads/thrcommon.c | 73 ++++++++++++++++++++++--
 sc2/src/sc2code/outfit.c                 |  5 +-
 sc2/src/sc2code/restart.c                |  2 +
 sc2/src/sc2code/shipyard.c               |  3 +-
 5 files changed, 78 insertions(+), 6 deletions(-)

diff --git a/sc2/ChangeLog b/sc2/ChangeLog
index 08ed36311..c372e23fc 100644
--- a/sc2/ChangeLog
+++ b/sc2/ChangeLog
@@ -1,4 +1,5 @@
 0.2:
+- Some race conditions eliminated, from PhracturedBlue
 - Earth / other slave shielded planet color issue fixed, from PhracturedBlue
 - Orbit/starmap related lockup fixed, from PhracturedBlue
 - 3D planet showing on starmap when in orbit fixed, from PhracturedBlue
diff --git a/sc2/src/sc2code/libs/threads/thrcommon.c b/sc2/src/sc2code/libs/threads/thrcommon.c
index b4710e072..4ea7a82e1 100644
--- a/sc2/src/sc2code/libs/threads/thrcommon.c
+++ b/sc2/src/sc2code/libs/threads/thrcommon.c
@@ -27,11 +27,22 @@
 #include <unistd.h>
 #endif
 
+#define DEBUG_TRACK_SEM
+
+#ifdef DEBUG_TRACK_SEM
+// Define all semaphores to be tracked in SemList.  Make sure it is NULL terminated
+// Make that  semthread is the same length  as SemList, and is initialized as all 0's
+extern Semaphore GraphicsSem;
+static Semaphore *SemList[] = {&GraphicsSem, NULL};
+Uint32 semthread[] = {0, 0};
+#endif
+
 #ifdef THREAD_QUEUE
 static volatile Thread threadQueue = NULL;
 static Semaphore threadQueueSemaphore;
 #endif
 
+
 struct ThreadStartInfo
 {
 	ThreadFunction func;
@@ -307,25 +318,79 @@ DestroySemaphore (Semaphore sem)
 int
 SetSemaphore (Semaphore sem)
 {
-	return NativeSetSemaphore ((NativeSemaphore) sem);
+	int i;
+
+	i = NativeSetSemaphore ((NativeSemaphore) sem);
+#ifdef DEBUG_TRACK_SEM
+	if (i != 0)
+		fprintf(stderr, "WARNING: SetSemaphore did not return 0, this could be bad!\n");
+	for (i = 0; SemList[i] != NULL; i++)
+		if (*SemList[i] == sem)
+		{
+			semthread[i] = SDL_ThreadID ();
+			break;
+		}
+#endif
+	return i;
 }
 
 int
 TrySetSemaphore (Semaphore sem)
 {
-	return NativeTrySetSemaphore ((NativeSemaphore) sem);
+	int i;
+
+	i = NativeTrySetSemaphore ((NativeSemaphore) sem);
+#ifdef DEBUG_TRACK_SEM
+	if (i == 0)
+		for (i = 0; SemList[i] != NULL; i++)
+			if (*SemList[i] == sem)
+			{
+				semthread[i] = SDL_ThreadID ();
+				break;
+			}
+#endif
+	return (i);
 }
 
 int
 TimeoutSetSemaphore (Semaphore sem, TimePeriod timeout)
 {
-	return NativeTimeoutSetSemaphore ((NativeSemaphore) sem,
-			timeout);
+	int i;
+
+	i = NativeTimeoutSetSemaphore ((NativeSemaphore) sem, timeout);
+#ifdef DEBUG_TRACK_SEM
+	if (i == 0)
+		for (i = 0; SemList[i] != NULL; i++)
+			if (*SemList[i] == sem)
+			{
+				semthread[i] = SDL_ThreadID ();
+				break;
+			}
+#endif
+	return (i);
 }
 
 void
 ClearSemaphore (Semaphore sem)
 {
+	int i;
+#ifdef DEBUG_TRACK_SEM
+	Uint32 semval = SDL_SemValue (sem);
+	if (semval != 0)
+	{
+		fprintf (stderr, "WARNING: trying to clear a free semaphore (value=%d)\n", semval);
+		// Should we unset the Semaphore twice?  Perhaps not.
+		return;
+	}
+	for (i = 0;SemList[i] != NULL; i++)
+		if (*SemList[i] == sem)
+		{
+			if (! semthread[i] && semthread[i] != SDL_ThreadID ())
+				fprintf( stderr, "WARNING: tried to free a Semaphore held by another thread!\n");
+			semthread[i] = 0;
+			break;
+		}
+#endif
 	NativeClearSemaphore ((NativeSemaphore) sem);
 }
 
diff --git a/sc2/src/sc2code/outfit.c b/sc2/src/sc2code/outfit.c
index 611dae0f8..87521a9f4 100644
--- a/sc2/src/sc2code/outfit.c
+++ b/sc2/src/sc2code/outfit.c
@@ -539,6 +539,7 @@ DoOutfit (INPUT_STATE InputState, PMENU_STATE pMS)
 
 			BatchGraphics ();
 			DrawSISFrame ();
+			SetSemaphore(GraphicsSem);
 			DrawSISMessage (GAME_STRING (STARBASE_STRING_BASE + 2));
 			DrawSISTitle (GAME_STRING (STARBASE_STRING_BASE));
 
@@ -572,7 +573,6 @@ DoOutfit (INPUT_STATE InputState, PMENU_STATE pMS)
 						GLOBAL_SIS (ModuleSlots[num_frames])) < EMPTY_SLOT)
 					DrawShipPiece (pMS, which_piece, num_frames, FALSE);
 			}
-
 			RedistributeFuel ();
 			DisplayLanders (pMS);
 			if (GET_GAME_STATE (CHMMR_BOMB_STATE) < 3)
@@ -596,8 +596,11 @@ DoOutfit (INPUT_STATE InputState, PMENU_STATE pMS)
 					DrawStamp ((PSTAMP)&s);
 			}
 
+			ClearSemaphore(GraphicsSem);
 			DrawMenuStateStrings (PM_FUEL, pMS->CurState);
+			SetSemaphore(GraphicsSem);
 			DrawFlagshipName (FALSE);
+			ClearSemaphore(GraphicsSem);
 
 {
 	RECT r;
diff --git a/sc2/src/sc2code/restart.c b/sc2/src/sc2code/restart.c
index c5df5f37e..de8aa7592 100644
--- a/sc2/src/sc2code/restart.c
+++ b/sc2/src/sc2code/restart.c
@@ -220,7 +220,9 @@ LastActivity = WON_LAST_BATTLE;
 			BatchGraphics ();
 			ClearDrawable ();
 			FlushColorXForms ();
+			SetSemaphore (GraphicsSem);
 			DrawStamp (&s);
+			ClearSemaphore (GraphicsSem);
 			UnbatchGraphics ();
 
 			FlushInput ();
diff --git a/sc2/src/sc2code/shipyard.c b/sc2/src/sc2code/shipyard.c
index 1f1acb015..5075da352 100644
--- a/sc2/src/sc2code/shipyard.c
+++ b/sc2/src/sc2code/shipyard.c
@@ -1070,9 +1070,10 @@ DoShipyard (INPUT_STATE InputState, PMENU_STATE pMS)
 			BatchGraphics ();
 
 			DrawSISFrame ();
+			SetSemaphore(GraphicsSem);
 			DrawSISMessage (GAME_STRING (STARBASE_STRING_BASE + 3));
 			DrawSISTitle (GAME_STRING (STARBASE_STRING_BASE));
-
+			ClearSemaphore(GraphicsSem);
 			DrawBluePrint (pMS);
 			pMS->ModuleFrame = s.frame;