* improved getting the retrace semaphore, now the PrivateScreen

will not try to retrieve the retrace semaphore again and again
  if the graphics cards doesn't support it for some reason
* disabled BScreen::WaitForRetarce() for now, since it will just
  hang on ATI Radeon at least


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@17266 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/interface/PrivateScreen.cpp

@@ -213,12 +213,19 @@ BPrivateScreen::GetNextID(screen_id& id)
 status_t
 BPrivateScreen::WaitForRetrace(bigtime_t timeout)
 {
+// TODO: remove when interrupts are enabled again in the ATI driver
+return B_ERROR;
 	// Get the retrace semaphore if it's the first time 
 	// we are called. Cache the value then.
-	status_t status;
+	if (!fRetraceSemValid)
-	if (fRetraceSem < 0)
 		fRetraceSem = _RetraceSemaphore();
 
+	if (fRetraceSem < 0) {
+		// syncing to retrace is not supported by the accelerant
+		return fRetraceSem;
+	}
+
+	status_t status;
 	do {
 		status = acquire_sem_etc(fRetraceSem, 1, B_RELATIVE_TIMEOUT, timeout);
 	} while (status == B_INTERRUPTED);
@@ -633,7 +640,11 @@ BPrivateScreen::_RetraceSemaphore()
 	link.Attach<screen_id>(ID());
 
 	sem_id id = B_BAD_SEM_ID;
-	link.FlushWithReply(id); 
+	status_t status = B_ERROR;
+	if (link.FlushWithReply(status) == B_OK && status == B_OK) {
+		link.Read<sem_id>(&id);
+		fRetraceSemValid = true;
+	}
 
 	return id;
 }
@@ -661,6 +672,7 @@ BPrivateScreen::BPrivateScreen(screen_id id)
 	fID(id),
 	fColorMap(NULL),
 	fRetraceSem(-1),
+	fRetraceSemValid(false),
 	fOwnsColorMap(false),
 	fFrame(0, 0, 0, 0),
 	fLastUpdate(0)

src/kits/interface/PrivateScreen.h

@@ -89,6 +89,7 @@ class BPrivateScreen {
 		int32		fRefCount;
 		color_map*	fColorMap;
 		sem_id		fRetraceSem;
+		bool		fRetraceSemValid;
 		bool		fOwnsColorMap;
 		BRect		fFrame;
 		bigtime_t	fLastUpdate;

src/servers/app/ServerApp.cpp

@@ -2188,8 +2188,8 @@ ServerApp::_DispatchMessage(int32 code, BPrivate::LinkReceiver& link)
 			screen_id id;
 			link.Read<screen_id>(&id);
 
-			sem_id semaphore = fDesktop->HWInterface()->RetraceSemaphore();
+			fLink.StartMessage(B_OK);
-			fLink.StartMessage(semaphore);
+			fLink.Attach<sem_id>(fDesktop->HWInterface()->RetraceSemaphore());
 			fLink.Flush();
 			break;
 		}