Fix for some redraw issues on Tk-Cocoa on OS X 10.11; further refinement of memory management; thanks to Marc Culler for patches

14 files changed, 227 insertions, 151 deletions

diff --git a/macosx/README b/macosx/README
index 69be037..202dbbd 100644
--- a/macosx/README
+++ b/macosx/README
@@ -388,3 +388,64 @@ make overrides to the tk/macosx GNUmakefile, e.g.
 	sudo make -C tk${ver}/macosx install \
 	    TCL_FRAMEWORK_DIR=$HOME/Library/Frameworks TCLSH_DIR=$HOME/usr/bin
 The Makefile variables TCL_FRAMEWORK_DIR and TCLSH_DIR were added with Tk 8.4.3.
+
+4. About the event loop in Tk for Mac OSX
+-----------------------------------------
+
+The main program in a typical OSX application looks like this (see *)
+
+    void NSApplicationMain(int argc, char *argv[]) {
+        [NSApplication sharedApplication];
+        [NSBundle loadNibNamed:@"myMain" owner:NSApp];
+        [NSApp run];
+    }
+
+The run method implements the event loop for the application.  There
+are three key steps in the run method.  First it calls 
+[NSApp finishLaunching], which creates the bouncing application icon
+and does other mysterious things. Second it creates an
+NSAutoreleasePool.  Third, it starts an event loop which drains the
+NSAutoreleasePool every time the queue is empty, and replaces the
+drained pool with a new one.  This third step is essential to
+preventing memory leaks, since the internal methods of Appkit objects
+all assume that an autorelease pool is in scope and will be drained
+when the event processing cycle ends.
+
+Mac OSX Tk does not call the [NSApp run] method at all.  Instead it
+uses the event loop built in to Tk.  So we must take care to replicate
+the important features of the method ourselves.  Here is how this
+works in outline.
+
+We add a private NSAUtoreleasePool* property to our subclass of
+NSApplication.  (The subclass is called TKApplication but can be
+referenced with the global variable NSApp).  The TkpInit
+function calls [NSApp _setup] which initializes this property by
+creating an NSAutoreleasePool. A bit later on, TkpInit calls
+[NSAPP _setupEventLoop] which in turn calls the
+[NSApp finishLaunching] method.
+
+Each time that Tcl processes an event in its queue, it calls a
+platform specific function which, in the case of Mac OSX, is named
+TkMacOSXEventsCheckProc.  In the unix implementations of Tk, including
+the Mac OSX version, this function collects events from an "event
+source", and transfers them to the Tcl event queue.  In Mac OSX the
+event source is the NSApplication event queue.  Each NSEvent is
+converted to a Tcl event which is added to the Tcl event queue.  The
+NSEvent is also passed to [NSApp sendevent], which sends the event on
+to the application's NSWindows, which send it to their NSViews, etc.
+Since the CheckProc function gets called for every Tk event, it is an
+appropriate place to drain the main NSAutoreleasePool and replace it
+with a new pool.  This is done by calling the method
+[NSApp _resetAutoreleasePool], where _resetAutoreleasePool is a method
+which we define for the subclass TKApplication.
+
+One minor caveat is that there are several steps of the Tk
+initialization which precede the call to TkpInit.  Notably, the font
+package is initialized first.  Since there is no NSAUtoreleasePool in
+scope prior to calling TkpInit, the functions called in these
+preliminary stages need to create and drain their own
+NSAutoreleasePools whenever they call methods of Appkit objects
+(e.g. NSFont).
+
+* https://developer.apple.com/library/mac/documentation/Cocoa/\
+Reference/ApplicationKit/Classes/NSApplication_Class
diff --git a/macosx/tkMacOSXDialog.c b/macosx/tkMacOSXDialog.c
index fb6e490..a3510f8 100644
--- a/macosx/tkMacOSXDialog.c
+++ b/macosx/tkMacOSXDialog.c
@@ -1733,9 +1733,7 @@ TkInitFontchooser(
     Tcl_SetAssocData(interp, "::tk::fontchooser", DeleteFontchooserData,
 	    fcdPtr);
     if (!fontPanelFontAttributes) {
-	NSAutoreleasePool *pool = [NSAutoreleasePool new];
 	fontPanelFontAttributes = [NSMutableDictionary new];
-	[pool drain];
     }
     return TCL_OK;
 }
diff --git a/macosx/tkMacOSXDraw.c b/macosx/tkMacOSXDraw.c
index 10f7b9e..6a0b409 100644
--- a/macosx/tkMacOSXDraw.c
+++ b/macosx/tkMacOSXDraw.c
@@ -138,7 +138,6 @@ BitmapRepFromDrawableRect(
     CGImageRef cg_image=NULL, sub_cg_image=NULL;
     NSBitmapImageRep *bitmap_rep=NULL;
     NSView *view=NULL;
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
     if ( mac_drawable->flags & TK_IS_PIXMAP ) {
 	/*
 	   This means that the MacDrawable is functioning as a Tk Pixmap, so its view
@@ -175,7 +174,6 @@ BitmapRepFromDrawableRect(
     } else {
 	TkMacOSXDbgMsg("Invalid source drawable");
     }
-    [pool drain];
     return bitmap_rep;
 }
 
@@ -1636,7 +1634,6 @@ TkMacOSXSetupDrawingContext(
     int dontDraw = 0, isWin = 0;
     TkMacOSXDrawingContext dc = {};
     CGRect clipBounds;
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
 
     dc.clipRgn = TkMacOSXGetClipRgn(d);
     if (!dontDraw) {
@@ -1767,7 +1764,6 @@ end:
 	dc.clipRgn = NULL;
     }
     *dcPtr = dc;
-    [pool drain];
     return !dontDraw;
 }
 
@@ -1791,7 +1787,6 @@ void
 TkMacOSXRestoreDrawingContext(
     TkMacOSXDrawingContext *dcPtr)
 {
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
     if (dcPtr->context) {
 	CGContextSynchronize(dcPtr->context);
 	[[dcPtr->view window] setViewsNeedDisplay:YES];
@@ -1808,7 +1803,6 @@ TkMacOSXRestoreDrawingContext(
 #ifdef TK_MAC_DEBUG
     bzero(dcPtr, sizeof(TkMacOSXDrawingContext));
 #endif /* TK_MAC_DEBUG */
-    [pool drain];
 }
 
 /*
@@ -1834,7 +1828,6 @@ TkMacOSXGetClipRgn(
 {
     MacDrawable *macDraw = (MacDrawable *) drawable;
     HIShapeRef clipRgn = NULL;
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
 
     if (macDraw->winPtr && macDraw->flags & TK_CLIP_INVALID) {
 	TkMacOSXUpdateClipRgn(macDraw->winPtr);
@@ -1860,7 +1853,6 @@ TkMacOSXGetClipRgn(
     } else if (macDraw->visRgn) {
 	clipRgn = HIShapeCreateCopy(macDraw->visRgn);
     }
-    [pool drain];
     return clipRgn;
 }
 
@@ -1913,7 +1905,6 @@ TkpClipDrawableToRect(
 {
     MacDrawable *macDraw = (MacDrawable *) d;
     NSView *view = TkMacOSXDrawableView(macDraw);
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
 
     if (macDraw->drawRgn) {
 	CFRelease(macDraw->drawRgn);
@@ -1947,7 +1938,6 @@ TkpClipDrawableToRect(
 	    macDraw->flags &= ~TK_FOCUSED_VIEW;
 	}
     }
-    [pool drain];
 }
 
 /*
diff --git a/macosx/tkMacOSXEvent.c b/macosx/tkMacOSXEvent.c
index db13249..7f3357f 100644
--- a/macosx/tkMacOSXEvent.c
+++ b/macosx/tkMacOSXEvent.c
@@ -128,10 +128,6 @@ enum {
 MODULE_SCOPE void
 TkMacOSXFlushWindows(void)
 {
-    /* This can be called from outside the Appkit event loop,
-     * so it needs its own AutoreleasePool.
-     */
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
     NSArray *macWindows = [NSApp orderedWindows];
 
     for (NSWindow *w in macWindows) {
@@ -139,7 +135,6 @@ TkMacOSXFlushWindows(void)
 	    [w flushWindow];
 	}
     }
-    [pool drain];
 }
 
 
diff --git a/macosx/tkMacOSXFont.c b/macosx/tkMacOSXFont.c
index 54b0fb8..c48e56e 100644
--- a/macosx/tkMacOSXFont.c
+++ b/macosx/tkMacOSXFont.c
@@ -210,6 +210,7 @@ FindNSFont(
 	nsFont = [fm convertFont:nsFont toSize:size];
 	nsFont = [fm convertFont:nsFont toHaveTrait:traits];
     }
+    [nsFont retain];
     #undef defaultFont
     return nsFont;
 }
@@ -306,7 +307,7 @@ InitFont(
 	    [NSNumber numberWithInt:fmPtr->fixed ? 0 : 1],
 		NSLigatureAttributeName,
 	    [NSNumber numberWithDouble:kern], NSKernAttributeName, nil];
-            fontPtr->nsAttributes = [nsAttributes retain];
+    fontPtr->nsAttributes = [nsAttributes retain];
     #undef nCh
 }
 
@@ -371,6 +372,7 @@ TkpFontPkgInit(
     NSFont *nsFont;
     TkFontAttributes fa;
     NSMutableCharacterSet *cs;
+    /* Since we called before TkpInit, we need our own autorelease pool. */
     NSAutoreleasePool *pool = [NSAutoreleasePool new];
 
     /* force this for now */
@@ -530,7 +532,7 @@ TkpGetFontFromAttributes(
 	nsFont = FindNSFont(faPtr->family, traits, weight, points, 1);
     }
     if (!nsFont) {
-	Tcl_Panic("Could not deternmine NSFont from TkFontAttributes");
+	Tcl_Panic("Could not determine NSFont from TkFontAttributes");
     }
     if (tkFontPtr == NULL) {
 	fontPtr = ckalloc(sizeof(MacFont));
@@ -675,7 +677,6 @@ TkpGetFontAttrsForChar(
 {
     MacFont *fontPtr = (MacFont *) tkfont;
     NSFont *nsFont = fontPtr->nsFont;
-
     *faPtr = fontPtr->font.fa;
     if (nsFont && ![[nsFont coveredCharacterSet] characterIsMember:c]) {
 	UTF16Char ch = c;
diff --git a/macosx/tkMacOSXInit.c b/macosx/tkMacOSXInit.c
index 98e6824..c658149 100644
--- a/macosx/tkMacOSXInit.c
+++ b/macosx/tkMacOSXInit.c
@@ -57,9 +57,19 @@ static void keyboardChanged(CFNotificationCenterRef center, void *observer, CFSt
 @end
 
 @implementation TKApplication
+#ifndef __clang__
+@synthesize poolProtected = _poolProtected;
+#endif
 @end
 
 @implementation TKApplication(TKInit)
+- (void) _resetAutoreleasePool
+{
+    if(![self poolProtected]) {
+	[_mainPool drain];
+	_mainPool = [NSAutoreleasePool new];
+    }
+}
 #ifdef TK_MAC_DEBUG_NOTIFICATIONS
 - (void) _postedNotification: (NSNotification *) notification
 {
@@ -86,16 +96,19 @@ static void keyboardChanged(CFNotificationCenterRef center, void *observer, CFSt
 
 - (void) _setupEventLoop
 {
-
-    /*Remove private API flags here.*/
+    NSAutoreleasePool *pool = [NSAutoreleasePool new];
     [self finishLaunching];
     [self setWindowsNeedUpdate:YES];
+    [pool drain];
 }
 
 - (void) _setup: (Tcl_Interp *) interp
 {
     _eventInterp = interp;
+    _mainPool = nil;
+    [NSApp setPoolProtected:NO];
     _defaultMainMenu = nil;
+    NSAutoreleasePool *pool = [NSAutoreleasePool new];
     [self _setupMenus];
     [self setDelegate:self];
 #ifdef TK_MAC_DEBUG_NOTIFICATIONS
@@ -104,12 +117,13 @@ static void keyboardChanged(CFNotificationCenterRef center, void *observer, CFSt
 #endif
     [self _setupWindowNotifications];
     [self _setupApplicationNotifications];
+    [pool drain];
 }
 
 - (NSString *) tkFrameworkImagePath: (NSString *) image
 {
     NSString *path = nil;
-
+    NSAutoreleasePool *pool = [NSAutoreleasePool new];
     if (tkLibPath[0] != '\0') {
 	path = [[NSBundle bundleWithPath:[[NSString stringWithUTF8String:
 		tkLibPath] stringByAppendingString:@"/../.."]]
@@ -142,6 +156,8 @@ static void keyboardChanged(CFNotificationCenterRef center, void *observer, CFSt
 	}
     }
 #endif
+    [path retain];
+    [pool drain];
     return path;
 }
 @end
@@ -168,6 +184,7 @@ static void
 SetApplicationIcon(
     ClientData clientData)
 {
+    NSAutoreleasePool *pool = [NSAutoreleasePool new];
     NSString *path = [NSApp tkFrameworkImagePath:@"Tk.icns"];
     if (path) {
 	NSImage *image = [[NSImage alloc] initWithContentsOfFile:path];
@@ -176,6 +193,7 @@ SetApplicationIcon(
 	    [image release];
 	}
     }
+    [pool drain];
 }
 
 /*
@@ -253,16 +271,19 @@ TkpInit(
 	}
 #endif
 
-	NSAutoreleasePool *pool = [NSAutoreleasePool new];
-	[[NSUserDefaults standardUserDefaults] registerDefaults:
-		[NSDictionary dictionaryWithObjectsAndKeys:
-		[NSNumber numberWithBool:YES],
-		@"_NSCanWrapButtonTitles",
-		[NSNumber numberWithInt:-1],
-		@"NSStringDrawingTypesetterBehavior",
-		nil]];
-	[TKApplication sharedApplication];
-	[NSApp _setup:interp];
+	{
+	    NSAutoreleasePool *pool = [NSAutoreleasePool new];
+		[[NSUserDefaults standardUserDefaults] registerDefaults:
+		     [NSDictionary dictionaryWithObjectsAndKeys:
+		     [NSNumber numberWithBool:YES],
+		     @"_NSCanWrapButtonTitles",
+		     [NSNumber numberWithInt:-1],
+		     @"NSStringDrawingTypesetterBehavior",
+		     nil]];
+	    [TKApplication sharedApplication];
+	    [pool drain];
+	    [NSApp _setup:interp];
+	}
 
 	/* Check whether we are a bundled executable: */
 	bundleRef = CFBundleGetMainBundle();
@@ -319,12 +340,15 @@ TkpInit(
 	    Tcl_DoWhenIdle(SetApplicationIcon, NULL);
 	}
 
-	[NSApp _setupEventLoop];
-	TkMacOSXInitAppleEvents(interp);
-	TkMacOSXUseAntialiasedText(interp, -1);
-	TkMacOSXInitCGDrawing(interp, TRUE, 0);
-	[pool drain];
-
+	{
+	    NSAutoreleasePool *pool = [NSAutoreleasePool new];
+	    [NSApp _setupEventLoop];
+	    TkMacOSXInitAppleEvents(interp);
+	    TkMacOSXUseAntialiasedText(interp, -1);
+	    TkMacOSXInitCGDrawing(interp, TRUE, 0);
+	    [pool drain];
+	}
+	
 	/*
 	 * FIXME: Close stdin & stdout for remote debugging otherwise we will
 	 * fight with gdb for stdin & stdout
@@ -480,9 +504,8 @@ TkpDisplayWarning(
 MODULE_SCOPE void
 TkMacOSXDefaultStartupScript(void)
 {
-    CFBundleRef bundleRef;
-
-    bundleRef = CFBundleGetMainBundle();
+    NSAutoreleasePool *pool = [NSAutoreleasePool new];
+    CFBundleRef bundleRef = CFBundleGetMainBundle();
 
     if (bundleRef != NULL) {
 	CFURLRef appMainURL = CFBundleCopyResourceURL(bundleRef,
@@ -506,6 +529,7 @@ TkMacOSXDefaultStartupScript(void)
 	    CFRelease(appMainURL);
 	}
     }
+    [pool drain];
 }
 
 /*
diff --git a/macosx/tkMacOSXKeyEvent.c b/macosx/tkMacOSXKeyEvent.c
index 8521beb..151b4f2 100644
--- a/macosx/tkMacOSXKeyEvent.c
+++ b/macosx/tkMacOSXKeyEvent.c
@@ -328,7 +328,7 @@ static unsigned isFunctionKey(unsigned int code);
   pt.y = caret_y;
 
   pt = [self convertPoint: pt toView: nil];
-  pt = [[self window] convertBaseToScreen: pt];
+  pt = [[self window] convertPointToScreen: pt];
   pt.y -= caret_height;
 
   rect.origin = pt;
diff --git a/macosx/tkMacOSXMenu.c b/macosx/tkMacOSXMenu.c
index 0c078ce..c7e3a78 100644
--- a/macosx/tkMacOSXMenu.c
+++ b/macosx/tkMacOSXMenu.c
@@ -258,10 +258,10 @@ static int	ModifierCharWidth(Tk_Font tkfont);
 
 	if (menuPtr && mePtr) {
 	    Tcl_Interp *interp = menuPtr->interp;
-	    /*Add time for errors to fire if necessary. This is sub-optimal but avoids issues with Tcl/Cocoa event loop integration.*/
+	    /*Add time for errors to fire if necessary. This is sub-optimal
+	     *but avoids issues with Tcl/Cocoa event loop integration.
+	     */
 	    Tcl_Sleep(100);
-
-	    NSAutoreleasePool *pool = [NSAutoreleasePool new];
 	    Tcl_Preserve(interp);
 	    Tcl_Preserve(menuPtr);
 
@@ -274,7 +274,6 @@ static int	ModifierCharWidth(Tk_Font tkfont);
 	    }
 	    Tcl_Release(menuPtr);
 	    Tcl_Release(interp);
-	    [pool drain];
 	}
     }
 }
@@ -377,13 +376,6 @@ static int	ModifierCharWidth(Tk_Font tkfont);
 
 @implementation TKApplication(TKMenu)
 
-- (void) safeSetMainMenu: (NSMenu *) menu
-{
-    NSAutoreleasePool* pool = [NSAutoreleasePool new];
-    [self setMainMenu: menu];
-    [pool drain];
-}
-
 - (void) menuBeginTracking: (NSNotification *) notification
 {
 #ifdef TK_MAC_DEBUG_NOTIFICATIONS
@@ -420,7 +412,7 @@ static int	ModifierCharWidth(Tk_Font tkfont);
 
 	    if (!mePtr || !(mePtr->entryFlags & ENTRY_APPLE_MENU)) {
 		applicationMenuItem = [NSMenuItem itemWithSubmenu:
-			[[_defaultApplicationMenu copy] autorelease]];
+			[_defaultApplicationMenu copy]];
 		[menu insertItem:applicationMenuItem atIndex:0];
 	    }
 	    [menu setSpecial:tkMainMenu];
@@ -428,7 +420,7 @@ static int	ModifierCharWidth(Tk_Font tkfont);
 	applicationMenu = (TKMenu *)[applicationMenuItem submenu];
 	if (![applicationMenu isSpecial:tkApplicationMenu]) {
 	    for (NSMenuItem *item in _defaultApplicationMenuItems) {
-		[applicationMenu addItem:[[item copy] autorelease]];
+		[applicationMenu addItem:[item copy]];
 	    }
 	    [applicationMenu setSpecial:tkApplicationMenu];
 	}
@@ -438,15 +430,13 @@ static int	ModifierCharWidth(Tk_Font tkfont);
 	for (NSMenuItem *item in itemArray) {
 	    TkMenuEntry *mePtr = (TkMenuEntry *)[item tag];
 	    TKMenu *submenu = (TKMenu *)[item submenu];
-
 	    if (mePtr && submenu) {
 		if ((mePtr->entryFlags & ENTRY_WINDOWS_MENU) &&
 			![submenu isSpecial:tkWindowsMenu]) {
 		    NSInteger index = 0;
 
 		    for (NSMenuItem *i in _defaultWindowsMenuItems) {
-			[submenu insertItem:[[i copy] autorelease] atIndex:
-				index++];
+			[submenu insertItem:[i copy] atIndex:index++];
 		    }
 		    [self setWindowsMenu:submenu];
 		    [submenu setSpecial:tkWindowsMenu];
@@ -455,8 +445,7 @@ static int	ModifierCharWidth(Tk_Font tkfont);
 		    NSInteger index = 0;
 
 		    for (NSMenuItem *i in _defaultHelpMenuItems) {
-			[submenu insertItem:[[i copy] autorelease] atIndex:
-				index++];
+			[submenu insertItem:[i copy] atIndex:index++];
 		    }
 		    [submenu setSpecial:tkHelpMenu];
 		}
@@ -475,7 +464,7 @@ static int	ModifierCharWidth(Tk_Font tkfont);
 	[servicesMenuItem setSubmenu:_servicesMenu];
     }
     [self setAppleMenu:applicationMenu];
-    [self safeSetMainMenu:menu];
+    [self setMainMenu:menu];
 }
 @end
 
diff --git a/macosx/tkMacOSXNotify.c b/macosx/tkMacOSXNotify.c
index 3fe59bd..06207e2 100644
--- a/macosx/tkMacOSXNotify.c
+++ b/macosx/tkMacOSXNotify.c
@@ -50,7 +50,7 @@ static void TkMacOSXEventsCheckProc(ClientData clientData, int flags);
 @end
 
 @implementation TKApplication(TKNotify)
-/* Call super then redisplay all of our windows. */
+/* Display all windows each time an event is removed from the queue.*/
 - (NSEvent *) nextEventMatchingMask: (NSUInteger) mask
 	untilDate: (NSDate *) expiration inMode: (NSString *) mode
 	dequeue: (BOOL) deqFlag
@@ -59,9 +59,9 @@ static void TkMacOSXEventsCheckProc(ClientData clientData, int flags);
 					untilDate:expiration
 					   inMode:mode
 					  dequeue:deqFlag];
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
+    /* Retain this event for later use. Must be released.*/
+    [event retain];
     [NSApp makeWindowsPerform:@selector(tkDisplayIfNeeded) inOrder:NO];
-    [pool drain];
     return event;
 }
 
@@ -70,10 +70,8 @@ static void TkMacOSXEventsCheckProc(ClientData clientData, int flags);
  */
 - (void) sendEvent: (NSEvent *) theEvent
 {
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
     [super sendEvent:theEvent];
     [NSApp tkCheckPasteboard];
-    [pool drain];
 }
 @end
 
@@ -217,19 +215,21 @@ TkMacOSXEventsSetupProc(
     ClientData clientData,
     int flags)
 {
-    if (flags & TCL_WINDOW_EVENTS &&
-	    ![[NSRunLoop currentRunLoop] currentMode]) {
+    NSString *runloopMode = [[NSRunLoop currentRunLoop] currentMode];
+    /* runloopMode will be nil if we are in the Tcl event loop. */
+    if (flags & TCL_WINDOW_EVENTS && !runloopMode) {
 	static const Tcl_Time zeroBlockTime = { 0, 0 };
-	NSAutoreleasePool *pool = [NSAutoreleasePool new];
 	/* Call this with dequeue=NO -- just checking if the queue is empty. */
 	NSEvent *currentEvent = [NSApp nextEventMatchingMask:NSAnyEventMask
-						   untilDate:[NSDate distantPast]
-						      inMode:GetRunLoopMode(TkMacOSXGetModalSession())
-						     dequeue:NO];
-	if (currentEvent && currentEvent.type > 0) {
-	    Tcl_SetMaxBlockTime(&zeroBlockTime);
+				       untilDate:[NSDate distantPast]
+				       inMode:GetRunLoopMode(TkMacOSXGetModalSession())
+				       dequeue:NO];
+	if (currentEvent) {
+	    if (currentEvent.type > 0) {
+		Tcl_SetMaxBlockTime(&zeroBlockTime);
+	    }
+	    [currentEvent release];
 	}
-	[pool drain];
     }
 }
 
@@ -256,13 +256,14 @@ TkMacOSXEventsCheckProc(
     int flags)
 {
     NSString *runloopMode = [[NSRunLoop currentRunLoop] currentMode];
+    /* runloopMode will be nil if we are in the Tcl event loop. */
     if (flags & TCL_WINDOW_EVENTS && !runloopMode) {
-
 	NSEvent *currentEvent = nil;
 	NSEvent *testEvent = nil;
 	NSModalSession modalSession;
-
+	
 	do {
+	    [NSApp _resetAutoreleasePool];
 	    modalSession = TkMacOSXGetModalSession();
 	    testEvent = [NSApp nextEventMatchingMask:NSAnyEventMask
 					      untilDate:[NSDate distantPast]
@@ -277,25 +278,25 @@ TkMacOSXEventsCheckProc(
 					      untilDate:[NSDate distantPast]
 						 inMode:GetRunLoopMode(modalSession)
 						dequeue:YES];
-	    if (!currentEvent) {
-		break; /* No events are available. */
-	    }
-	    NSAutoreleasePool *pool = [NSAutoreleasePool new];
-	    /* Generate Xevents. */
-	    int oldServiceMode = Tcl_SetServiceMode(TCL_SERVICE_ALL);
-	    NSEvent *processedEvent = [NSApp tkProcessEvent:currentEvent];
-	    Tcl_SetServiceMode(oldServiceMode);
-	    if (processedEvent) { /* Should always be non-NULL. */
+	    if (currentEvent) {
+		/* Generate Xevents. */
+		int oldServiceMode = Tcl_SetServiceMode(TCL_SERVICE_ALL);
+		NSEvent *processedEvent = [NSApp tkProcessEvent:currentEvent];
+		Tcl_SetServiceMode(oldServiceMode);
+		if (processedEvent) { /* Should always be non-NULL. */
 #ifdef TK_MAC_DEBUG_EVENTS
-		TKLog(@"   event: %@", currentEvent);
+		    TKLog(@"   event: %@", currentEvent);
 #endif
-		if (modalSession) {
-		    [NSApp _modalSession:modalSession sendEvent:currentEvent];
-		} else {
-		    [NSApp sendEvent:currentEvent];
+		    if (modalSession) {
+			[NSApp _modalSession:modalSession sendEvent:currentEvent];
+		    } else {
+			[NSApp sendEvent:currentEvent];
+		    }
 		}
+		[currentEvent release];
+	    } else {
+		break;
 	    }
-	    [pool drain];
 	} while (1);
     }
 }
diff --git a/macosx/tkMacOSXPrivate.h b/macosx/tkMacOSXPrivate.h
index 90d5a9b..2a411f6 100644
--- a/macosx/tkMacOSXPrivate.h
+++ b/macosx/tkMacOSXPrivate.h
@@ -275,10 +275,13 @@ VISIBILITY_HIDDEN
     NSArray *_defaultApplicationMenuItems, *_defaultWindowsMenuItems;
     NSArray *_defaultHelpMenuItems;
     NSWindow *_windowWithMouse;
+    NSAutoreleasePool *_mainPool;
 }
+@property BOOL poolProtected;
 @end
 @interface TKApplication(TKInit)
 - (NSString *)tkFrameworkImagePath:(NSString*)image;
+- (void)_resetAutoreleasePool;
 @end
 @interface TKApplication(TKEvent)
 - (NSEvent *)tkProcessEvent:(NSEvent *)theEvent;
diff --git a/macosx/tkMacOSXSubwindows.c b/macosx/tkMacOSXSubwindows.c
index d23ba85..f026318 100644
--- a/macosx/tkMacOSXSubwindows.c
+++ b/macosx/tkMacOSXSubwindows.c
@@ -131,11 +131,6 @@ XMapWindow(
 {
     MacDrawable *macWin = (MacDrawable *) window;
     XEvent event;
-    /*
-     * This function can be called from outside the AppKit event
-     * loop, so it needs its own AutoreleasePool.
-     */
-    NSAutoreleasePool* pool = [NSAutoreleasePool new];
 
     /*
      * Under certain situations it's possible for this function to be called
@@ -158,6 +153,7 @@ XMapWindow(
 	    if ( [win canBecomeKeyWindow] ) {
 		[win makeKeyAndOrderFront:NSApp];
 	    }
+	    /* Why do we need this? (It is used by Carbon)*/
 	    [win windowRef];
 	    TkMacOSXApplyWindowAttributes(macWin->winPtr, win);
 	}
@@ -194,7 +190,6 @@ XMapWindow(
     event.xvisibility.type = VisibilityNotify;
     event.xvisibility.state = VisibilityUnobscured;
     NotifyVisibility(macWin->winPtr, &event);
-    [pool drain];
 }
 
 /*
@@ -318,7 +313,6 @@ XResizeWindow(
     unsigned int height)
 {
     MacDrawable *macWin = (MacDrawable *) window;
-    NSAutoreleasePool *pool= [NSAutoreleasePool new];
     display->request++;
     if (Tk_IsTopLevel(macWin->winPtr) && !Tk_IsEmbedded(macWin->winPtr)) {
 	NSWindow *w = macWin->winPtr->wmInfoPtr->window;
@@ -333,7 +327,6 @@ XResizeWindow(
     } else {
 	MoveResizeWindow(macWin);
     }
-    [pool drain];
 }
 
 /*
@@ -366,7 +359,6 @@ XMoveResizeWindow(
     display->request++;
     if (Tk_IsTopLevel(macWin->winPtr) && !Tk_IsEmbedded(macWin->winPtr)) {
 	NSWindow *w = macWin->winPtr->wmInfoPtr->window;
-
 	if (w) {
 	    NSRect r = NSMakeRect(x + macWin->winPtr->wmInfoPtr->xInParent,
 		    tkMacOSXZeroScreenHeight - (y +
@@ -407,7 +399,6 @@ XMoveWindow(
     display->request++;
     if (Tk_IsTopLevel(macWin->winPtr) && !Tk_IsEmbedded(macWin->winPtr)) {
 	NSWindow *w = macWin->winPtr->wmInfoPtr->window;
-
 	if (w) {
 	    [w setFrameTopLeftPoint:NSMakePoint(x, tkMacOSXZeroScreenHeight - y)];
 	}
diff --git a/macosx/tkMacOSXWindowEvent.c b/macosx/tkMacOSXWindowEvent.c
index 851358d..1150f2e 100644
--- a/macosx/tkMacOSXWindowEvent.c
+++ b/macosx/tkMacOSXWindowEvent.c
@@ -806,7 +806,7 @@ ConfigureRestrictProc(
 {
     const NSRect *rectsBeingDrawn;
     NSInteger rectsBeingDrawnCount;
-
+    
     [self getRectsBeingDrawn:&rectsBeingDrawn count:&rectsBeingDrawnCount];
 
 #ifdef TK_MAC_DEBUG_DRAWING
@@ -840,7 +840,8 @@ ConfigureRestrictProc(
 
 -(void) setFrameSize: (NSSize)newsize
 {
-    if ( [self inLiveResize] ) {
+    [super setFrameSize: newsize];
+    if ([self inLiveResize]) {
 	NSWindow *w = [self window];
 	TkWindow *winPtr = TkMacOSXGetTkWindow(w);
 	Tk_Window tkwin = (Tk_Window) winPtr;
@@ -849,17 +850,29 @@ ConfigureRestrictProc(
 	ClientData oldArg;
     	Tk_RestrictProc *oldProc;
 
-	/* Resize the NSView */
-	[super setFrameSize: newsize];
-
-	/* Disable drawing until the window has been completely configured.*/
+	/* This can be called from outside the Tk event loop.
+	 * Since it calls Tcl_DoOneEvent, we need to make sure we
+	 * don't clobber the AutoreleasePool set up by the caller.
+	 */
+	[NSApp setPoolProtected:YES];
+	
+	/*
+	 * Try to prevent flickers and flashes.
+	 *
+	 * This stops the flickers on OSX 10.11. But flashes still occur when
+	 * the width of the window is 16, 32, 48, 64, 80, 96, 112, 256, 512,
+	 * 768, ... :^(
+	 */
+	[w disableFlushWindow];
+	
+	/* Disable Tk drawing until the window has been completely configured.*/
 	TkMacOSXSetDrawingEnabled(winPtr, 0);
 
 	 /* Generate and handle a ConfigureNotify event for the new size.*/
 	TkGenWMConfigureEvent(tkwin, Tk_X(tkwin), Tk_Y(tkwin), width, height,
 			      TK_SIZE_CHANGED | TK_MACOSX_HANDLE_EVENT_IMMEDIATELY);
     	oldProc = Tk_RestrictEvents(ConfigureRestrictProc, NULL, &oldArg);
-	while ( Tk_DoOneEvent(TK_X_EVENTS|TK_DONT_WAIT) ) {}
+	while (Tk_DoOneEvent(TK_X_EVENTS|TK_DONT_WAIT)) {}
     	Tk_RestrictEvents(oldProc, oldArg, &oldArg);
 
 	/* Now that Tk has configured all subwindows we can create the clip regions. */
@@ -871,9 +884,10 @@ ConfigureRestrictProc(
 	HIRect bounds = NSRectToCGRect([self bounds]);
 	HIShapeRef shape = HIShapeCreateWithRect(&bounds);
 	[self generateExposeEvents: shape];
-	while ( Tk_DoOneEvent(TK_ALL_EVENTS|TK_DONT_WAIT) ) {}
-    } else {
-        [super setFrameSize: newsize];
+	while (Tk_DoOneEvent(TK_ALL_EVENTS|TK_DONT_WAIT)) {}
+	[w enableFlushWindow];
+	[w flushWindowIfNeeded];
+	[NSApp setPoolProtected:NO];
     }
 }
 
@@ -891,12 +905,10 @@ ConfigureRestrictProc(
     [self generateExposeEvents: shape];
 }
 
-/* Core method of this class: generates expose events for redrawing.
- * Whereas drawRect is intended to be called only from the Appkit event
- * loop, this can be called from Tk.  If the Tcl_ServiceMode is set to
- * TCL_SERVICE_ALL then the expose events will be immediately removed
- * from the Tcl event loop and processed.  Typically, they should be queued,
- * however.
+/* Core method of this class: generates expose events for redrawing.  If the
+ * Tcl_ServiceMode is set to TCL_SERVICE_ALL then the expose events will be
+ * immediately removed from the Tcl event loop and processed.  Typically, they
+ * should be queued, however.
  */
 - (void) generateExposeEvents: (HIShapeRef) shape
 {
diff --git a/macosx/tkMacOSXWm.c b/macosx/tkMacOSXWm.c
index 5ec38ca..308ee11 100644
--- a/macosx/tkMacOSXWm.c
+++ b/macosx/tkMacOSXWm.c
@@ -404,18 +404,23 @@ static void		RemapWindows(TkWindow *winPtr,
     if (title == nil) {
 	title = "unnamed window";
     }
-    printf("Retained <%s>. Count is: %lu\n", title, [self retainCount]);
+    if (DEBUG_ZOMBIES > 1){
+	printf("Retained <%s>. Count is: %lu\n", title, [self retainCount]);
+    }
     return result;
 }
 
 - (id) autorelease
 {
+    static int xcount = 0;
     id result = [super autorelease];
     const char *title = [[self title] UTF8String];
     if (title == nil) {
 	title = "unnamed window";
     }
-    printf("Autoreleased <%s>. Count is %lu\n", title, [self retainCount]);
+    if (DEBUG_ZOMBIES > 1){
+	printf("Autoreleased <%s>. Count is %lu\n", title, [self retainCount]);
+    }
     return result;
 }
 
@@ -424,9 +429,24 @@ static void		RemapWindows(TkWindow *winPtr,
     if (title == nil) {
 	title = "unnamed window";
     }
-    printf("Releasing <%s>. Count is %lu\n", title, [self retainCount]);
+    if (DEBUG_ZOMBIES > 1){
+	printf("Releasing <%s>. Count is %lu\n", title, [self retainCount]);
+    }
     [super release];
 }
+
+- (void) dealloc {
+    const char *title = [[self title] UTF8String];
+    if (title == nil) {
+	title = "unnamed window";
+    }
+    if (DEBUG_ZOMBIES > 0){
+	printf(">>>> Freeing <%s>. Count is %lu\n", title, [self retainCount]);
+    }
+    [super dealloc];
+}
+
+
 #endif
 @end
 
@@ -541,7 +561,6 @@ FrontWindowAtPoint(
     int x, int y)
 {
     NSPoint p = NSMakePoint(x, tkMacOSXZeroScreenHeight - y);
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
     NSArray *windows = [NSApp orderedWindows];
     TkWindow *front = NULL;
 
@@ -551,7 +570,6 @@ FrontWindowAtPoint(
 		break;
 	    }
 	}
-    [pool drain];
     return front;
 }
 
@@ -855,7 +873,6 @@ TkWmDeadWindow(
     NSWindow *window = wmPtr->window;
 
     if (window && !Tk_IsEmbedded(winPtr) ) {
-	NSAutoreleasePool *pool = [NSAutoreleasePool new];
 	NSWindow *parent = [window parentWindow];
 	if (parent) {
 	    [parent removeChildWindow:window];
@@ -865,26 +882,30 @@ TkWmDeadWindow(
         if (winPtr->window) {
             ((MacDrawable *) winPtr->window)->view = nil;
         }
-#if DEBUG_ZOMBIES
+#if DEBUG_ZOMBIES > 0
 	{
 	    const char *title = [[window title] UTF8String];
 	    if (title == nil) {
 		title = "unnamed window";
 	    }
-	    printf("Closing <%s>. Count is: %lu\n", title, [window retainCount]);
+	    printf(">>>> Closing <%s>. Count is: %lu\n", title, [window retainCount]);
 	}
 #endif
         [window release];
 	wmPtr->window = NULL;
-       /* Activate the highest window left on the screen. */
-       NSArray *windows = [NSApp orderedWindows];
-       if ( [windows count] > 0 ) {
-	   NSWindow *front = [windows objectAtIndex:0];
-	   if ( front && [front canBecomeKeyWindow] ) {
-               [front makeKeyAndOrderFront:NSApp];
-           }
-       }
-       [pool drain];
+
+	/* Activate the highest window left on the screen. */
+	NSArray *windows = [NSApp orderedWindows];
+	if ( [windows count] > 0 ) {
+	    NSWindow *front = [windows objectAtIndex:0];
+	    if ( front && [front canBecomeKeyWindow] ) {
+		[front makeKeyAndOrderFront:NSApp];
+	    }
+	}
+#if DEBUG_ZOMBIES > 0
+	fprintf(stderr, "================= Pool dump ===================\n");
+	[NSAutoreleasePool showPools];
+#endif
     }
     ckfree(wmPtr);
     winPtr->wmInfoPtr = NULL;
@@ -5538,9 +5559,6 @@ TkMacOSXMakeRealWindowExist(
 	 * TODO: Here we should handle out of process embedding.
 	 */
     }
-
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
-
     WindowClass macClass = wmPtr->macClass;
     wmPtr->attributes &= (tkAlwaysValidAttributes |
 	    macClassAttrs[macClass].validAttrs);
@@ -5574,10 +5592,10 @@ TkMacOSXMakeRealWindowExist(
     NSWindow *window = [[winClass alloc] initWithContentRect:contentRect
 	    styleMask:styleMask backing:NSBackingStoreBuffered defer:YES];
     if (!window) {
-	Tcl_Panic("couldn't allocate new Mac window");
+    	Tcl_Panic("couldn't allocate new Mac window");
     }
     TKContentView *contentView = [[TKContentView alloc]
-	    initWithFrame:NSZeroRect];
+				     initWithFrame:NSZeroRect];
     [window setContentView:contentView];
     [contentView release];
     [window setDelegate:NSApp];
@@ -5612,7 +5630,7 @@ TkMacOSXMakeRealWindowExist(
 
     [window setDocumentEdited:NO];
     wmPtr->window = window;
-    macWin->view = contentView;
+    macWin->view = window.contentView;
     TkMacOSXApplyWindowAttributes(winPtr, window);
 
     NSRect geometry = InitialWindowBounds(winPtr, window);
@@ -5621,11 +5639,8 @@ TkMacOSXMakeRealWindowExist(
     geometry.origin.y = tkMacOSXZeroScreenHeight - (geometry.origin.y +
 	    geometry.size.height);
     [window setFrame:geometry display:NO];
-
     TkMacOSXRegisterOffScreenWindow((Window) macWin, window);
     macWin->flags |= TK_HOST_EXISTS;
-
-    [pool drain];
 }
 
 /*
@@ -6018,7 +6033,6 @@ TkpChangeFocus(
 
     if (Tk_IsTopLevel(winPtr) && !Tk_IsEmbedded(winPtr) ){
     	NSWindow *win = TkMacOSXDrawableWindow(winPtr->window);
-	NSAutoreleasePool *pool = [NSAutoreleasePool new];
     	TkWmRestackToplevel(winPtr, Above, NULL);
     	if (force ) {
     	    [NSApp activateIgnoringOtherApps:YES];
@@ -6026,7 +6040,6 @@ TkpChangeFocus(
 	if ( win && [win canBecomeKeyWindow] ) {
 	    [win makeKeyAndOrderFront:NSApp];
 	}
-	[pool drain];
     }
 
     /*
diff --git a/macosx/tkMacOSXXStubs.c b/macosx/tkMacOSXXStubs.c
index c39d42d..53d1eb8 100644
--- a/macosx/tkMacOSXXStubs.c
+++ b/macosx/tkMacOSXXStubs.c
@@ -142,8 +142,8 @@ TkpOpenDisplay(
     static NSRect maxBounds = {{0, 0}, {0, 0}};
     static char vendor[25] = "";
     NSArray *cgVers;
-
-
+    NSAutoreleasePool *pool = [NSAutoreleasePool new];
+    
     if (gMacDisplay != NULL) {
 	if (strcmp(gMacDisplay->display->display_name, display_name) == 0) {
 	    return gMacDisplay;
@@ -152,8 +152,6 @@ TkpOpenDisplay(
 	}
     }
 
-    NSAutoreleasePool *pool = [NSAutoreleasePool new];
-
     display = ckalloc(sizeof(Display));
     screen  = ckalloc(sizeof(Screen));
     bzero(display, sizeof(Display));