kc3-lang/SDL

2020-03-01T12:58:50

Fixed bug 4369 - Going fullscreen with green knob in MacOS freezes app for 15 seconds. Elmar creating a fullscreen window with SDL_CreateWindow(..SDL_WINDOW_FULLSCREEN_DESKTOP..) in MacOS works fine, except if it was triggered by the user with the green knob in the top left window title bar. Then "something" is different, and SDL_CreateWindow hangs for 15-20 seconds (tested in MacOS 10.13 and 10.14). Responsible for the hang is this code in SDL_cocoawindow.m - Cocoa_SetWindowFullscreenSpace: const int maxattempts = 3; int attempt = 0; while (++attempt <= maxattempts) { /* Wait for the transition to complete, so application changes take effect properly (e.g. setting the window size, etc.) */ const int limit = 10000; int count = 0; while ([data->listener isInFullscreenSpaceTransition]) { if ( ++count == limit ) { /* Uh oh, transition isn't completing. Should we assert? */ break; } SDL_Delay(1); SDL_PumpEvents(); } if ([data->listener isInFullscreenSpace] == (state ? YES : NO)) break; /* Try again, the last attempt was interrupted by user gestures */ if (![data->listener setFullscreenSpace:(state ? YES : NO)]) break; /* ??? */ } One trivial workaround is to change 'const int limit = 10000' to 500. Then the freeze is so short that it doesn't look like a freeze to the user. Looking further into the problem, I observed that the function Cocoa_SetWindowFullscreenSpace recursively calls itself via some ObjectiveC messages. I managed to extract a callstack for this (copied below): Note how Cocoa_SetWindowFullscreenSpace in stack line 22 calls SDL_PumpEvents, which eventually arrives at SDL_SendWindowEvent, which calls SDL_UpdateFullscreenMode (stack line 0), which then calls Cocoa_SetWindowFullscreenSpace again (not shown). This recursive second call is the one that hangs. Another "solution" that worked for me was to add a flag to SDL_Window that is set in Cocoa_SetWindowFullscreenSpace and causes this function to return immediately if called from itself. Obviously, this is also an ugly hack, but I don't have enough time to dive into this crazy Cocoa/ObjectiveC business deep enough to find a proper solution. But hopefully it's easy for one of the experts around. Note that there is a "failure to go fullscreen"-message involved, maybe using the green knob causes this failure at first. I can unfortunately not provide a minimum example. Best regards, Elmar 0 com.yasara.View 0x00000001007495af SDL_UpdateFullscreenMode + 207 1 com.yasara.View 0x00000001006e2591 SDL_SendWindowEvent + 401 2 com.yasara.View 0x0000000100775a72 -[Cocoa_WindowListener windowDidResize:] + 370 3 com.yasara.View 0x0000000100776550 -[Cocoa_WindowListener windowDidExitFullScreen:] + 512 4 com.apple.AppKit 0x00007fff3180a2a4 -[_NSWindowEnterFullScreenTransitionController failedToEnterFullScreen] + 692 5 com.apple.AppKit 0x00007fff31c59737 -[_NSEnterFullScreenTransitionController _doFailedToEnterFullScreen] + 349 6 com.apple.AppKit 0x00007fff3172aa53 __NSFullScreenDockConnectionSendEnterForSpace_block_invoke + 135 7 libxpc.dylib 0x00007fff6114b9b1 _xpc_connection_reply_callout + 36 8 libxpc.dylib 0x00007fff6114b938 _xpc_connection_call_reply_async + 82 9 libdispatch.dylib 0x00007fff60ec7e39 _dispatch_client_callout3 + 8 10 libdispatch.dylib 0x00007fff60ede3b0 _dispatch_mach_msg_async_reply_invoke + 322 11 libdispatch.dylib 0x00007fff60ed2e25 _dispatch_main_queue_callback_4CF + 807 12 com.apple.CoreFoundation 0x00007fff33d39e8b __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9 13 com.apple.CoreFoundation 0x00007fff33d3959a __CFRunLoopRun + 2335 14 com.apple.CoreFoundation 0x00007fff33d38a28 CFRunLoopRunSpecific + 463 15 com.apple.HIToolbox 0x00007fff32fd1b35 RunCurrentEventLoopInMode + 293 16 com.apple.HIToolbox 0x00007fff32fd1774 ReceiveNextEventCommon + 371 17 com.apple.HIToolbox 0x00007fff32fd15e8 _BlockUntilNextEventMatchingListInModeWithFilter + 64 18 com.apple.AppKit 0x00007fff3128deb7 _DPSNextEvent + 997 19 com.apple.AppKit 0x00007fff3128cc56 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1362 20 com.yasara.View 0x000000010076fab2 Cocoa_PumpEvents + 290 21 com.yasara.View 0x00000001006dd1c7 SDL_PumpEvents_REAL + 23 22 com.yasara.View 0x00000001007795cf Cocoa_SetWindowFullscreenSpace + 223 23 com.yasara.View 0x000000010074970b SDL_UpdateFullscreenMode + 555 24 com.yasara.View 0x00000001006e2476 SDL_SendWindowEvent + 118 25 com.yasara.View 0x0000000100774ff7 -[Cocoa_WindowListener resumeVisibleObservation] + 135 26 com.yasara.View 0x000000010077664c Cocoa_ShowWindow + 188 27 com.yasara.View 0x0000000100749492 SDL_FinishWindowCreation + 546 28 com.yasara.View 0x0000000100748da5 SDL_CreateWindow_REAL + 1573 29 com.yasara.View 0x000000010010d9b1 vga_setvideomode + 1347 30 com.yasara.View 0x00000001003f0d46 mod_initscreen + 2614 31 com.yasara.View 0x00000001003f344b mod_reinitscreen + 460 32 com.yasara.View 0x00000001003f370d mod_resizescreen + 383 33 com.yasara.View 0x0000000100418e39 mod_main + 815 34 com.yasara.View 0x000000010029ca5d main2 + 5766 35 com.yasara.View 0x000000010011d1b7 main.main_cpuok + 19

diff --git a/src/video/cocoa/SDL_cocoawindow.h b/src/video/cocoa/SDL_cocoawindow.h
index c558d75..049d00f 100644
--- a/src/video/cocoa/SDL_cocoawindow.h
+++ b/src/video/cocoa/SDL_cocoawindow.h
@@ -116,7 +116,7 @@ struct SDL_WindowData
     NSView *sdlContentView; /* nil if window is created via CreateWindowFrom */
     NSMutableArray *nscontexts;
     SDL_bool created;
-    SDL_bool inWindowMove;
+    SDL_bool inWindowFullscreenTransition;
     Cocoa_WindowListener *listener;
     struct SDL_VideoData *videodata;
 #if SDL_VIDEO_OPENGL_EGL
diff --git a/src/video/cocoa/SDL_cocoawindow.m b/src/video/cocoa/SDL_cocoawindow.m
index 79e1b9d..3526e10 100644
--- a/src/video/cocoa/SDL_cocoawindow.m
+++ b/src/video/cocoa/SDL_cocoawindow.m
@@ -2030,6 +2030,11 @@ Cocoa_SetWindowFullscreenSpace(SDL_Window * window, SDL_bool state)
     SDL_bool succeeded = SDL_FALSE;
     SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
 
+	if (data->inWindowFullscreenTransition) {
+		return SDL_FALSE;
+	}
+
+	data->inWindowFullscreenTransition = SDL_TRUE;
     if ([data->listener setFullscreenSpace:(state ? YES : NO)]) {
         const int maxattempts = 3;
         int attempt = 0;
@@ -2056,6 +2061,7 @@ Cocoa_SetWindowFullscreenSpace(SDL_Window * window, SDL_bool state)
         /* Return TRUE to prevent non-space fullscreen logic from running */
         succeeded = SDL_TRUE;
     }
+	data->inWindowFullscreenTransition = SDL_FALSE;
 
     return succeeded;
 }}