RunOnMainThread(waitUntilDone:=true,..) can deadlock the main-thread if called from AWT-EDT, since the main-thread may call back to AWT-EDT while injecting a new main-thread task.
This patch revises all RunOnMainThread CALayer usage, resulting in only one required left: - OSXUtil.AddCASublayer() w/ waitUntilDone:=false
Hence the CALayer code has no more potential to deadlock main-thread/AWT-EDT.
OSXUtil.AddCASublayer() must be performed on main-thread, otherwise the CALayer attachment will fail - no visible rendering result.
+++
Note: A good trigger to test this deadlock is to magnify/zoom the OSX desktop (click background + ctrl-mouse_wheel) before running some unit tests.
TestGLCanvasAWTActionDeadlock01AWT and TestAddRemove02GLWindowNewtCanvasAWT also have the potential to trigger the mentioned deadlock.
In case a reparent action takes place w/ recreate, only preserve the GLEventListenerState if the window is valid and will become visible again (wasVisible).
Also add proper DEBUG log prefix to GLEventListenerState.
Remodel OSX/CALayer Threading (commit 896e8b021b39e9415040a57a1d540d7d24b02db1): Run on main-thread w/o blocking ; Misc Changes
Commit 896e8b021b39e9415040a57a1d540d7d24b02db1 moved all native CALayer calls to the current thread to avoid deadlocks.
Even though this seemed to be fine at least resource GC (release/dealloc calls) were issued very late in time, probably due to multithreading synchronization of JAWT and/or OSX API.
Example: Our 'TestAddRemove01GLCanvasSwingAWT' test didn't freed CALayer resources incl. GL ctx when destroying the objects (AWT Frame, GLCanvas, ..), leading to resource starvation .. eventually.
Remedy is a compromise of behavior before commit 896e8b021b39e9415040a57a1d540d7d24b02db1 and that commit, i.e. to run CALayer lifecycle methods on main-thread, but do not block!
The careful part within MacOSXCGLContext.associateDrawable(..) performs the following block on main-thread: - lock the context - create NSOpenGLLayer (incl. it's own shared GL context and the DisplayLink) - attach NSOpenGLLayer to root CALayer - unlock the context
Due to the GL ctx locking, this async offthread operation is safe within our course of operations.
Details: - NSOpenGLContext - Context and CVDisplayLink creation at init - Call [ctx update] if texture/frame size changed - 'waitUntilRenderSignal' uses default TO value if given TO is 0 to avoid deadlocks
- MacOSXCGLDrawable/MacOSXPbufferCGLDrawable: remove getNSViewHandle() method. MacOSXCGLContext uses common code to detect nature of the drawable handle.
- MacOSXCGLContext/CALayer: Use safe screenVSyncTimeout values, never 0 to avoid deadlock!
- JAWTWindow.invalidate: Call detachSurfaceLayer() if not done yet
Part2 misses essential locking of the OpenGL context (and it's surface upfront) while creating the NSOpenGLLayer instance. The latter instantiates a OpenGL context shared w/ JOGL's, hence it cannot be locked.
Encapsulating NSOpenGLLayer creation/attachment and it's detachment/release in sub-classes AttachNSOpenGLLayer and DetachNSOpenGLLayer, where instances will be streamed on main-thread.
Both tasks are triggered at associateDrawable(boolean bound).
The mentioned GL context locking requires disturbs the 'streaming' design considerably in AttachNSOpenGLLayer. It is solved by attempt to acquire the recursive lock of the surface and the context via 'tryLock(maxwait)' w/ screen-vSync-period/2. If the locks could not be acquired completly, the AttachNSOpenGLLayer instance will be re-queued to the main-thread for later execution.
Before DetachNSOpenGLLayer is being streamed, it is validated whether AttachNSOpenGLLayer did run. A recursive situation does happen w/ resizing an offscreen pbuffer drawable! Hence extra care is being taken.
OSX/NEWT: Following CALayer streaming design, i.e. issue NSWindow/NSView Ops on main-thread w/o blocking; NEWT/WindowImpl: Volatile multithreaded mutable values
Similar to commits: 28c6472335b924080d638b33a28f8f4eedb459b1 f354fb204d8973453c538dda78a2c82c87be61dc
main-thread operations cannot block main-thread.
Luckily we are able to create the NSWindow and NSView instance uninitialized (deferred) on the current thread, while issuing their initialization on the main-thread w/o blocking.
Further more a size glitch is fixed, which didn't take the title bar into account.