Bug 1398: Crash only occurs @ -[NSOpenGLContext setView:] when using XCode 11 _and_ its default SDK 'macosx10.15'
This patch demonstrates that using the SDK 'macosx10.11' does not cause the crash @ -[NSOpenGLContext setView:].
SDK 'macosx10.15' enforces Apple's own Cargo Cult of 'main-thread' by throwing a SIGILL signal (or SIGABRT) - essentially an exception.
This surely renders our code officially invalid due to this policy, i.e. we are not allowed to issue [* setView] on any non main-thread.
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The crash occurs independently of used Java version on Java 8 - 11, as well as on JogAmp 2.3.2 - current master tip.
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The initial remedy to issue said action on the main-thread in a blocking/wait manner has the risk to deadlock, due to
1) [NSOpenGLContext setView:] itself using a mutex (Thanks to Ken Harris's analysis)
and
(2) in case where we are 'thread hopping': - [main-thread] Event like 'window ready' -> kick off action on EDT-thread *blocking* - [EDT-thread] Create stuff incl OpenGLContext -> kick off setView on main-thread *blocking*
This has to be further investigated.
This crash finally has been reliably reproduced now.
Set NSOpenGLContext's NSView via [NSOpenGLContext setView:] on the main-thread as enforced since XCode 11 using SDL macosx10.15, using Runnable SetNSViewCmd.
This operation must be performed async w/o blocking to allow other tasks locking the NativeSurface on main-thread to complete.
Further, since [NSOpenGLContext setView:] acquired the CGLContext lock, it can't be locked until this task has been completed.
Worst case scenario for a late [NSOpenGLContext setView:] issuance might be corrupt initial frame(s) displayed.
Since all concurrent locking is performed within JOGL, the unlocked CGLContext window risk is only academic. However, if native 3rd party toolkits take share control, we might have a situation.
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SetNSViewCmd is issued @ makeCurrent() now as opposed to createContext(..) and associateDrawable(true). The latter was actually late as well, as it also happened after makeCurrent when updating the drawable association. It also missed setting a null NSView when detached!
release() will also set a null NSView if called after associateDrawable(false).
SetNSViewCmd will only be issued if the NSView has been changed, i.e. first makeCurrent() or changing the drawable. If issued, makeCurrent() will not lock the underlying CGLContext and hence allow SetNSViewCmd to perform - see above.
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NSViewDescriptor class structure replaces the less convenient method 'getNSViewHandle(..)', exposing all collected drawable characteristics as fields. NSViewDescriptor also respects a ProxySurface's OPT_UPSTREAM_SURFACELESS mode, which results in not using any underlying NSView - similar to OPT_UPSTREAM_WINDOW_INVISIBLE.
This change ensures that all surfaceless GL operations will not use any NSView.
OSX/SWT Testing: Drop using 'com.jogamp.newt.util.MainThread' enforcing default test behavior
SWT and OSX's UI TK have their strict threading policy we require to comply with, e.g. see Bug 1398 lately.
It doesn't help using our own MainThread vehicle to move the unit test on the OS main thread, as this removes potential causes of deadlocks - which we intend to find and resolve.
This patch removed using MainThread altogether from our ant unit testing recipe as well from our manual test scripts.
Unit tests are no more executed on the 'main thread'.
SWT tests are patched to comply with SWT's UI threading policy.
We also catch violations within NewtCanvasSWT and our SWT GLCanvas to provide same behavior on all platforms.
Bug 1398: Ensure CGLContext lock will be acquired before leaving user makeCurrent() call
Command SetNSViewCmd sets NSOpenGLContext's NSView via [NSOpenGLContext setView:] on the main-thread as enforced since XCode 11 using SDK macosx10.15, see Bug 1398.
This command is injected into OSX's main-thread @ NSOpenGLImpl.makeCurrent(long) only if required, i.e. issued only for a newly bound NSView and skipped for surface-less or offscreen 'surfaces'.
This operation must be performed w/o blocking other tasks locking the NativeSurface on main-thread to complete.
Since [NSOpenGLContext setView:] acquires the CGLContext lock on the main-thread, it can't be locked by the calling thread until this task has been completed. Command issuer NSOpenGLImpl.makeCurrent(long) will not acquire the CGLContext lock if this command is pending.
contextMadeCurrent(true) cures the potential unlocked CGLContext by issuing a whole GLContext.release() and GLContext.makeCurrent() cycle while waiting for this command to be completed in-between. This GLContext cycle also ensures an unlocked NativeSurface.getLock() in-between, allowing potentially blocked other tasks on the main-thread to complete and hence this queued command to execute.
Notable test provoking critical multithreading issues is com.jogamp.opengl.test.junit.jogl.demos.es2.newt.TestGearsES2NewtCanvasSWT. Notable test exposing issues with an unlocked CGLContext is com.jogamp.opengl.test.junit.jogl.glsl.TestGLSLShaderState02NEWT.
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