GC deadlock: process hang in ToggleRefRetainDeadlockTest

The ToggleRefRetainDeadlockTest test deadlocked in https://github.com/xamarin/xamarin-macios/pull/14499#issuecomment-1079565664.

Thread stack traces
ldb) thread backtrace all
thread #1, name = 'tid_103', queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
* frame #0: 0x00007ff80c2fe506 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007ff80c338a69 libsystem_pthread.dylib`_pthread_cond_wait + 1224
frame #2: 0x0000000105996447 xammac_tests`mono_os_event_wait_multiple [inlined] mono_os_cond_wait(cond=, mutex=) at mono-os-mutex.h:219:8 [opt]
frame #3: 0x0000000105996437 xammac_tests`mono_os_event_wait_multiple(events=0x00007ff7ba8a9aa8, nevents=1, waitall=1, timeout=4294967295, alertable=1) at os-event-unix.c:190:4 [opt]
frame #4: 0x0000000105996284 xammac_tests`mono_os_event_wait_one(event=0x000060001198d310, timeout=, alertable=) at os-event-unix.c:94:9 [opt]
frame #5: 0x000000010599331d xammac_tests`mono_thread_info_wait_one_handle(thread_handle=, timeout=, alertable=) at mono-threads.c:2042:8 [opt]
frame #6: 0x000000010590dd07 xammac_tests`ves_icall_System_Threading_Thread_Join_internal at threads.c:2185:9 [opt]
frame #7: 0x000000010590dcdc xammac_tests`ves_icall_System_Threading_Thread_Join_internal(thread_handle=, ms=, error=0x00007ff7ba8a9b48) at threads.c:2241:8 [opt]
frame #8: 0x0000000105865711 xammac_tests`ves_icall_System_Threading_Thread_Join_internal_raw(a0=0x00007ff7ba8a9c10, a1=-1) at icall-def.h:1033:1 [opt]
frame #9: 0x000000011035c2c3
frame #10: 0x0000000105787a13 xammac_tests`mono_jit_runtime_invoke(method=, obj=, params=0x00007ff7ba8a9f50, exc=, error=) at mini-runtime.c:3217:12 [opt]
frame #11: 0x00000001058bc0b8 xammac_tests`mono_runtime_invoke_checked [inlined] do_runtime_invoke(method=0x00007fe8722f4720, obj=0x0000000108006150, params=0x00007ff7ba8a9f50, exc=0x0000000000000000, error=0x00007ff7ba8aa078) at object.c:3052:11 [opt]
frame #12: 0x00000001058bc082 xammac_tests`mono_runtime_invoke_checked(method=0x00007fe8722f4720, obj=0x0000000108006150, params=0x00007ff7ba8a9f50, error=0x00007ff7ba8aa078) at object.c:3220:9 [opt]
frame #13: 0x00000001058c4d8f xammac_tests`mono_runtime_try_invoke_array(method=, obj=, params=, exc=0x0000000000000000, error=) at object.c:5630:10 [opt]
frame #14: 0x000000010584ade7 xammac_tests`ves_icall_InternalInvoke(method_handle=, this_arg_handle=, params_handle=, exception_out=, error=0x00007ff7ba8aa078) at icall.c:3935:11 [opt]
frame #15: 0x000000010585d817 xammac_tests`ves_icall_InternalInvoke_raw(a0=0x00007ff7ba8aa158, a1=0x00007ff7ba8aa160, a2=0x00007ff7ba8aa168, a3=0x00007ff7ba8aa150) at icall-def.h:667:1 [opt]
frame #16: 0x000000010c038849
frame #17: 0x000000010c0381d9
frame #18: 0x000000010c037f2b
frame #19: 0x000000010c01f1ec
frame #20: 0x000000010c01e853
frame #21: 0x000000010c025f8b
frame #22: 0x000000010c01e853
frame #23: 0x000000010c025f8b
frame #24: 0x000000010c01e853
frame #25: 0x000000010c025f8b
frame #26: 0x000000010c01e853
frame #27: 0x000000010c025f8b
frame #28: 0x000000010c01e853
frame #29: 0x000000010c01bab3
frame #30: 0x000000010bf694cb
frame #31: 0x000000010bf693f3
frame #32: 0x0000000109b8cf13
frame #33: 0x0000000109b8cc93
frame #34: 0x0000000109b8a90b
frame #35: 0x0000000109b8a49b
frame #36: 0x0000000105787a13 xammac_tests`mono_jit_runtime_invoke(method=, obj=, params=0x00007ff7ba8ab558, exc=, error=) at mini-runtime.c:3217:12 [opt]
frame #37: 0x00000001058bc0b8 xammac_tests`mono_runtime_invoke_checked [inlined] do_runtime_invoke(method=0x00007fe8712a9648, obj=0x00000001080600c8, params=0x00007ff7ba8ab558, exc=0x0000000000000000, error=0x00007ff7ba8ab4a8) at object.c:3052:11 [opt]
frame #38: 0x00000001058bc082 xammac_tests`mono_runtime_invoke_checked(method=0x00007fe8712a9648, obj=0x00000001080600c8, params=0x00007ff7ba8ab558, error=0x00007ff7ba8ab4a8) at object.c:3220:9 [opt]
frame #39: 0x00000001058c099e xammac_tests`mono_runtime_invoke(method=0x00007fe8712a9648, obj=0x00000001080600c8, params=0x00007ff7ba8ab558, exc=) at object.c:3107:9 [opt]
frame #40: 0x00000001059a82e2 xammac_tests`native_to_managed_trampoline_5(objc_object*, objc_selector*, _MonoMethod**, unsigned int) + 258
frame #41: 0x00000001059ae319 xammac_tests`-[__MonoMac_NSActionDispatcher xamarinApplySelector] + 41
frame #42: 0x00007ff80d252fc7 Foundation`-[NSObject(NSThreadPerformAdditions) performSelector:onThread:withObject:waitUntilDone:modes:] + 400
frame #43: 0x00007ff80d252cd7 Foundation`-[NSObject(NSThreadPerformAdditions) performSelectorOnMainThread:withObject:waitUntilDone:] + 124
frame #44: 0x0000000109b898bb
frame #45: 0x000000010920e600 dyld`_pthread_list_lock + 60
thread #4, name = 'EventPumpThread'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe872419600) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cbc0 xammac_tests`mono_threads_state_poll_with_info(info=0x00007fe872419600) at mono-threads-coop.c:149:3 [opt]
frame #4: 0x000000010598d26b xammac_tests`mono_threads_enter_gc_unsafe_region_unbalanced_with_info(info=, stackdata=) at mono-threads-coop.c:485:3 [opt]
frame #5: 0x000000010578a097 xammac_tests`mono_magic_trampoline(regs=0x0000700005e20718, code="H\x8b\xfdH\x83Lj\xbe(", arg=0x00007fe871047780, tramp=) at mini-trampolines.c:769:2 [opt]
frame #6: 0x0000000107d60393
frame #7: 0x000000010c020893
frame #8: 0x000000010c02040b
frame #9: 0x000000010c01efe8
frame #10: 0x000000010c01e60b
frame #11: 0x0000000105787a13 xammac_tests`mono_jit_runtime_invoke(method=, obj=, params=0x0000700005e20f58, exc=, error=) at mini-runtime.c:3217:12 [opt]
frame #12: 0x00000001058bc0b8 xammac_tests`mono_runtime_invoke_checked [inlined] do_runtime_invoke(method=0x00007fe873039588, obj=0x0000000108093098, params=0x0000700005e20f58, exc=0x0000000000000000, error=0x0000700005e20ef0) at object.c:3052:11 [opt]
frame #13: 0x00000001058bc082 xammac_tests`mono_runtime_invoke_checked(method=0x00007fe873039588, obj=0x0000000108093098, params=0x0000700005e20f58, error=0x0000700005e20ef0) at object.c:3220:9 [opt]
frame #14: 0x00000001058c2afd xammac_tests`mono_runtime_delegate_try_invoke(delegate=0x0000000108093098, params=0x0000700005e20f58, exc=0x0000000000000000, error=0x0000700005e20ef0) at object.c:4438:7 [opt]
frame #15: 0x0000000105914db7 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1255:3 [opt]
frame #16: 0x0000000105914b0e xammac_tests`start_wrapper(data="/System/Library/Fonts/KohinoorGujarati.ttc") at threads.c:1308:8 [opt]
frame #17: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #18: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #5, name = 'Timer-Scheduler'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe872372c00) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe872372c00, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x000000010592236f xammac_tests`mono_w32handle_timedwait_signal_handle at mono-coop-mutex.h:105:2 [opt]
frame #5: 0x0000000105922335 xammac_tests`mono_w32handle_timedwait_signal_handle [inlined] mono_w32handle_timedwait_signal_naked(cond=, mutex=, timeout=2941, poll=0, alerted=0x00007000060a6218) at w32handle.c:652:9 [opt]
frame #6: 0x0000000105922335 xammac_tests`mono_w32handle_timedwait_signal_handle(handle_data=, timeout=2941, poll=0, alerted=0x00007000060a6218) at w32handle.c:767:8 [opt]
frame #7: 0x0000000105922226 xammac_tests`mono_w32handle_wait_one(handle=, timeout=2941, alertable=) at w32handle.c:0 [opt]
frame #8: 0x0000000105922497 xammac_tests`mono_w32handle_wait_multiple(handles=0x00007000060a6998, nhandles=1, waitall=, timeout=2941, alertable=, error=0x00007000060a6888) at w32handle.c:1002:10 [opt]
frame #9: 0x000000010590e390 xammac_tests`ves_icall_System_Threading_WaitHandle_Wait_internal(handles=, numhandles=1, waitall=, timeout=2941, error=0x00007000060a6888) at threads.c:2314:9 [opt]
frame #10: 0x0000000105866448 xammac_tests`ves_icall_System_Threading_WaitHandle_Wait_internal_raw(a0=0x00007000060a6998, a1=1, a2='\0', a3=2941) at icall-def.h:1100:1 [opt]
frame #11: 0x000000010e6c0529
frame #12: 0x000000010e6c0193
frame #13: 0x000000010c01efe8
frame #14: 0x000000010c01e60b
frame #15: 0x0000000105787a13 xammac_tests`mono_jit_runtime_invoke(method=, obj=, params=0x00007000060a6f58, exc=, error=) at mini-runtime.c:3217:12 [opt]
frame #16: 0x00000001058bc0b8 xammac_tests`mono_runtime_invoke_checked [inlined] do_runtime_invoke(method=0x00007fe873039588, obj=0x00000001081bd668, params=0x00007000060a6f58, exc=0x0000000000000000, error=0x00007000060a6ef0) at object.c:3052:11 [opt]
frame #17: 0x00000001058bc082 xammac_tests`mono_runtime_invoke_checked(method=0x00007fe873039588, obj=0x00000001081bd668, params=0x00007000060a6f58, error=0x00007000060a6ef0) at object.c:3220:9 [opt]
frame #18: 0x00000001058c2afd xammac_tests`mono_runtime_delegate_try_invoke(delegate=0x00000001081bd668, params=0x00007000060a6f58, exc=0x0000000000000000, error=0x00007000060a6ef0) at object.c:4438:7 [opt]
frame #19: 0x0000000105914db7 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1255:3 [opt]
frame #20: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x00006000009cbb40) at threads.c:1308:8 [opt]
frame #21: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #22: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #6, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe871355e00) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe871355e00, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x00006000009e9840) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #7, name = 'Thread Pool I/O Selector'
frame #0: 0x00007ff80c303e4a libsystem_kernel.dylib`__select + 10
frame #1: 0x0000000105986bc2 xammac_tests`mono_poll(ufds=0x00007fe871844d00, nfds=1, timeout=) at mono-poll.c:114:13 [opt]
frame #2: 0x00000001059053ac xammac_tests`poll_event_wait(callback=(xammac_tests`wait_callback at threadpool-io.c:264), user_data=0x0000600003fa8be0) at threadpool-io-poll.c:153:10 [opt]
frame #3: 0x0000000105904e17 xammac_tests`selector_thread(data=) at threadpool-io.c:460:9 [opt]
frame #4: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #5: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x00006000009e8380) at threads.c:1308:8 [opt]
frame #6: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #7: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #8, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe872875a00) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe872875a00, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x000060000099b540) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #9, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe8724b5c00) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe8724b5c00, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x00006000009c8b40) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #10, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe87122de00) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe87122de00, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data="arrow.up.backward.and.arrow.down.forward") at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #11, name = 'com.apple.NSURLConnectionLoader'
frame #0: 0x00007ff80c2fbaba libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007ff80c2fbe2b libsystem_kernel.dylib`mach_msg + 59
frame #2: 0x00007ff80c3ffaf2 CoreFoundation`__CFRunLoopServiceMachPort + 319
frame #3: 0x00007ff80c3fe1cb CoreFoundation`__CFRunLoopRun + 1325
frame #4: 0x00007ff80c3fd5dd CoreFoundation`CFRunLoopRunSpecific + 563
frame #5: 0x00007ff810ffa6b2 CFNetwork`___lldb_unnamed_symbol11589$$CFNetwork + 437
frame #6: 0x00007ff80d25d2d9 Foundation`__NSThread__start__ + 1025
frame #7: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #8: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #12, name = 'com.apple.CFSocket.private'
frame #0: 0x00007ff80c303e4a libsystem_kernel.dylib`__select + 10
frame #1: 0x00007ff80c426ecd CoreFoundation`__CFSocketManager + 630
frame #2: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #3: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #13, name = 'com.apple.coreaudio.AQClient'
frame #0: 0x00007ff80c2fbaba libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007ff80c2fbe2b libsystem_kernel.dylib`mach_msg + 59
frame #2: 0x00007ff80c3ffaf2 CoreFoundation`__CFRunLoopServiceMachPort + 319
frame #3: 0x00007ff80c3fe1cb CoreFoundation`__CFRunLoopRun + 1325
frame #4: 0x00007ff80c3fd5dd CoreFoundation`CFRunLoopRunSpecific + 563
frame #5: 0x00007ff819ccd0bd AudioToolbox`CADeprecated::GenericRunLoopThread::Entry(void*) + 157
frame #6: 0x00007ff818c4d067 libAudioToolboxUtility.dylib`CADeprecated::CAPThread::Entry(CADeprecated::CAPThread*) + 77
frame #7: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #8: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #14
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff814dc21c0 caulk`caulk::mach::semaphore::wait_or_error() + 16
frame #2: 0x00007ff814da908a caulk`caulk::concurrent::details::worker_thread::run() + 36
frame #3: 0x00007ff814da8d4e caulk`void* caulk::thread_proxy > >(void*) + 41
frame #4: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #5: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #15, name = 'com.apple.coremedia.asyncio'
frame #0: 0x00007ff80c2fe506 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007ff80c338a69 libsystem_pthread.dylib`_pthread_cond_wait + 1224
frame #2: 0x00007ff814de9180 CoreMedia`WaitOnCondition + 11
frame #3: 0x00007ff814dd4bc7 CoreMedia`FigSemaphoreWaitRelative + 145
frame #4: 0x00007ff819019600 MediaToolbox`___lldb_unnamed_symbol753$$MediaToolbox + 428
frame #5: 0x00007ff814de7cd0 CoreMedia`figThreadMain + 276
frame #6: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #7: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #16
frame #0: 0x00007ff80c2fbaba libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007ff80c2fbe2b libsystem_kernel.dylib`mach_msg + 59
frame #2: 0x00007ff822e4210a CoreMIDI`XServerMachPort::ReceiveMessage(int&, void*, int&) + 94
frame #3: 0x00007ff822e72991 CoreMIDI`MIDIProcess::MIDIInPortThread::Run() + 105
frame #4: 0x00007ff822e591a0 CoreMIDI`XThread::RunHelper(void*) + 10
frame #5: 0x00007ff822e5a3f3 CoreMIDI`CAPThread::Entry(CAPThread*) + 77
frame #6: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #7: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #17, name = 'tid_1f11f'
frame #0: 0x00007ff80c2fbaba libsystem_kernel.dylib`mach_msg_trap + 10
frame #1: 0x00007ff80c2fbe2b libsystem_kernel.dylib`mach_msg + 59
frame #2: 0x00007ff80c3ffaf2 CoreFoundation`__CFRunLoopServiceMachPort + 319
frame #3: 0x00007ff80c3fe1cb CoreFoundation`__CFRunLoopRun + 1325
frame #4: 0x00007ff80c3fd5dd CoreFoundation`CFRunLoopRunSpecific + 563
frame #5: 0x00007ff810ffa6b2 CFNetwork`___lldb_unnamed_symbol11589$$CFNetwork + 437
frame #6: 0x00007ff80d25d2d9 Foundation`__NSThread__start__ + 1025
frame #7: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #8: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #18, name = 'JavaScriptCore bmalloc scavenger'
frame #0: 0x00007ff80c2fe506 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007ff80c338a69 libsystem_pthread.dylib`_pthread_cond_wait + 1224
frame #2: 0x00007ff80c297ec2 libc++.1.dylib`std::__1::condition_variable::wait(std::__1::unique_lock&) + 18
frame #3: 0x00007ff825a51695 JavaScriptCore`void std::__1::condition_variable_any::wait >(std::__1::unique_lock&) + 85
frame #4: 0x00007ff825a55e3b JavaScriptCore`bmalloc::Scavenger::threadRunLoop() + 443
frame #5: 0x00007ff825a55969 JavaScriptCore`bmalloc::Scavenger::threadEntryPoint(bmalloc::Scavenger*) + 9
frame #6: 0x00007ff825a57017 JavaScriptCore`void* std::__1::__thread_proxy >, void (*)(bmalloc::Scavenger*), bmalloc::Scavenger*> >(void*) + 39
frame #7: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #8: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #19, name = 'CVDisplayLink'
frame #0: 0x00007ff80c2fe506 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007ff80c338a69 libsystem_pthread.dylib`_pthread_cond_wait + 1224
frame #2: 0x00007ff813b7d9fc CoreVideo`CVDisplayLink::runIOThread() + 760
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #20, name = 'CVDisplayLink'
frame #0: 0x00007ff80c2fe506 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007ff80c338a69 libsystem_pthread.dylib`_pthread_cond_wait + 1224
frame #2: 0x00007ff813b7d9fc CoreVideo`CVDisplayLink::runIOThread() + 760
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #21, name = 'CVDisplayLink'
frame #0: 0x00007ff80c2fe506 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007ff80c338a69 libsystem_pthread.dylib`_pthread_cond_wait + 1224
frame #2: 0x00007ff813b7d9fc CoreVideo`CVDisplayLink::runIOThread() + 760
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #22
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #23
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #24
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #25
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #26
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #27
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #28
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #29
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #30
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #31
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #32
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00007ff91eeeaba3 ModelIO`___lldb_unnamed_symbol14259$$ModelIO + 283
frame #2: 0x00007ff91eeeaa83 ModelIO`___lldb_unnamed_symbol14258$$ModelIO + 9
frame #3: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #4: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #33, name = 'tid_9107'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe8712b0c00) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe8712b0c00, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105992ac0 xammac_tests`mono_thread_info_sleep [inlined] sleep_interruptable(ms=, alerted=0x00007000062a9eb4) at mono-threads.c:0 [opt]
frame #5: 0x000000010599290c xammac_tests`mono_thread_info_sleep(ms=, alerted=0x00007000062a9eb4) at mono-threads.c:1673:10 [opt]
frame #6: 0x00000001059082d3 xammac_tests`monitor_thread(unused=) at threadpool-worker-default.c:728:8 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x00006000007018c0) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #34, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe8725b5600) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe8725b5600, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x0000600000700940) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #35, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe87139a000) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe87139a000, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x0000600000701480) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #36, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe871117000) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe871117000, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x0000600000700540) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #37, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe871282400) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe871282400, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x000060000073ea40) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #38, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe8730c3200) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe8730c3200, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x000060000073ebc0) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #39, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe8731a5a00) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe8731a5a00, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x000060000073e700) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #40, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe87306a800) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe87306a800, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x000060000073e9c0) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #41, name = 'Thread Pool Worker'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe872cf1600) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cee1 xammac_tests`mono_threads_exit_gc_safe_region_unbalanced_internal(cookie=0x00007fe872cf1600, stackdata=) at mono-threads-coop.c:391:3 [opt]
frame #4: 0x0000000105908b3d xammac_tests`worker_thread at mono-coop-semaphore.h:57:2 [opt]
frame #5: 0x0000000105908b1c xammac_tests`worker_thread at threadpool-worker-default.c:388:11 [opt]
frame #6: 0x0000000105908903 xammac_tests`worker_thread(unused=) at threadpool-worker-default.c:490:29 [opt]
frame #7: 0x0000000105914cc3 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1233:3 [opt]
frame #8: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x00006000004ab540) at threads.c:1308:8 [opt]
frame #9: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #10: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #42, name = 'tid_8e17'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x00000001059904f9 xammac_tests`mono_os_sem_timedwait [inlined] mono_os_sem_wait at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x00000001059904e4 xammac_tests`mono_os_sem_timedwait(sem=0x0000000105c77094, timeout_ms=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:103:32 [opt]
frame #3: 0x0000000105990045 xammac_tests`mono_threads_wait_pending_operations at mono-threads.c:319:8 [opt]
frame #4: 0x00000001058ed24e xammac_tests`sgen_client_stop_world at sgen-stw.c:306:3 [opt]
frame #5: 0x00000001058ed16c xammac_tests`sgen_client_stop_world(generation=1, serial_collection=1) at sgen-stw.c:124:2 [opt]
frame #6: 0x00000001059414b6 xammac_tests`sgen_stop_world(generation=1, serial_collection=1) at sgen-gc.c:3871:2 [opt]
frame #7: 0x000000010593e0b4 xammac_tests`sgen_perform_collection [inlined] sgen_perform_collection_inner(requested_size=, generation_to_collect=, reason=, forced_serial=, stw=) at sgen-gc.c:2566:3 [opt]
frame #8: 0x000000010593e055 xammac_tests`sgen_perform_collection(requested_size=0, generation_to_collect=1, reason="user request", forced_serial=1, stw=1) at sgen-gc.c:2679:2 [opt]
frame #9: 0x000000010593f313 xammac_tests`sgen_gc_collect(generation=1) at sgen-gc.c:3132:2 [opt]
frame #10: 0x00000001058e5ba6 xammac_tests`mono_gc_collect(generation=) at sgen-mono.c:2565:2 [opt]
frame #11: 0x000000011035cc18
frame #12: 0x000000010c01e60b
frame #13: 0x0000000105787a13 xammac_tests`mono_jit_runtime_invoke(method=, obj=, params=0x000070000b42af58, exc=, error=) at mini-runtime.c:3217:12 [opt]
frame #14: 0x00000001058bc0b8 xammac_tests`mono_runtime_invoke_checked [inlined] do_runtime_invoke(method=0x00007fe873039588, obj=0x0000000108006ff8, params=0x000070000b42af58, exc=0x0000000000000000, error=0x000070000b42aef0) at object.c:3052:11 [opt]
frame #15: 0x00000001058bc082 xammac_tests`mono_runtime_invoke_checked(method=0x00007fe873039588, obj=0x0000000108006ff8, params=0x000070000b42af58, error=0x000070000b42aef0) at object.c:3220:9 [opt]
frame #16: 0x00000001058c2afd xammac_tests`mono_runtime_delegate_try_invoke(delegate=0x0000000108006ff8, params=0x000070000b42af58, exc=0x0000000000000000, error=0x000070000b42aef0) at object.c:4438:7 [opt]
frame #17: 0x0000000105914db7 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1255:3 [opt]
frame #18: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x000060000073e0c0) at threads.c:1308:8 [opt]
frame #19: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #20: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #43, name = 'tid_29913'
frame #0: 0x00007ff80c2fbaf6 libsystem_kernel.dylib`semaphore_wait_trap + 10
frame #1: 0x000000010598fe98 xammac_tests`mono_thread_info_wait_for_resume [inlined] mono_os_sem_wait(sem=, flags=MONO_SEM_FLAGS_NONE) at mono-os-semaphore.h:84:8 [opt]
frame #2: 0x000000010598fe89 xammac_tests`mono_thread_info_wait_for_resume(info=0x00007fe8710c2600) at mono-threads.c:233:8 [opt]
frame #3: 0x000000010598cbc0 xammac_tests`mono_threads_state_poll_with_info(info=0x00007fe8710c2600) at mono-threads-coop.c:149:3 [opt]
frame #4: 0x000000010598cdae xammac_tests`mono_threads_enter_gc_safe_region_unbalanced_with_info(info=0x00007fe8710c2600, stackdata=) at mono-threads-coop.c:328:3 [opt]
frame #5: 0x00000001058bb686 xammac_tests`mono_gchandle_get_target(gchandle=) at external-only.c:88:2 [opt]
frame #6: 0x000000010568c4df xammac_tests`xamarin_gchandle_get_target(handle=0x000000000005c473) at runtime.m:2955:9
frame #7: 0x000000010568f025 xammac_tests`xamarin_switch_gchandle(self=0x00006000116dacc0, to_weak=true) at runtime.m:1767:19
frame #8: 0x0000000105691f44 xammac_tests`xamarin_release_trampoline(self=0x00006000116dacc0, sel="release") at trampolines.m:709:3
frame #9: 0x0000000105a7b7ad xammac_tests`-[MonoTouchFixtures_ObjCRuntime_ToggleRefRetainDeadlockTest_CustomObject release] + 29
frame #10: 0x0000000109b57356
frame #11: 0x000000010c01e60b
frame #12: 0x0000000105787a13 xammac_tests`mono_jit_runtime_invoke(method=, obj=, params=0x000070000b62df58, exc=, error=) at mini-runtime.c:3217:12 [opt]
frame #13: 0x00000001058bc0b8 xammac_tests`mono_runtime_invoke_checked [inlined] do_runtime_invoke(method=0x00007fe873039588, obj=0x0000000108007208, params=0x000070000b62df58, exc=0x0000000000000000, error=0x000070000b62def0) at object.c:3052:11 [opt]
frame #14: 0x00000001058bc082 xammac_tests`mono_runtime_invoke_checked(method=0x00007fe873039588, obj=0x0000000108007208, params=0x000070000b62df58, error=0x000070000b62def0) at object.c:3220:9 [opt]
frame #15: 0x00000001058c2afd xammac_tests`mono_runtime_delegate_try_invoke(delegate=0x0000000108007208, params=0x000070000b62df58, exc=0x0000000000000000, error=0x000070000b62def0) at object.c:4438:7 [opt]
frame #16: 0x0000000105914db7 xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1255:3 [opt]
frame #17: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x0000600000701c00) at threads.c:1308:8 [opt]
frame #18: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #19: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #44, name = 'tid_2120b'
frame #0: 0x00007ff80c2fdcf2 libsystem_kernel.dylib`__psynch_mutexwait + 10
frame #1: 0x00007ff80c335e8f libsystem_pthread.dylib`_pthread_mutex_firstfit_lock_wait + 76
frame #2: 0x00007ff80c333d58 libsystem_pthread.dylib`_pthread_mutex_firstfit_lock_slow + 204
frame #3: 0x0000000105691f00 xammac_tests`xamarin_release_trampoline(self=0x0000600011c19e20, sel="release") at trampolines.m:694:2
frame #4: 0x0000000105a7b7ad xammac_tests`-[MonoTouchFixtures_ObjCRuntime_ToggleRefRetainDeadlockTest_CustomObject release] + 29
frame #5: 0x00007ff80c1d319f libobjc.A.dylib`AutoreleasePoolPage::releaseUntil(objc_object**) + 167
frame #6: 0x00007ff80c1d0160 libobjc.A.dylib`objc_autoreleasePoolPop + 161
frame #7: 0x00007ff80c3c102c CoreFoundation`_CFAutoreleasePoolPop + 22
frame #8: 0x00007ff80d237f68 Foundation`-[NSAutoreleasePool drain] + 133
frame #9: 0x0000000105699c97 xammac_tests`xamarin_thread_finish(user_data=0x0000000000000000) at monovm-bridge.m:281:3
frame #10: 0x0000000105699769 xammac_tests`thread_end(prof=0x0000000105c60ec0, tid=123145495449600) at monovm-bridge.m:297:2
frame #11: 0x00000001058d13ad xammac_tests`mono_profiler_raise_thread_stopped(tid=123145495449600) at profiler-events.h:105:1 [opt]
frame #12: 0x000000010590c8eb xammac_tests`mono_thread_detach_internal(thread=0x000000010c67dc18) at threads.c:1047:2 [opt]
frame #13: 0x0000000105914ccb xammac_tests`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=) at threads.c:1289:2 [opt]
frame #14: 0x0000000105914b0e xammac_tests`start_wrapper(data=0x000060000073dbc0) at threads.c:1308:8 [opt]
frame #15: 0x00007ff80c3384f4 libsystem_pthread.dylib`_pthread_start + 125
frame #16: 0x00007ff80c33400f libsystem_pthread.dylib`thread_start + 15
thread #45
frame #0: 0x00007ff80c333fec libsystem_pthread.dylib`start_wqthread

Analysis:

* Thread 44 is trying to lock `refcount_mutex`.
* Thread 43 has the `refcount_mutex` lock, and is waiting for the GC to complete.
* Thread 42 is the GC trying to stop the world, and waiting for something to happen on another thread. I'm not sure what though (as far as I can tell it shouldn't be anything from thread 43 or 44).

[execute-Mac_Modern-20220325_175425.txt](https://github.com/xamarin/xamarin-macios/files/8360115/execute-Mac_Modern-20220325_175425.txt)