Crash in mono_coop_mutex_lock while running VS for Mac

[slluis]

Steps to Reproduce

I don't have steps to reproduce. I just started VS for Mac and it crashed. It didn't crash after that.

Current Behavior

VS for Mac crashed with this error:

error: mono_coop_mutex_lock Cannot transition thread 0x70000fb36000 from STATE_BLOCKING with DO_BLOCKING

On which platforms did you notice this

[x] macOS
[ ] Linux
[ ] Windows

Version Used:

Mono 6.4.0.81 (2019-06/f55e0a671c0)

Stacktrace

Full IDE log: https://gist.github.com/slluis/9c5f2fc84bfb55461ebd69a1b68672a1
Native crash report: https://gist.github.com/slluis/b1a63cec0638fe7489b64081df92f6f6

[marek-safar]

@lambdageek are we tracking this issue already?

[lambdageek]

Haven't seen this one before.

Looks like the thread is in already in GC Safe mode when the jit info table is freed when unregistering a thread. Possibly needs a GC Unsafe transition in jit_info_table_free

Thread 30 Crashed:: tid_1612b
0   libsystem_c.dylib             	0x00007fff7d0cf766 __abort + 177
1   libsystem_c.dylib             	0x00007fff7d0cf6b5 abort + 142
2   libmonosgen-2.0.dylib         	0x0000000106d0413e mono_post_native_crash_handler + 14
3   libmonosgen-2.0.dylib         	0x0000000106c9cd8c mono_handle_native_crash + 412 (mini-exceptions.c:3357)
4   libmonosgen-2.0.dylib         	0x0000000106bf5e98 mono_sigill_signal_handler + 72 (mini-runtime.c:3247)
5   libsystem_platform.dylib      	0x00007fff7d215b5d _sigtramp + 29
6   dyld                          	0x00000001116a6b76 dyld::fastBindLazySymbol(ImageLoader**, unsigned long) + 86
7   libsystem_c.dylib             	0x00007fff7d0cf6b5 abort + 142
8   libxammac.dylib               	0x00000001030ed7f0 log_callback(char const*, char const*, char const*, int, void*) + 64
9   libmonosgen-2.0.dylib         	0x0000000106f0c6de monoeg_g_logv_nofree + 190 (goutput.c:150)
10  libmonosgen-2.0.dylib         	0x0000000106f0c792 monoeg_g_log + 130 (goutput.c:165)
11  libmonosgen-2.0.dylib         	0x0000000106f02bdc mono_threads_transition_do_blocking + 220 (mono-threads-state-machine.c:672)
12  libmonosgen-2.0.dylib         	0x0000000106f04254 mono_threads_enter_gc_safe_region_unbalanced_with_info + 132 (mono-threads-coop.c:319)
13  libmonosgen-2.0.dylib         	0x0000000106d7c236 mono_domain_lock + 54 (mono-coop-mutex.h:52)
14  libmonosgen-2.0.dylib         	0x0000000106dd4683 jit_info_table_free + 35 (jit-info.c:100)
15  libmonosgen-2.0.dylib         	0x0000000106efc169 try_free_delayed_free_items + 169 (hazard-pointer.c:373)
16  libmonosgen-2.0.dylib         	0x0000000106efefd5 unregister_thread + 85 (mono-threads.c:522)
17  libmonosgen-2.0.dylib         	0x0000000106eff930 thread_info_key_dtor + 32 (mono-threads.c:781)
18  libsystem_pthread.dylib       	0x00007fff7d21e660 _pthread_tsd_cleanup + 476
19  libsystem_pthread.dylib       	0x00007fff7d221655 _pthread_exit + 70
20  libsystem_pthread.dylib       	0x00007fff7d21e43a _pthread_wqthread_exit + 74
21  libsystem_pthread.dylib       	0x00007fff7d21d644 _pthread_wqthread + 472
22  libsystem_pthread.dylib       	0x00007fff7d21d3fd start_wqthread + 13