nng: Deadlock in nng_close(socket)

Describe the bug I’m hitting a deadlock in nng_close(socket) once every ~ 1000 runs of my unit test.

Expected behavior Calling nng_close(socket) should complete in a timely manner

Actual Behavior nng_close(socket) deadlocks

To Reproduce My unit test is very simple. I’m creating a pair0 socket and have a server and client talk through it via ipc:// aio. All works as expected only that very rarely I see a deadlock when tearing-down the unit test. Essentially, my main thread’s callstack looks like:

nni_sock_shutdown(nni_socket * sock) Line 777	C
nni_sock_close(nni_socket * s) Line 804	C
nng_close(nng_socket_s s) Line 46	C

while one of the nng worker threads is stuck doing:

nni_task_wait(nni_task * task) Line 205	C
nni_aio_wait(nng_aio *) Line 315	C
nni_aio_stop(nng_aio * aio) Line 221	C
pipe_destroy(void * arg) Line 77	C
reap_worker(void * unused) Line 58	C
nni_thr_wrap(void * arg) Line 96	C
nni_plat_thr_main(void * arg) Line 330	C

** Environment Details **

• NNG version: 1.5.2
• Operating system and version: Windows 11
• Compiler and language used: MSVC 19.29.30137.0
• Static library