named can crash under udp load on macos
from the tail of named.run:
23-Jan-2019 14:24:05.178 query client=0x7fac609c9600 thread=0x700000b93000 (008510.test.example/A): query_gotanswer: unexpected error: not enough free resources
23-Jan-2019 14:24:05.178 socket: file descriptor exceeds limit (4096/4096)
23-Jan-2019 14:24:05.178 socket: file descriptor exceeds limit (4096/4096)
23-Jan-2019 14:24:05.179 socket: file descriptor exceeds limit (4096/4096)
23-Jan-2019 14:24:05.179 query client=0x7fac638f2000 thread=0x700000787000 (075162.test.example/A): query_gotanswer: unexpected error: not enough free resources
23-Jan-2019 14:24:05.179 query client=0x7fac622cdc00 thread=0x700000b93000 (073811.test.example/A): query_gotanswer: unexpected error: not enough free resources
23-Jan-2019 14:24:05.180 socket.c:2696: INSIST(((sock->send_list).head == ((void*)0))) failed, back trace
23-Jan-2019 14:24:05.180 #0 0x10d8c2536 in isc_thread_setaffinity()+0xd509006
23-Jan-2019 14:24:05.180 #1 0x10dc14728 in isc_thread_setaffinity()+0xd85b1f8
23-Jan-2019 14:24:05.180 #2 0x10dc5d7a1 in isc_thread_setaffinity()+0xd8a4271
23-Jan-2019 14:24:05.180 #3 0x10d9b4a89 in isc_thread_setaffinity()+0xd5fb559
23-Jan-2019 14:24:05.180 #4 0x10d9b37e7 in isc_thread_setaffinity()+0xd5fa2b7
23-Jan-2019 14:24:05.180 #5 0x10d9b2b92 in isc_thread_setaffinity()+0xd5f9662
23-Jan-2019 14:24:05.180 #6 0x10dc4d769 in isc_thread_setaffinity()+0xd894239
23-Jan-2019 14:24:05.180 #7 0x10dc494f7 in isc_thread_setaffinity()+0xd88ffc7
23-Jan-2019 14:24:05.180 #8 0x7fff5b92b305 in isc_thread_setaffinity()+0x7ffe5b571dd5
23-Jan-2019 14:24:05.180 #9 0x7fff5b92e26f in isc_thread_setaffinity()+0x7ffe5b574d3f
23-Jan-2019 14:24:05.180 #10 0x7fff5b92a415 in isc_thread_setaffinity()+0x7ffe5b570ee5
23-Jan-2019 14:24:05.180 exiting (due to assertion failure)from the crash report in Console.app:
Thread 6 Crashed:
0 libsystem_kernel.dylib 0x00007fff6a00b23e __pthread_kill + 10
1 libsystem_pthread.dylib 0x00007fff6a0c1c1c pthread_kill + 285
2 libsystem_c.dylib 0x00007fff69f741c9 abort + 127
3 named 0x000000010007ba91 assertion_failed + 497
4 named 0x000000010025042a isc_assertion_failed + 10 (assertions.c:51)
5 named 0x0000000100278103 isc_socket_close + 467 (socket.c:2697)
6 named 0x00000001001036dd deactivate_dispsocket + 269 (dispatch.c:840)
7 named 0x0000000100102bb6 udp_recv + 342 (dispatch.c:1075)
8 named 0x000000010026ce4d run + 1213 (task.c:1128)
9 libsystem_pthread.dylib 0x00007fff6a0bf305 _pthread_body + 126
10 libsystem_pthread.dylib 0x00007fff6a0c226f _pthread_start + 70
11 libsystem_pthread.dylib 0x00007fff6a0be415 thread_start + 13