社区版obproxyd stop时 kill -15 会生成core文件

[enhengkang]

hi：
在调试社区版obproxy执行stop时 kill 默认以信号量15 杀掉obproxy ，等待一段时间后如果还未退出，则会有信号量9 再次kill，但是当前版本会产生core文件。测试了下企业版中同样的执行stop 则不会产生core文件
当前版本是obproxy (OceanBase 3.1.0 1) ，理论上执行stop会正常退出,请官方帮忙看下, 多谢
core文件堆栈如下
#0 0x00007fe3f8ab31f7 in raise () from /lib64/libc.so.6
#1 0x00007fe3f8ab48e8 in abort () from /lib64/libc.so.6
#2 0x0000000001795118 in _Unwind_SetGR ()
#3 0x00000000013868e2 in __gxx_personality_v0 ()
#4 0x00007fe3e5e3da14 in ?? () from /lib64/libgcc_s.so.1
#5 0x00007fe3e5e3dd64 in _Unwind_ForcedUnwind () from /lib64/libgcc_s.so.1
#6 0x00007fe3f9151240 in __pthread_unwind () from /lib64/libpthread.so.0
#7 0x00007fe3f9149865 in sigcancel_handler () from /lib64/libpthread.so.0
#8
#9 0x00007fe3f915198d in accept () from /lib64/libpthread.so.0
#10 0x00000000004ee6ed in oceanbase::obproxy::net::ObServerConnection::accept(oceanbase::obproxy::net::ObConnection*) ()
#11 0x00000000010da2ba in oceanbase::obproxy::net::ObNetAccept::do_blocking_accept() ()
#12 0x00000000010dcd28 in oceanbase::obproxy::net::ObNetAccept::accept_loop_event(int, oceanbase::obproxy::event::ObEvent*) ()
#13 0x00000000010c1101 in oceanbase::obproxy::event::ObEThread::execute() ()
#14 0x00000000004e914e in oceanbase::obproxy::event::spawn_thread_internal(void*) ()
#15 0x00007fe3f914ae25 in start_thread () from /lib64/libpthread.so.0
#16 0x00007fe3f8b7634d in clone () from /lib64/libc.so.6