gcc 4.8.5 局部 static string 线程不安全导致core

[eddie74748]

先贴一下core调用栈：

#0 0x00007f6ae4b511f7 in raise () from /lib64/libc.so.6
#1 0x00007f6ae4b528e8 in abort () from /lib64/libc.so.6
#2 0x00007f6ae5457ac5 in __gnu_cxx::__verbose_terminate_handler() () from /lib64/libstdc++.so.6
#3 0x00007f6ae5455a36 in ?? () from /lib64/libstdc++.so.6
#4 0x00007f6ae5455a63 in std::terminate() () from /lib64/libstdc++.so.6
#5 0x00007f6ae5455c83 in __cxa_throw () from /lib64/libstdc++.so.6
#6 0x00007f6ae545621d in operator new(unsigned long) () from /lib64/libstdc++.so.6
#7 0x00007f6ae54b4cf9 in std::string::_Rep::_S_create(unsigned long, unsigned long, std::allocator const&) ()
from /lib64/libstdc++.so.6
#8 0x00007f6ae54b590b in std::string::_Rep::_M_clone(std::allocator const&, unsigned long) () from /lib64/libstdc++.so.6
#9 0x00007f6ae54b5fdc in std::basic_string<char, std::char_traits, std::allocator >::basic_string(std::string const&)
() from /lib64/libstdc++.so.6
#10 0x00007f6ae1aff704 in unknown_span_name () at /usr/local/src/game_service/trunk/brpc/src/brpc/span.cpp:144
#11 brpc::Span::CreateServerSpan (trace_id=2035823792, span_id=0, parent_span_id=0, base_real_us=1527748486177589)
at /usr/local/src/game_service/trunk/brpc/src/brpc/span.cpp:187
#12 0x00007f6ae1a7286c in brpc::policy::ProcessSnailRpcRequest (msg_base=0x7f6ac0064790)
at /usr/local/src/game_service/trunk/brpc/src/brpc/policy/snail_rpc_protocol.cpp:382
#13 0x00007f6ae1b15f7a in brpc::ProcessInputMessage (void_arg=)
at /usr/local/src/game_service/trunk/brpc/src/brpc/input_messenger.cpp:132
#14 0x00007f6ae19d4eea in bthread::TaskGroup::task_runner (skip_remained=)
at /usr/local/src/game_service/trunk/brpc/src/bthread/task_group.