Thread 0x1b84 1001 samples (1-1001) priority 20 (base 20) 1001 thread_start + 15 (libsystem_pthread.dylib + 8043) [0x7ff811368f6b] 1001 _pthread_start + 125 (libsystem_pthread.dylib + 25825) [0x7ff81136d4e1] 1001 void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, void ()(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, void, system_profile_struct const&), std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, char const*, void*, std::__1::reference_wrapper<system_profile_struct> > >(void*) + 183 (LCAService + 80023) [0x108a97897] 1001 LuaLoaderThread(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, void*, system_profile_struct const&) + 126 (LCAService + 534046) [0x108b0661e] 1001 LuaRT::setSystemProfile(system_profile_struct const&) + 1216 (LCAService + 383216) [0x108ae18f0] 1001 GetArch() + 25 (LCAService + 498825) [0x108afdc89] 1001 executeExternalCommand(char const*) + 368 (LCAService + 499328) [0x108afde80] 1001 fgets + 98 (libsystem_c.dylib + 153775) [0x7ff81125c8af] 1001 __srefill1 + 24 (libsystem_c.dylib + 61288) [0x7ff811245f68] 1001 __read_nocancel + 10 (libsystem_kernel.dylib + 12826) [0x7ff81133221a] *1001 hndl_unix_scall64 + 22 (kernel + 82470) [0xffffff8000224226] *1001 unix_syscall64 + 507 (kernel + 7843115) [0xffffff800098ad2b] *1001 read_nocancel + 122 (kernel + 6783754) [0xffffff800088830a] *1001 ??? (kernel + 6783538) [0xffffff8000888232] *1001 ??? (kernel + 6802929) [0xffffff800088cdf1] *1001 ??? (kernel + 6659500) [0xffffff8000869dac] *1001 lck_mtx_sleep + 110 (kernel + 562846) [0xffffff800029969e] *1001 thread_block_reason + 199 (kernel + 642919) [0xffffff80002acf67] *1001 ??? (kernel + 651724) [0xffffff80002af1cc] *1001 machine_switch_context + 219 (kernel + 1820299) [0xffffff80003cc68b]
the stack fgets locked ,why?