I am working on multi-threading application it is dumping frequently.I could not able to analyaze the core.The core is showing like this

Core was generated by 'thread-process'.
Program terminated with signal 6, Aborted.
#0  0x00000038f4e30045 in raise () from /lib64/libc.so.6
(gdb) where
#0  0x00000038f4e30045 in raise () from /lib64/libc.so.6
#1  0x00000038f4e31ae0 in abort () from /lib64/libc.so.6
#2  0x00000038f4e681bb in __libc_message () from /lib64/libc.so.6
#3  0x00000038f4e72b96 in free () from /lib64/libc.so.6
#4  0x000000000046a137 in std::string::substr ()
#5  0x000000000042c549 in std::operator<< <char, std::char_traits<char>, std::allocator<char> > ()
#6  0x000000000042cc1d in std::operator<< <char, std::char_traits<char>, std::allocator<char> > ()
#7  0x000000000046b069 in std::string::substr ()
#8  0x000000000046c866 in std::string::substr ()
#9  0x0000000000431062 in std::operator<< <char, std::char_traits<char>, std::allocator<char> > ()
#10 0x00000038f5a062e7 in start_thread () from /lib64/libpthread.so.0
#11 0x00000038f4ece3bd in clone () from /lib64/libc.so.6