Gdb backtrace

Hi, all
I try to understand the output from gdb

Program received signal SIGABRT, Aborted.
*** glibc detected *** /home/sys_cbo/dev/zif/bin/Debug/zifd: free(): invalid pointer: 0x00007fffac04d3d0 ***

how should i read this?
(gdb) backtrace

 #0  0x0000003015e32925 in raise () from /lib64/libc.so.6
 #1  0x0000003015e34105 in abort () from /lib64/libc.so.6
 #2  0x0000003015e70837 in __libc_message () from /lib64/libc.so.6
 #3  0x0000003015e76166 in malloc_printerr () from /lib64/libc.so.6
 #4  0x000000000050cf34 in __gnu_cxx::new_allocator<CaxMysql*>::deallocate (this=0x9305d8, __p=0x7fffac04d3d0)
     at /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../include/c++/4.4.7/ext/new_allocator.h:95
 #5  0x000000000050cab2 in std::_Deque_base<CaxMysql*, std::allocator<CaxMysql*> >::_M_deallocate_node (
     this=0x9305d8, __p=0x7fffac04d3d0)
     at /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../include/c++/4.4.7/bits/stl_deque.h:450
 #6  0x000000000050c651 in std::deque<CaxMysql*, std::allocator<CaxMysql*> >::_M_pop_back_aux (this=0x9305d8)
     at /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../include/c++/4.4.7/bits/deque.tcc:429
 #7  0x000000000050c21e in std::deque<CaxMysql*, std::allocator<CaxMysql*> >::pop_back (this=0x9305d8)
     at /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../include/c++/4.4.7/bits/stl_deque.h:1262
 #8  0x000000000050c007 in axf::queue<CaxMysql*>::pop_back (this=0x9305d8) at /home/sys_cbo/dev/common/axqueue.hpp:28
 #9  0x000000000050b9fb in mysql_con::get (this=0x9305c0) at /home/sys_cbo/dev/zif/mysql_con.cpp:41
 #10 0x00000000004d3864 in axf::TconnectionPool::getconn (this=0x932850)
     at /home/sys_cbo/dev/zif/connectionPool.cpp:49
 #11 0x000000000042cffe in CBuildhiso::BuildAuthRespHSM (this=0x7fffd002a020, spdhansw=..., spdh=..., iso8583=...,
     isoansw=
      "ISO026000050011032384481AEA18053", '0' <repeats 12 times>,  "120300081508504710361308504608155499011000645700006457000214134831323379825=12060205232301161771380000099999         ZIFTEST", ' ' <repeats 15 times>, "VALBO         000SE01100000"..., cxi=0x7fffa0011890, http_header=std::map with 10  elements = {...})
     at /home/sys_cbo/dev/zif/buildhiso.cpp:826
 #12 0x000000000049913e in Csession::buildSPDHanswer (this=0x7fffd0028a00, spdh=..., _m=
      "ISO026000050011032384481AEA18053", '0' <repeats 12 times>,  "120300081508504710361308504608155499011000645700006457000214134831323379825=12060205232301161771380000099999         ZIFTEST", ' ' <repeats 15 times>, "VALBO         000SE01100000"..., http_header=std::map with 10 elements = {...}) at  /home/sys_cbo/dev/zif/session.hpp:148
 #13 0x000000000049b9f8 in Csession::handle_incomming (this=0x7fffd0028a00) at /home/sys_cbo/dev/zif/session.hpp:439
 #14 0x00000000004d358b in boost::_mfi::mf0<void, Csession>::call<boost::shared_ptr<Csession> > (
     this=0x7fffd0027758, u=...) at /usr/local/boost/include/boost/bind/mem_fn_template.hpp:40
 #15 0x00000000004d350f in boost::_mfi::mf0<void, Csession>::operator()<boost::shared_ptr<Csession> > (
     this=0x7fffd0027758, u=...) at /usr/local/boost/include/boost/bind/mem_fn_template.hpp:55
 #16 0x00000000004d34a8 in  boost::_bi::list1<boost::_bi::value<boost::shared_ptr<Csession>  > >::operator()<boost::_mfi::mf0<void, Csession>,  boost::_bi::list0> (this=0x7fffd0027768, f=..., a=...)
     at /usr/local/boost/include/boost/bind/bind.hpp:253
 #17 0x00000000004d2fb3 in  boost::_bi::bind_t<void, boost::_mfi::mf0<void, Csession>,  boost::_bi::list1<boost::_bi::value<boost::shared_ptr<Csession>  > > >::operator() (this=0x7fffd0027758)
     at /usr/local/boost/include/boost/bind/bind_template.hpp:20
 #18 0x00000000004d2602 in  boost::detail::thread_data<boost::_bi::bind_t<void,  boost::_mfi::mf0<void, Csession>,  boost::_bi::list1<boost::_bi::value<boost::shared_ptr<Csession>  > > > >::run (this=0x7fffd00275a0)
     at /usr/local/boost/include/boost/thread/detail/thread.hpp:117
 #19 0x00000000005d6b1b in thread_proxy ()
 #20 0x00000030166079d1 in start_thread () from /lib64/libpthread.so.0
 #21 0x0000003015ee8b5d in clone () from /lib64/libc.so.6

It's a call stack. It means the stack starts at your function, thread_proxy and crashed in __gcc_cxx::new_allocator, which proceeds to raise an error, which is where it eventually stops.