#0  0x00007ffff5a1789c in __lll_lock_wait () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007ffff5a13065 in _L_lock_858 () from /lib/x86_64-linux-gnu/libpthread.so.0
#2  0x00007ffff5a12eba in pthread_mutex_lock () from /lib/x86_64-linux-gnu/libpthread.so.0
#3  0x00007ffff7091ec7 in ibis::column::getNullMask(ibis::bitvector&) const () from /usr/local/lib/libfastbit.so.0
#4  0x00007ffff7959811 in ibis::direkte::direkte(ibis::column const*, unsigned int, unsigned int) () from /usr/local/lib/libfastbit.so.0
#5  0x00007ffff77f5713 in ibis::category::fillIndex(char const*) const () from /usr/local/lib/libfastbit.so.0
#6  0x00007ffff77f94b8 in ibis::category::prepareMembers() const () from /usr/local/lib/libfastbit.so.0
#7  0x00007ffff77ff908 in ibis::category::selectStrings(ibis::bitvector const&) const () from /usr/local/lib/libfastbit.so.0
#8  0x00007ffff769b216 in ibis::colValues::create(ibis::column const*, ibis::bitvector const&) () from /usr/local/lib/libfastbit.so.0
#9  0x00007ffff78c611c in ibis::bundle1::bundle1(ibis::query const&, int) () from /usr/local/lib/libfastbit.so.0
#10 0x00007ffff78cd60b in ibis::bundle::create(ibis::query const&, int) () from /usr/local/lib/libfastbit.so.0