I use boost1.52 on windows2003sp2, boost::unique_lock throw a exception, please help me. stack is: *RaiseException_CxxThrowExceptionboost::throw_exceptionboost::lock_error[e:\library\boost_1_52\boost\throw_exception.hpp：67] boost::shared_mutex::timed_lock[e:\library\boost_1_52\boost\thread\win32\shared_mutex.hpp：430]boost::shared_mutex::lock[e:\library\boost_1_52\boost\thread\win32\shared_mutex.hpp：382]boost::unique_lockboost::shared_mutex::lock[e:\library\boost_1_52\boost\thread\locks.hpp：510]* ------------------------------------------------------------------------ *bool timed_lock(boost::system_time const& wait_until){ for(;;) { state_data old_state=state; for(;;) { state_data new_state=old_state; if(new_state.shared_count || new_state.exclusive) { ++new_state.exclusive_waiting; if(!new_state.exclusive_waiting) { boost::throw_exception(boost::lock_error()); } new_state.exclusive_waiting_blocked=true; } else { new_state.exclusive=true; }*