I'm actually using boost 1.35.0 When I just include boost/interprocess/sync/file_lock.hpp in a very simple programm, then I have a list of error very surprising : "member function already defined or declared" So what, is file_lock unusable in 1.35 ? It was my only hope, other boost locks don't satisfy me. I didn't see such an error in the last 6 month ML log, so I guess nobody had it yet. log : 1>c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(167) : error C2535: 'bool boost::interprocess::file_lock::timed_acquire_file_lock(boost::interprocess::file_handle_t,bool &,const boost::posix_time::ptime &)' : member function already defined or declared 1> c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(110) : see declaration of 'boost::interprocess::file_lock::timed_acquire_file_lock' 1>c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(195) : error C2535: 'bool boost::interprocess::file_lock::timed_acquire_file_lock_sharable(boost::interprocess::file_handle_t,bool &,const boost::posix_time::ptime &)' : member function already defined or declared 1> c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(138) : see declaration of 'boost::interprocess::file_lock::timed_acquire_file_lock_sharable' 1>c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(119) : error C3861: 'try_acquire_file_lock': identifier not found 1>c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(147) : error C3861: 'try_acquire_file_lock_sharable': identifier not found 1>c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(175) : error C3861: 'try_acquire_file_lock': identifier not found 1>c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(188) : error C3861: 'sleep': identifier not found 1>c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(203) : error C3861: 'try_acquire_file_lock_sharable': identifier not found 1>c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(262) : error C2039: 'timed_acquire_file_lock' : is not a member of 'boost::interprocess::detail' 1>c:\boost_tri\include\boost-1_35\boost\interprocess\sync\file_lock.hpp(298) : error C2039: 'timed_acquire_file_lock_sharable' : is not a member of 'boost::interprocess::detail'