use MCE::Shared;

   # starting the shared-manager, implicitly
   my $ca = MCE::Shared->cache( max_keys => 500 );

   # or starting early, explicitly
   MCE::Shared->start();

   # at this point, IO::FDPass is necessary for constructing
   # a shared condvar or queue, passing fd descriptor

   # ... for new socket handle made during construction
   # workers block using a socket handle for ->wait, ->timedwait
   # the shared-manager unblocks by writing to _cw_sock

   my $cv = MCE::Shared->condvar();  # _cw_sock

   # ... for new socket handles made during construction
   # workers block using socket handles for ->dequeue, ->await
   # the shared-manager unblocks by writing to _qw_sock, _aw_sock

   my $q1 = MCE::Shared->queue();  # _qw_sock
   my $q2 = MCE::Shared->queue( await => 1 );  # _aw_sock