On onsdag, juli 24, 2002, at 11:33 , Dave Mitchell wrote:
> > On Wed, Jul 24, 2002 at 10:02:36PM +0200, Elizabeth Mattijsen wrote: >> - using the ": shared" attribute is _not_ a way to save memory, quite >> the >> contrary. It uses even _more_ memory than unshared. This seems >> counter-intuitive to me and may be a bug. > > The main point of :shared is not to save memory, but to allow multiple > threads access to the same data. From perlthrtut: > > Also note that under the current implementation, shared variables > use > a little more memory and are a little slower than ordinary > variables. > > Each shared var has an emptyish SV per thread which has attached magic > that allows it to access the contents of the real var. > > Dave. > > -- > "Emacs isn't a bad OS once you get used to it. > It just lacks a decent editor." > For a large amount of data :shared will save you memory, the overhead of the magic is rather small compared to large data structures :) Arthur
