On Fri, 17 Jun 2005, [EMAIL PROTECTED] wrote: > I'm thinking of ways to avoid the stack penalties the other proposals > involve. Could we allow only secondary threads with thread-local > variables and forked copies of globals? > > "Forked copies of globals" would mean copies of the values of > thousands of Lisp symbols. And how would the Lisp interpreter know > whether and where to look for them? It does not seem practical.
Don't make copies of the globals then, unless they are modified. If the secondary thread modifies a global, make the copy then (Copy On Write). If the primary thread modifies a global, trigger a copy for every thread of the OLD value (null op if no threads exist). The interpreter would just have to keep a hashtable of hashtables; primary key is the secondary thread ID and the secondary key is the global symbol. When a thread modifies a global, look in the HoH; if the symbol is not in there you create an entry. To get a symbol value in a thread, you do two hashtable lookups; in the primary thread there's no lookups. There should be a way that a thread can send data back to the main thread on request (the main thread asks for the data). Ted _______________________________________________ Emacs-devel mailing list Emacs-devel@gnu.org http://lists.gnu.org/mailman/listinfo/emacs-devel
