On Thu, Jul 17, 2003 at 08:40:44PM -0400, Benjamin Goldberg wrote:
Actually, I'm thinking of something like the following... suppose the original code is like:
label_foo: loop body branch_address: branch label_foo
Add in the following:
e_handler_foo: .local PerlHash handlers_with_events .local int i_have_an_event handlers_with_events = .... i_have_an_event = handlers_with_events[cur_thread] unless i_have_an_event, label_foo bsr dequeue_events_and_handle_them_all branch label_foo
And then, when an event occurs, replace "branch label_foo" with "branch e_handler_foo".
When there are no events queued, for any thread, then we change "branch e_handler_foo" back into "branch label_foo", for speed.
Do we need to do this last bit explicitly? Or can we do it lazily - each time we get called to e_handler when there are no longer events, we change back that instruction.
Or is this already done this way?
Some issues related to this scheme:
1) In a highly secure mode, you don't want self modifing code. we need a way to lock down code into RO memory when security is important. A similar problem exists with modifing vtables on the fly.
2) Making that exception safe may be a problem.
3) Is parriot byte code suppose to be position independent? Having all code be PIC makes dynamic loading simpler.
4) As parriot ops are rather CISC anyway, maybe a special op that checks for events and takes one of two branches could be used here.
-- [EMAIL PROTECTED] [EMAIL PROTECTED]
