t3rmin4t0r> assume I'm setting p->next = NULL
03:03 < YuviPanda> ok?
03:03 < YuviPanda> and?
03:03 < t3rmin4t0r> this one will need for(i = 0; i < tries; i++) cas(p->next, p->next, NULL));
03:03 < t3rmin4t0r> eeks, I meant
03:03 < t3rmin4t0r> for(i = 0; i < tries && cas(p->next, p->next, NULL); i++);
03:04 < t3rmin4t0r> so that ensure I do not overwrite the write someone else did
03:05 < t3rmin4t0r> but a singly linked list is so uber complicated & painful
03:05 < t3rmin4t0r> insertions are damn easy to do without issues
03:06 < t3rmin4t0r> i = 0; do { newp->next = p->next; i++; ) while(!cas(p->next, p->next, newp->next))
03:06 < t3rmin4t0r> yeah, I meant !cas() earlier as well
03:06 < t3rmin4t0r> but deletions are a pain in the ass
03:07 < t3rmin4t0r> insertions are neat because nobody but the writing thread can write to newp->next
03:07 < t3rmin4t0r> so we never need to worry about have sync issues
03:07 < t3rmin4t0r> deletions are painful because both pointers need to be swapped at the *same* time
03:08 < t3rmin4t0r> anyway, night night
03:08 < YuviPanda> ah, so that's kinda like two atomic ones - which really should be one
03:08 < YuviPanda> t3rmin4t0r,  where does this code go to?
03:08 < t3rmin4t0r> I've got a local svn for this kind of work
03:08 < t3rmin4t0r> but eventually, it becomes part of php-apc
03:08 < YuviPanda> t3rmin4t0r, no, i mean - PHP Interpreter, APC, etc?
03:08 < YuviPanda> ah
03:08 < YuviPanda> right
03:09 < YuviPanda> t3rmin4t0r, gnite, i'lll send you a dm reminding you of that sponsorship thingy
03:09 < iwikiwi> t3rmin4t0r: (might sound dumb but) why cant you use two operations? (and not same time)
03:09 < t3rmin4t0r> yeah, alright
03:10 < t3rmin4t0r> iwikiwi: assume the list looks like 1 -> 2 -> 3 -> 4
03:10 < iwikiwi> okay, go on
03:10 < t3rmin4t0r> thread #1 tries to delete 2, thread #2 tries to delete 3
03:10 < t3rmin4t0r> 1->next = 3; #thread 1
03:10 < t3rmin4t0r> 2->next = 4; #thread 2
03:10 < iwikiwi> ah
03:11 < iwikiwi> when it should be
03:11 < iwikiwi> 3->4
03:11 < t3rmin4t0r> 1->4;
 <t3rmin4t0r> eventually
03:11 < iwikiwi> right
03:11 < t3rmin4t0r> if I can get it work for a linked list, it automatically applies to a tree
03:12 < YuviPanda> so right now, you put a lock around the entire thing you're changing so those two separate atomic ops become one atomic op (to use a
                   crude way of saying things)
03:12 < t3rmin4t0r> yup, I put a lock around *all* ops on the linked list, not just adjacent ones
03:12 < YuviPanda> while you're looking for a way to get rid of that lock and make it a singl cpu level atmic op.
03:13 < t3rmin4t0r> not really *single*, but I'd rather not prevent changes in one end of the list from slowing down changes at the other end
03:13 < t3rmin4t0r> I have a 16 cpu box here which is just wasting time on 15 cpus while one cpu is doing an operation
03:13 < YuviPanda> ah!
03:13 < nikkar> ooh yeah baby give it to me~~~
03:14 < t3rmin4t0r> anyway, tomorrow's friday!!
03:14 -!- t3rmin4t0r [~gopalv@122.178.221.31] has quit [Quit: TGIF!]