[M3devel] WeakRef mechanism alive and well? cm3-cvshead

[Dragiša Durić]

And not only that, their stackbase is also set to NIL, meaning their
stack is not regarded in any way during future collections - meaning all
local variables are forgotten once apply method returns.

That way, "spuriousness"  is not an issue, once thread returns?

dd

On Thu, 2008-03-13 at 09:46 -0400, Tony Hosking wrote:
> They should get unlinked from the global ring.
> 
> Antony Hosking | Associate Professor | Computer Science | Purdue
> University
> 305 N. University Street | West Lafayette | IN 47907 | USA
> Office +1 765 494 6001 | Mobile +1 765 427 5484
> 
> 
> 
> 
> 
> On Mar 13, 2008, at 6:16 AM, Dragiša Durić wrote:
> 
> > What happens to thread stacks once threads are Join-ed?
> > 
> > dd
> > 
> > On Wed, 2008-03-12 at 11:12 -0400, Tony Hosking wrote:
> > > This is probably a result of conservatism for references from
> > > thread
> > > stacks which results in spurious retention.  It may be necessary
> > > to be
> > > more careful about what references are held on the stack in the
> > > threads implementation (and elsewhere in your code).  Until we
> > > diagnose the place where objects are being retained it will be
> > > hard to
> > > pinpoint.  You should realize that weak refs are a problem in many
> > > language implementations, not just Modula-3.  I look forward to
> > > hearing more definitively from you.
> > > 
> > > Antony Hosking | Associate Professor | Computer Science | Purdue
> > > University
> > > 305 N. University Street | West Lafayette | IN 47907 | USA
> > > Office +1 765 494 6001 | Mobile +1 765 427 5484
> > > 
> > > 
> > > 
> > > 
> > > 
> > > On Mar 12, 2008, at 4:21 AM, Dragiša Durić wrote:
> > > 
> > > > Problem in my case can be thoroughness of GC... Because it's
> > > > linked
> > > > list of WeakRef-ed objects, it's always first element in list to
> > > > become
> > > > unreachable first - all others are reachable at least through
> > > > previous
> > > > (in list) WeakRef-ed object. So, behaviour I have observed can
> > > > be
> > > > because of some thousands of freeable objects, that one is
> > > > missed
> > > > too
> > > > often.
> > > > 
> > > > I have other object being cleaned and counted... There also
> > > > cleanup
> > > > invocation looks like it's lagging too much. I'll come with
> > > > numbers
> > > > after I have more tests.
> > > > 
> > > > dd
> > > > 
> > > > On Tue, 2008-03-11 at 09:50 -0400, Tony Hosking wrote:
> > > > > Sounds like we need some sort of testcase.  Would you be able
> > > > > to
> > > > > devise one?  It will be hard to make it deterministic, but at
> > > > > least we
> > > > > should see a non-zero cleanup count.
> > > > > 
> > > > > Antony Hosking | Associate Professor | Computer Science |
> > > > > Purdue
> > > > > University
> > > > > 305 N. University Street | West Lafayette | IN 47907 | USA
> > > > > Office +1 765 494 6001 | Mobile +1 765 427 5484
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > > On Mar 11, 2008, at 4:03 AM, Dragiša Durić wrote:
> > > > > 
> > > > > > I have single linked list that I use to send messages to
> > > > > > many
> > > > > > threads.
> > > > > > It's end is locked for addition, and current end is given to
> > > > > > each
> > > > > > new
> > > > > > client connecting. This way, all client are going towards
> > > > > > end of
> > > > > > the
> > > > > > list so it's head becomes unreferenced and goes away by GC.
> > > > > > 
> > > > > > Except it does not.
> > > > > > 
> > > > > > I've added WeakRef cleanup and sequential id's so I can
> > > > > > record
> > > > > > maximum
> > > > > > freed id for checking. No single cleanup happens.
> > > > > > 
> > > > > > I'll cross check my code and count my references from
> > > > > > application
> > > > > > side,
> > > > > > but maybe someone else has similar problems?
> > > > > > 
> > > > > > dd
> > > > > > -- 
> > > > > > Dragiša Durić <dragisha at m3w.org>
> > > > > > 
> > > > > 
> > > > -- 
> > > > Dragiša Durić <dragisha at m3w.org>
> > > > 
> > > 
> > > 
> > -- 
> > Dragiša Durić <dragisha at m3w.org>
> > 
> 
> 
-- 
Dragiša Durić <dragisha at m3w.org>