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

[Dragiša Durić]

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>