Weak references.

[Jason House]

Jarrett Billingsley wrote:

> "Jarrett Billingsley" <kb3ctd2 at yahoo.com> wrote in message
> news:fttdej$1nfs$1 at digitalmars.com...
>> "Sean Kelly" <sean at invisibleduck.org> wrote in message
>> news:fttd02$1mp1$1 at digitalmars.com...
>>>
>>> Are these tables AAs?  And how do the weak references store their
>>> reference?
>>> The type information provided to AAs is a bit weak, and so some
>>> non-pointer
>>> data is currently still scanned by the GC.  I'm going to improve this a
>>> bit in the
>>> next Tango release, but it still won't be perfect (because the compiler
>>> doesn't
>>> provide enough info for it to be).
>>
>> In my tests I've just been doing
>>
>> auto weakref = new WeakRef!(A)(new A);
>>
>> and then checking that after doing god-knows-what to try to get it to
>> collect that instance of A, so it's not even that I'm doing anything that
>> crazy.
>>
> 
> Testing my code in Linux causes a crash in glibc's free() after the
> program
> exits.  (And the assertion still fails.)
> 
> Something really weird is happening.

Ok, my latest testing (and testing by others for configurations I don't
have) are collected in the list below.  I don't see any pattern.

tango+linux+dmd = works
tango+linux+gdc = crash in glibc
tango+windows+dmd = does not collect
tango+windows+gdc = ???
phobos+linux+dmd = works
phobos+linux+gdc = does not collect
phobos+windows+dmd = ???
phobos+windows+gdc = ???

These tests are based off the code at http://tango.pastebin.com/m10aa57b6
Note that phobos users must comment out the version=Tango line.  Any
additional tests would be appreciated.