• Borneq (5/5) Aug 15 2010 Conservative garbage collection causes memory leaks. In D is added:
• Leandro Lucarella (19/25) Aug 16 2010 Unfortunately full preciseness is not possible in D, due to unions
• bearophile (6/10) Aug 16 2010 LLVM contains tools to implement precise stack tracing. Once some applic...

"Borneq" <borneq antyspam.hidden.pl> writes:

Conservative garbage collection causes memory leaks. In D is added:
http://d.puremagic.com/issues/show_bug.cgi?id=3463
This is semi precise - only the heap have type information. What type 
information has fully precise? Semi precise causes memory leaks?
This above patch is applied in official version D ? 

Leandro Lucarella <luca llucax.com.ar> writes:

Borneq, el 16 de agosto a las 07:53 me escribiste:
 Conservative garbage collection causes memory leaks. In D is added:
 http://d.puremagic.com/issues/show_bug.cgi?id=3463
 This is semi precise - only the heap have type information. What
 type information has fully precise? Semi precise causes memory
 leaks?

Unfortunately full preciseness is not possible in D, due to unions
mostly. Having a precise stack would be very hard (and probably costly,
so not very suitable for D) but having a precise static data (and a more
accurate one) maybe is possible, see bug 4650:
http://d.puremagic.com/issues/show_bug.cgi?id=4650

Memory leaks will always be possible in D, but I think if the stack is
the only part that should be scanned in conservative mode, they can
greatly be reduced.

 This above patch is applied in official version D ?

Not yet, vote up! =)

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bearophile <bearophileHUGS lycos.com> writes:

Leandro Lucarella:
 Unfortunately full preciseness is not possible in D, due to unions mostly.

But unions are not so common in D code.


  Having a precise stack would be very hard (and probably costly,
 so not very suitable for D)

LLVM contains tools to implement precise stack tracing. Once some application
is available for D2, and once a LLVM-based D2 compiler exists, I think those
tools can be used to perform experiments, to see how much costly they are, how
much precision they give, etc (even if they are not present with DMD).


 This above patch is applied in official version D ?

With the current "speed" it may take two years :-) You probably have to wait.

Bye,
bearophile