30 Dec
2009
30 Dec
'09
6:56 p.m.
Hi Rob,
Thanks for your work on jscript. Unfortunately fixing Valgrind on
jscript is not going to be easy. Most of your fixes are good, except
clear_global part and "jscript: Fix a circular reference caused by
object and function objects being able to have properties that are
objects and functions." patch. I've sent a test showing that Windows
doesn't do that. To fix it properly we need to implement a garbage
collector. I've designed it in the very early days of jscript, but I
never had time to implement it.
Thanks,
Jacek
31 Dec
31 Dec
12:17 p.m.
New subject: [3/4] jscript: Fix various memory and reference count leaks.
2009/12/30 Jacek Caban <jacek(a)codeweavers.com>om>:
Hi Rob,
Thanks for your work on jscript. Unfortunately fixing Valgrind on jscript is
not going to be easy. Most of your fixes are good, except clear_global part
and "jscript: Fix a circular reference caused by object and function objects
being able to have properties that are objects and functions." patch. I've
sent a test showing that Windows doesn't do that.
I've resent the memory leak patch without the clear_global part.
To fix it properly we need
to implement a garbage collector. I've designed it in the very early days of
jscript, but I never had time to implement it.
That sounds like an excellent piece of work for someone interested in
algorithms as opposed to the usual bug fixing. I don't think I have
the time to follow through on this myself at the moment.
I can see how this would work for solving the general problem of
circular reference counts in jscript. However, I don't see how this
helps for managing the lifetime of global objects. It seems that
either the global constructors have state in which case they need to
be around for as long as the script context is, while not holding a
reference to the script context to avoid preventing it from dying, or
they don't have any state in which case they can be constructed lazily
and destroyed when the last reference is removed.
Thanks,
--
Rob Shearman
3:42 p.m.
New subject: [3/4] jscript: Fix various memory and reference count leaks.
On 12/31/09 1:17 PM, Rob Shearman wrote:
The general idea is that script_ctx_t structure is treated just like
other objects by garbage collectors. This way, if there are no
references stored outside script engine, as soon as engine is closed, it
will be released because all its references will be circular.
script_ctx_t will have to be treated a bit differently than regular
objects in practice, but it's an implementation detail.
Thanks,
Jacek
2009/12/30 Jacek Caban<jacek(a)codeweavers.com>om>:
Thanks.
Hi Rob,
Thanks for your work on jscript. Unfortunately fixing Valgrind on jscript is
not going to be easy. Most of your fixes are good, except clear_global part
and "jscript: Fix a circular reference caused by object and function objects
being able to have properties that are objects and functions." patch. I've
sent a test showing that Windows doesn't do that.
I've resent the memory leak patch without the clear_global part.
To fix it
properly we need
to implement a garbage collector. I've designed it in the very early days of
jscript, but I never had time to implement it.
That sounds like an excellent piece of work for someone interested in
algorithms as opposed to the usual bug fixing. I don't think I have
the time to follow through on this myself at the moment.
I can see how this would work for solving the general problem of
circular reference counts in jscript. However, I don't see how this
helps for managing the lifetime of global objects. It seems that
either the global constructors have state in which case they need to
be around for as long as the script context is, while not holding a
reference to the script context to avoid preventing it from dying, or
they don't have any state in which case they can be constructed lazily
and destroyed when the last reference is removed.
5251
days inactive
5252
days old
2 comments
2 participants
participants (2)
-
Jacek Caban -
Rob Shearman