Re: [Ming-dev] ming garbage collection

[strk <st...@ke...>]

I've finally implemented garbage collection in Ming.
Sorry klaus, I was too lazy to take care of Ming objects from user code..

What you have now is a Ming_collectGarbage() function that will
destroy all Ming objects. The implementation does not cover *all* ming
objects because I did not have handy code to test it on.
Currently handled: movie, movieclip, shape, jpeg, fill, input.

Robert, can you give it a try and add garbage collection support 
for the objects you still see alive after Ming_collectGarbage call ?
Verify that TRACK_ALLOCS is defined in ming_config.h and copy from
movie.c the changes in the struct, the constructor and the desctructor.

Then, when you've done with the Ming object you created call
Ming_collectGarbage().

Note that you must know what you are doing, since calling
Ming_collectGarbage() and then trying to use your objects
will result in a segfault. 

Use with care. If you're afraid, keep doing as you always did and
everything will be fine. If you can't stand 6 bytes of overhead for
each created Ming object undefine TRACK_ALLOCS in ming_config.h.

--strk;


On Mon, Apr 05, 2004 at 05:33:39PM +0200, strk wrote:
> On Mon, Apr 05, 2004 at 01:29:09PM +0200, Klaus Rechert wrote:
> > 
> > >On Sun, Apr 04, 2004 at 05:03:09PM -0000, ham...@t-... wrote:
> > >
> > >  
> > >
> > >>Now, to the subject of garbage collection:
> > >>I could imagine a setup where ming keeps a linked list of allocated objects. Every object
> > >>has a destructor, and the destructor would unlink the object from the list. So if it comes to
> > >>garbage collection, one could just walk the linked list and called all the objects' destructors
> > >>This should be a function available through the api, because otherwise we get problems with
> > >>php or perl - they build their own objects which reference the ming objects, and call the
> > >>destructors themselves
> > >>    
> > >>
> > Hi,
> > 
> > how about only "exporting" a list of Objects to the user which are 
> > safely destroyable? i still think the destruction should be transparent 
> > to the user. in some cases it isn't possible to destroy 
> > character-objects (like Fonts, Sound-stuff, video etc. ), so if the 
> > destruction isn't transparent you have to guess if your pointer is still 
> > valid.
> > 
> > The list of no more needed Character-objects could be returned by the 
> > SWFMovie_flush() method. All Character objects need refcounts then. The 
> > refcount should be incremented at somewhere SWFMovie_add() and 
> > decremented at write/complete if its safe to release the object.
> > 
> > What do you think ?
> 
> I started working on the simpler implementation.
> What I need is just a way to kill all Ming objects created so far.
> Calling Ming_cleanup() when finished working with a Movie or a set of
> Movies would ensure there are no Ming objects allocated. You know when
> you are calling Ming_cleanup() you won't try to use again the Ming
> objects previously created.
> 
> What you are proposing sounds a bit too complex to me, in 
> both user and developer terms. I'd start from the API.
> If you show me how simple would it be for the user I'm ready
> to change my mind (development cost remains though:)
> 
> 
> --strk;
> 
> 
> > 
> > Cheers
> >     Klaus