Re: [PATCH] packfile: free packed_git memory when closing object store

[Junio C Hamano <gitster@pobox.com>]

Mike Hommey <mh@glandium.org> writes:

> Signed-off-by: Mike Hommey <mh@glandium.org>
> ---
>  packfile.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
>
> Note, I'm not sure this is the right place to do it.

I do not think this patch is complete, given that o->packed_git
still has a non-NULL pointer.  IIRC, close_pack() was written for
the explicit purpose of releasing resources while allowing us to
reopen with open_packed_git() on it, so with the current
arrangement, after releasing the resources held for this object
store and doing something else, you should be able to come back to
this object store and work in it again---this patch makes it harder
if not impossible to do so.

I _think_ the patch is OK if you assigned NULL to o->packed_git,
after making sure that the intention of all the callers of
close_object_store() is to declare that this object store will not
be accessed any longer during the lifetime of the process, and write
it down as the contract between the callers and this function in a
comment perhaps in packfile.h where the function is declared.

Thanks.

> diff --git a/packfile.c b/packfile.c
> index fc43a6c52c..b0cb84adda 100644
> --- a/packfile.c
> +++ b/packfile.c
> @@ -339,13 +339,16 @@ void close_pack(struct packed_git *p)
>  
>  void close_object_store(struct raw_object_store *o)
>  {
> -	struct packed_git *p;
> +	struct packed_git *p = o->packed_git;
>  
> -	for (p = o->packed_git; p; p = p->next)
> +	while (p) {
> +		struct packed_git *current = p;
>  		if (p->do_not_close)
>  			BUG("want to close pack marked 'do-not-close'");
> -		else
> -			close_pack(p);
> +		close_pack(p);
> +		p = p->next;
> +		free(current);
> +	}
>  
>  	if (o->multi_pack_index) {
>  		close_midx(o->multi_pack_index);