From: SASADA Koichi <ko1@...>
Date: 2013-10-04T08:52:02+09:00
Subject: [ruby-core:57645] Re: [ruby-trunk - Bug #8983][Assigned] [PATCH] GC.stat[:heap_free_num] returns number of unused slots on heap

(2013/10/03 18:29), naruse (Yui NARUSE) wrote:
> https://github.com/tmm1/ruby/compare/gc-stat-free-num.patch

One point.
> @@ -1787,6 +1791,7 @@ struct os_each_struct {
>  	else {
>  	    struct heap_slot *slot = (struct heap_slot *)(VALUE)RDATA(p)->dmark;
>  	    slot->limit--;
> +	    heap_limit--;
>  	}
>  	p = tmp;
>      }

Should not reduce heap_limit here.

> @@ -2343,6 +2348,7 @@ struct force_finalize_list {
>  	    RDATA(pp)->dmark = (void (*)(void *))(VALUE)sweep_slot;
>              pp->as.free.flags |= FL_SINGLETON; /* freeing page mark */
>          }
> +        heap_limit -= (freed_num + empty_num);
>          sweep_slot->limit = final_num;
>          unlink_heap_slot(objspace, sweep_slot);
>      }

Should set "heap_limit -= slot->limit".
This slot is already unavaialble from Ruby level.

-- 
// SASADA Koichi at atdot dot net