From: Ryan Davis <ryand-ruby@...>
Date: 2008-07-31T12:39:18+09:00
Subject: Re: gc doesn't collect?


On Jul 30, 2008, at 17:40 , Eric Hodel wrote:

> On Jul 30, 2008, at 17:13 PM, Roger Pack wrote:
>> Any ideas why:
>>
>> 1.times { a = 'a'*1000};
>> 30.times { GC.start };
>> print ObjectSpace.each_object{|o| print o}
>>
>> prints out 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...' despite the fact  
>> that
>> the a's should have been collected?
>
> Ruby's garbage collector walks the C stack looking for values that  
> appear to point to the ruby heap.  Ruby thinks you still have a  
> reference to your string because of this.

well... I think in this case it is because he never dereferenced a, so  
it is still a valid live object. {} doesn't scope variables the same  
way as in, say, C.