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From: Victor Porton <porton@narod.ru>
Subject: Re: Deallocating an object twice
Date: Sun, 27 Jul 2014 18:34:03 +0300
Date: 2014-07-27T18:34:03+03:00	[thread overview]
Message-ID: <lr3658$e1g$1@speranza.aioe.org> (raw)
In-Reply-To: 85bnsarfad.fsf@stephe-leake.org

Stephen Leake wrote:

> Victor Porton <porton@narod.ru> writes:
> 
>> If I understand correctly, it is an undefined behavior (or is it called
>> unbounded error?) if a pool access is deallocated twice with
>> Unchecked_Deallocation.
> 
> You misunderstand.
> 
> ARM 2012 13.11.3
> 
> Procedure Free has the following effect:
> 
> 7
>      1.  After executing Free(X), the value of X is null.
> 
> 8
>      2.  Free(X), when X is already equal to null, has no effect.

No, it is that you misunderstand me:

Second free may be executed not as Free(X) but as Free(Y) where Y was a copy 
of X (and so Free(X) sets only X to null, it does not set Y to null; and 
Free(Y) would be erroneous).

-- 
Victor Porton - http://portonvictor.org


  reply	other threads:[~2014-07-27 15:34 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-26 19:55 Deallocating an object twice Victor Porton
2014-07-26 20:02 ` Victor Porton
2014-07-27  2:39   ` Randy Brukardt
2014-07-27  2:42   ` Randy Brukardt
2014-07-27  8:31 ` Simon Wright
2014-07-27 11:30 ` anon
2014-07-27 12:47   ` Peter Chapin
2014-07-27 15:29 ` Stephen Leake
2014-07-27 15:34   ` Victor Porton [this message]
2014-07-28 15:15     ` Stephen Leake
2014-07-28 16:15       ` Simon Wright
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