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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Unbounded strings (Was: Java vs Ada 95 (Was Re: Once again,
 Ada absent from DoD SBIR solicitation))
Date: 1996/11/27
Message-ID: <dewar.849074870@merv>#1/1
X-Deja-AN: 201016928
references: <325BC3B3.41C6@hso.link.com>
 <heatwole-ya023180002511960851580001@news.his.com> <E1FnJC.HI4@world.std.com>
 <heatwole-ya023180002611960850350001@news.his.com> <E1I0KG.M4r@world.std.com>
organization: New York University
newsgroups: comp.lang.ada
Date: 1996-11-27T00:00:00+00:00
List-Id: <comp.lang.ada>


Kevin D. Heatwole <heatwole@his.com> wrote:
>I suspect that even this approach would have some difficulties involving
>pool-specific (or global) locks.  While task A may allocate the storage
>out of its per-task pool of memory, task B may be the task that deallocates
>the memory later.  If you have two threads mucking about with the same
>pool of memory, you will need to implement some form of serialization.


That suspicion is wrong, there is for instance the familiar free storage
management technique (used in Microsoft Pascal, and in the x86 Alsys
implementation -- I know about the latter, I write it :-) where free simply
sets the free bit and NOTHING else, and recombination of blocks is done
entirely by the allocator. There are other techniques to avoid locking
for the free case.