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<p>Hello John.<br>
</p>
<br>
<div class="moz-cite-prefix">On 10/07/2016 06:54 PM, John Paulson
wrote:<br>
</div>
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cite="mid:CAGZnXMjBGG5oueoVNAwW9ESgKV6jP-AF0ODb5owGQhuGV=zo9g@mail.gmail.com"
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<div dir="ltr">Hi Enea and Roberto,
<div><br>
</div>
<div>Thank you very much for all of the work you have done on
threading with PPL. I have a couple of questions about the
current status of the thread safety. A project I am currently
working on needs to have multiple threads working
simultaneously on distinct PPL objects. Is that possible with
the new thread safe version?</div>
</div>
</blockquote>
<br>
Yes, it is possible.<br>
<br>
If the PPL objects are distinct, so that there is no concurrent
access to the *same* object, then things should not be difficult
(e.g., no need at all for synchronization). You can have a look to
the ppl_lcdd and ppl_lpsol demos or to the recently added tests in
tests/Polyhedron/threadsafe*.cc<br>
<br>
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<div dir="ltr">
<div><br>
</div>
<div>I made an implementation of my current project where I fork
processes instead of using multiple threads. However, if I
fork and have two processes manipulating distinct PPL objects,
I do not get a speedup by a factor of two like I would expect.
Is there anyway to get that type of speedup?</div>
</div>
</blockquote>
<br>
If you use many process, then the PPL should be working fine "as is"
(i.e., with thread-safety off).<br>
As for the missing speedup, I doubt it has something to do with the
library:<br>
there should be something else going on, but I have no information
to guess what it could be.<br>
<br>
Cheers,<br>
Enea.<br>
<br>
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<div dir="ltr">
<div><br>
</div>
<div><br>
</div>
<div>Best,</div>
<div>John C. Paulson</div>
</div>
<br>
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