[Fwd: RE: Is JAMA thread-safe]

[Ron Boisvert <boisvert@nist.gov>]

Sender: "G. W. (Pete) Stewart" <stewart@cs.umd.edu>
Subject: RE: Is JAMA thread-safe



If Jama was not designed with thread safety in mind, it probably is
not.  But if the LAPACK experience is typical, it probably would not
be hard to make it so.  LAPACK has few routines that SAVE information
in static variables, which is thread dangerous.  It has no COMMON
statements, so it does not modify global variables, another dangerous
practice.  Since some vendors have offered thread-safe versions of
LAPACK, its fair to conclude there are work-arounds for the few
routines that have SAVE variables.

The reference implementation of the BLAS, which LAPACK uses, appears
to be thread safe.  But that is no guarantee that vendor implemented
BLAS are also thread safe.

I forget if Jama has random matrix generators, but those could be a
problem, since they must save a seed.  A web search gave conflicting
opinions on the thread safety of Java's random number generators.

Pete Stewart

On Mon, 9 Oct 2006, Cleve Moler wrote:

> Date: Mon, 9 Oct 2006 18:27:26 -0400 (EDT)
> From: Cleve Moler <moler@mathworks.com>
> Reply-To: jama@nist.gov
> To: Multiple recipients of list <jama@nist.gov>
> Subject: RE: Is JAMA thread-safe
>
> I certainly never considered that issue when I wrote much of the code a
> few years ago.  What does it take to make it thread safe?
>
>   -- Cleve Moler
>      The MathWorks
>
> -----Original Message-----
> From: jama@nist.gov [mailto:jama@nist.gov] On Behalf Of Geri Wagner
> Sent: Monday, October 09, 2006 10:27 AM
> To: Multiple recipients of list
> Subject: Is JAMA thread-safe
>
> Hi
>
> I wonder whether the JAMA implementation is thread-safe.
>
> I could not find a statetment on the website, but perhaps I have
> overlooked it. Thank you for comments.
>
> --
> ----------------------------------------
> Dr. Geri Wagner
> Quantitative Analyst
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> Swissrisk AG
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