[Openmcl-devel] binding with threads

[David L. Rager]

FYI, here's my multi-threading interface, which works well on CCL and
should work on SBCL and LispWorks (but I test these lisps less often).

http://www.cs.utexas.edu/users/moore/acl2/current/distrib/acl2-sources/multi-threading-raw.lisp

And here's my futures implementation.  I originally omitted it because
it has some features you won't need (catching and rethrowing a given
set of tags), and it's missing something that Sedach's does provide
(error catching and rethrowing... iirc):

http://www.cs.utexas.edu/users/moore/acl2/current/distrib/acl2-sources/futures-raw.lisp

On Thu, Mar 21, 2013 at 11:38 AM, Vijay Mathew
<vijay.the.lisper at gmail.com> wrote:
> Hi David,
>
> Thanks for your reply.
> I wrote the futures library just as an exercise for learning Common Lisp.
> You can download it here: http://ubuntuone.com/4XEnbbdvhccGOqC6WqGJ3S. BTW,
> I am still debugging it!
>
> I am on CCL 1.10 dev trunk.
>
> Thanks,
>
> --Vijay
>
>
> On Thu, Mar 21, 2013 at 7:57 PM, David L. Rager <ragerdl at gmail.com> wrote:
>>
>> Hi Vijay,
>>
>> Welcome to the world of CCL threads!
>>
>> I don't yet know the answer to your first question.  However, maybe
>> you can figure it out with this debugging hint:  I have my own
>> multi-threading package, so this will look like pseudo-code.  The most
>> common thing I do is interrupt a thread and view its backtrace, which
>> should help you in this instance.
>>
>> (all-threads)  ; or :proc, or (ccl:all-processes) iirc
>> (interrupt-thread (nth <n> (all-threads)) #'break)
>> :y <thread-number-to-yield-to>
>> :b ; for backtrace
>> <other common debugging features>
>>
>> Is your futures library available?  There are various Lisp libraries
>> that provide parallel execution.  For example, Vladamir Sedach
>> provides an eager futures library [
>> http://common-lisp.net/project/eager-future/ ].  Also, I provide a
>> "plet" primitive (and others, like "spec-mv-let") for ACL2, which is
>> built on top of CL [
>> http://www.cs.utexas.edu/users/moore/acl2/current/PLET.html ].  If
>> you'd like more information about the latter, feel free to inquire
>> (probably off the list-serve).
>>
>> David
>>
>> PS -- setf can be different than just using let.  Maybe using or not
>> using special variables is part of the issue?
>> PPS -- are you on CCL 1.9 or later?  There was a bug for a little bit
>> right before the 1.9 release, but I'd be surprised if you were hitting
>> it in this simple test case.
>>
>>
>> On Thu, Mar 21, 2013 at 5:41 AM, Vijay Mathew
>> <vijay.the.lisper at gmail.com> wrote:
>> > Consider this code snippet which demonstrates a "futures" package for
>> > executing computations asynchronously:
>> >
>> > (setf e (futures:make-pool-executor 2))
>> > (setf f1 (futures:executor-submit e #'(lambda (x) (* x 2)) 100))
>> > (setf f2 (futures:executor-submit e #'(lambda (x y) (+ x y)) 200 300))
>> > (format t "~A~%" (futures:future-result f1))
>> > (format t "~A~%" (futures:future-result f2))
>> > (futures:executor-shutdown e nil)
>> >
>> > `pool-executor' internally uses a pool of ccl threads for executing the
>> > jobs
>> > submitted to it. Now if I rewrite the same sample using `let' bindings,
>> > the
>> > call to `future-result' just hangs. The threads actually run, but it
>> > seems
>> > `future-result' somehow do not see the updated value of the internal
>> > `result' slot.
>> >
>> > If I load this script, it just hangs the CCL REPL:
>> >
>> > (let ((e (futures:make-pool-executor 2)))
>> >   (let ((f1 (futures:executor-submit e #'(lambda (x) (* x 2)) 100))
>> >         (f2 (futures:executor-submit e #'(lambda (x y) (+ x y)) 200
>> > 300)))
>> >     (format t "~A~%" (futures:future-result f1))
>> >     (format t "~A~%" (futures:future-result f2))
>> >     (futures:executor-shutdown e nil)))
>> >
>> > Also I would like to learn about the best way to debug programs that use
>> > CCL
>> > threads.
>> >
>> > I am new to Common Lisp and the kind of support I am getting from this
>> > mailing list is very encouraging!
>> >
>> > Thank you,
>> >
>> > --Vijay
>> >
>> >
>> > _______________________________________________
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>> > Openmcl-devel at clozure.com
>> > http://clozure.com/mailman/listinfo/openmcl-devel
>> >
>
>