Ooh good catch! I have such an issue in my thread-per-jar function, the variable f which is bound in the loop, closed over in the thread run function but executed in a thread! That could explain both the missing values and the duplicates one. I'll report back. 

Thanks!
Alan
-Alan

http://alan.ruttenbergs.com/


On Sat, Sep 28, 2013 at 11:44 AM, Pascal J. Bourguignon <pjb@informatimago.com> wrote:

Mark Evenson <evenson@panix.com> writes:

> On Sep 27, 2013, at 9:28 PM, Mark Evenson <evenson@panix.com> wrote:
>
>>
>> On Sep 27, 2013, at 8:13 PM, "Alan Ruttenberg" <alanruttenberg@gmail.com> wrote:
>>
>>> Agreed. While the gethash and puthash should independently work,
>>> the combination of the two isn't thread safe. For example two
>>> processes could get the value in the ht before either has a chance
>>> to write back the increment.
>>
>> A version that only adds to unique keys in the hash table, relying
>> on the HASH-TABLE-COUNT value to indicate successful update. The
>> keys are the squares of the first eight primes, so the total threads
>> spawned is eight. the parameter to RUN now indicates how many
>> squares of the given prime basis. But still weirdness, in that the
>> first thread which should increment the keys of the hashtable
>> indexed by the powers of 2 doesn't seem to execute. Something in my
>> LOOP clause?
>>
>> <threaded-hash.lisp>
>
> Indeed a faulty understanding of LOOP:
>
> CL-USER> (loop :for n :in '(2 3 5 7 11 13 15 17) :doing (threads:make-thread (lambda () (format t "~A " n))))
>
> 3 5 7 11 13 15 17
> 17 NIL
>
> The value of "n" has already been incremented past the first member of the list when the closure is created with LAMBDA, so the thread with "2" never gets executed.
>
> SLIME users: one needs to place the form (setf
> swank:*globally-redirect-io* t) in ~/.swank.lisp to get all the FORMAT
> output in the REPL buffer. Otherwise look in the corresponding
> *inferior-lisp* buffer.
>
> So, I guess one should loop over closures that have been correctly
> initialized with the right values in some other manner. I'd go for
> using DO over LOOP for unless someone can correct my understanding.
> Either that, or I need to follow macro expansions.

DO won't help better. For LOOP, DOTIMES, DOLIST, it's unspecified
whether the variables are new bindings or updated bindings. But for DO
and DO*, it is specified they're updated. So while with the former you
had a chance for it to work (not conformingly), you stand no such chance
with DO.

What you must write is:

(ql:quickload :bordeaux-threads)

(loop :for n :in '(2 3 5 7 11 13 15 17)
:do (let ((n n))
(bt:make-thread (lambda () (format t "~A " n)))))

(do ((ns '(2 3 5 7 11 13 15 17) (cdr ns)))
((null ns))
(let ((n (car ns)))
(bt:make-thread (lambda () (format t "~A " n)))))

--
__Pascal Bourguignon__
http://www.informatimago.com/