From: Olivier Dion via "Developers list for Guile, the GNU extensibility library" <guile-devel@gnu.org>
To: Damien Mattei <damien.mattei@gmail.com>,
guile-user <guile-user@gnu.org>,
guile-devel <guile-devel@gnu.org>
Subject: Re: map-par slower than map
Date: Thu, 13 Oct 2022 08:41:25 -0400 [thread overview]
Message-ID: <87zgdz6glm.fsf@laura> (raw)
In-Reply-To: <CADEOadcnDfLsFFeMayisQsWw3AuvKb+P1GBmgHGUmSHNQ08U9g@mail.gmail.com>
On Thu, 13 Oct 2022, Damien Mattei <damien.mattei@gmail.com> wrote:
> the code did not worked when data length were more little than number of
> cpus (6 on my host) (iota 5) returns #unsepcified:
Yeah sorry I miss indended the output and the rest. Here's a version
that should work:
--8<---------------cut here---------------start------------->8---
(use-modules
(srfi srfi-1)
(ice-9 threads))
(define* (par-map-vector proc input
#:optional
(max-thread (current-processor-count)))
(let* ((block-size (quotient (vector-length input) max-thread))
(rest (remainder (vector-length input) max-thread))
(output (make-vector (vector-length input) #f)))
(when (not (zero? block-size))
(let ((mtx (make-mutex))
(cnd (make-condition-variable))
(n 0))
(fold
(lambda (scale output)
(begin-thread
(let lp ((i 0))
(when (< i block-size)
(let ((i (+ i (* scale block-size))))
(vector-set! output i (proc (vector-ref input i))))
(lp (1+ i))))
(with-mutex mtx
(set! n (1+ n))
(signal-condition-variable cnd)))
output)
output
(iota max-thread))
(with-mutex mtx
(while (not (< n max-thread))
(wait-condition-variable cnd mtx)))))
(let ((base (- (vector-length input) rest)))
(let lp ((i 0))
(when (< i rest)
(let ((i (+ i base)))
(vector-set! output i (proc (vector-ref input i))))
(lp (1+ i)))))
output))
--8<---------------cut here---------------end--------------->8---
--
Olivier Dion
oldiob.dev
next prev parent reply other threads:[~2022-10-13 12:41 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-12 17:19 map-par slower than map Damien Mattei
2022-10-12 18:45 ` Maxime Devos
2022-10-12 20:20 ` Damien Mattei
2022-10-12 20:27 ` Damien Mattei
2022-10-12 21:29 ` Zelphir Kaltstahl
2022-10-14 8:21 ` Damien Mattei
2022-10-14 8:38 ` Zelphir Kaltstahl
2022-10-17 13:17 ` Damien Mattei
2022-10-22 16:01 ` Damien Mattei
2022-10-23 1:06 ` Damien Mattei
2022-10-23 23:18 ` Zelphir Kaltstahl
2022-10-24 3:56 ` Keith Wright
2022-10-24 7:03 ` Zelphir Kaltstahl
2022-10-24 4:39 ` Damien Mattei
2022-10-25 9:07 ` Mikael Djurfeldt
2022-10-25 9:11 ` Mikael Djurfeldt
2022-10-25 14:09 ` Damien Mattei
2022-11-10 10:32 ` Damien Mattei
2022-11-10 10:41 ` Damien Mattei
2022-11-10 10:52 ` Zelphir Kaltstahl
2022-11-10 13:36 ` Damien Mattei
2022-11-10 17:07 ` Olivier Dion via General Guile related discussions
2022-11-11 10:26 ` Damien Mattei
2022-11-11 12:25 ` Zelphir Kaltstahl
2022-11-11 13:36 ` Damien Mattei
2022-11-11 13:37 ` Damien Mattei
2022-11-13 8:23 ` Damien Mattei
2022-10-12 21:44 ` Maxime Devos
2022-10-12 21:55 ` Olivier Dion via Developers list for Guile, the GNU extensibility library
2022-10-13 7:40 ` Damien Mattei
2022-10-13 8:20 ` Damien Mattei
2022-10-13 9:10 ` Olivier Dion via Developers list for Guile, the GNU extensibility library
2022-10-13 10:44 ` Damien Mattei
2022-10-13 11:00 ` Olivier Dion via Developers list for Guile, the GNU extensibility library
[not found] ` <CADEOadfovi8s3OxRcssWOuOW8jjHoL9Z7pD_5FstSm=ZkBHP8g@mail.gmail.com>
2022-10-13 11:57 ` Fwd: " Damien Mattei
2022-10-13 12:36 ` Damien Mattei
2022-10-13 12:41 ` Olivier Dion via Developers list for Guile, the GNU extensibility library [this message]
2022-10-13 13:43 ` Damien Mattei
2022-10-13 14:06 ` Olivier Dion via Developers list for Guile, the GNU extensibility library
2022-10-13 14:10 ` Damien Mattei
2022-10-13 14:21 ` Damien Mattei
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