From: ygrek <ygrekheretix@gmail.com>
To: caml-list@yquem.inria.fr
Subject: threads
Date: Tue, 8 Sep 2009 20:33:19 +0300 [thread overview]
Message-ID: <20090908203319.cf4b1ff6.ygrekheretix@gmail.com> (raw)
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Hello,
let x = Array.make 100 []
let update i n = x.(i) <- n :: x.(i)
let read i = x.(i)
Consider the following scenario: one thread is `update`ing x, another
thread(s) uses only `read`. Is it safe to use these functions without
locking on mutex?
I.e. is Array.set atomic? What about updating references (:=) ?
If I understand correctly these operations require only one cpu
instruction to update one machine word and so should be atomic. Taking
into account "single-cpu affinity" of ocaml program it should be safe
to write such multithreaded code. Is it true?
Is it safe to assume that ocamlopt won't skip reads/writes to globally
visible memory address using cached value in a register?
--
ygrek
http://ygrek.org.ua
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next reply other threads:[~2009-09-08 17:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-08 17:33 ygrek [this message]
2009-09-08 23:20 ` [Caml-list] threads Philippe Wang
2009-09-10 18:17 ` ygrek
-- strict thread matches above, loose matches on Subject: below --
2005-06-10 17:56 Threads Jonathan Bryant
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