> Date: Sat, 28 Jan 2023 02:36:03 +0000
> From: Glenn Takanishi <gl...@neuralmachines.com>
>
> I using Mit-scheme 12.1 trying to use the program "thread.scm" in the
> runtime directory. This program has the procedure "make-thread" in it.
> But when I tried to run a test with the following program below, it
> failed with the error message "Unbound variable: make-thread".
>
> [...]
> ;; (load "/usr/local/mit-scheme/lib/mit-scheme/runtime/thread.scm")
> [...]
>
> I wondering why this threads extension is not documented as the
> thread.scm program looks good. I'd like to see how this runs.
>
> Can you tell me what I need to add to the test code above to get it to
> run.
This file, thread.scm, is not an extension -- it's a built-in part of
MIT Scheme. The make-thread procedure in it is purely internal, not
for use of the API.
To start a thread, use create-thread, like this:
(create-thread #f
(lambda ()
(sleep-current-thread 1000)
(write-line 'hello-world)))
Longer example with a mutex and condition variable:
(define m (make-thread-mutex))
(define c (make-condition-variable))
(define done? #f)
(define t
(create-thread #f
(lambda ()
(sleep-current-thread 1000)
(with-thread-mutex-lock m
(lambda ()
(set! done? #t)
(condition-variable-broadcast! c))))))
(with-thread-mutex-lock m
(lambda ()
(do () (done?)
(condition-variable-wait! c m))))
FYI: The threads do not actually run in parallel at the moment. They
are time-shared. So they are useful for doing I/O asynchronously, but
not for parallelizing computation. (This might change some day.)
