[slime-devel] Re: single-threaded swank backend and message loops
nikodemus at random-state.net
Mon Nov 6 10:31:54 UTC 2006
"Jack Unrue" <jdunrue at gmail.com> writes:
> When I run sbcl via slime, not only does the slime repl freeze
> (which I accept as expected behavior), but the blocking call to
> get-message never returns either. I can use C-c C-c to interrupt
> sbcl, though.
The first order of business is to see if the happens without Slime. If
yes, we should probably take this to sbcl-devel...
Even if Slime is a required component, this does sound like an SBCL
> With some experimental hackery, which I have not yet boiled down to
> a workable solution, I can actually get a functional message loop
> running in the slime/sbcl case. This involves bastardizing my code's
> setup for the loop one time, let that execute and so it immediately
> returns control to slime, and then restore the correct code. So
> there seems to be a possibility of achieving the same behavior as
> I'm getting with clisp.
I'm not sure I understand. On one hand you say that your loop hangs in
GetMessage, which never returns, on the other you say that sometimes
it doesn't hang?
Can you send a test-case & example? (Depending on eg. GRAPHIC-FORMS is
OK, though a self-contained test-case would be nicer.)
A couple of not-directly applicable, but still related, things:
* On Windows SBCL currently converts between FDs and HANDLEs in a way
that is liable to cause trouble sooner or later. I would not be
overly surprised if you troubles are mysteriously related to this. I
have an slightly mutant (and right now defunct) tree that uses
HANDLEs only, but there is still more work to be done there before
it is good to go.
* In the long run SBCL will likely provide a wrapper on
MsgWaitForMultipleObjects, so you can structure your loop something
(loop (process-message (sb-windows:get-message :serve-events t)))
where SB-WINDOWS:GET-MESSAGE also deals with IO events from eg.
Slime, dispatching them to the appropriate handlers. Since things
like GRAPHIC-FORMS are probably among the primary users of such
interfaces, your input on this would be good to have.
-- Nikodemus Schemer: "Buddha is small, clean, and serious."
Lispnik: "Buddha is big, has hairy armpits, and laughs."
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