sbcl-help

[Sbcl-help] Oddity with make-thread and sleep.

[Sean R. <sd...@jh...>]

Hi all,

 I've come across a slight oddity when using sb-thread:make-thread
 and sleep. Running the following code on SBCL 0.8.7.55 and SBCL 0.8.20.28 
 on Linux x86 produces surprising results.
 
 
 (time (progn (sb-thread:make-thread #'(lambda () (print "Hello")))
              (sleep 5)))

 => 
  "Hello" 
  Evaluation took:
    0.001 seconds of real time
    0.0 seconds of user run time
    0.0 seconds of system run time
    0 page faults and
    0 bytes consed.
  NIL
 
 Running sleep on it's own does what is expected but when
 run in conjunction with make-thread it returns instantly.

 This seems to be caused by the call to select getting interrupted at 
 some point. Replacing sleep with 
 (multiple-value-list (sb-unix:unix-select 0 0 0 0 1 0))
 seems to bear this out, although where it happens though is beyond me.

  
 Regards, 
   Sean.

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Re: [Sbcl-help] Oddity with make-thread and sleep.

[<me...@ho...>]

On Tuesday 22 March 2005 14:51, Sean Ross wrote:
>  Running sleep on it's own does what is expected but when
>  run in conjunction with make-thread it returns instantly.
>
>  This seems to be caused by the call to select getting interrupted at
>  some point. Replacing sleep with
>  (multiple-value-list (sb-unix:unix-select 0 0 0 0 1 0))
>  seems to bear this out, although where it happens though is beyond me.

It is SIG_THREAD_EXIT signaled by the child on exit that interrupts the select 
call. A gc triggered in another thread also interrupts sleep and these system 
calls are not restarted automatically.

The attached patch implements sleep with nanosleep, calling it again when 
necessary.

Cheers, Gabor

>
>
>  Regards,
>    Sean.

Re: [Sbcl-help] Oddity with make-thread and sleep.

[Daniel B. <da...@te...>]

G=E1bor Melis <me...@ho...> writes:

> The attached patch implements sleep with nanosleep, calling it again when=
=20
> necessary.

Thanks.  Do you know how portable nanosleep() is?  The manual page
I have says POSIX.1b, so slightly-special but not especially-special.

SBCL committers: I propose to apply this patch, so if an OS you're
using has no nanosleep() or no working nanosleep, now would be a
really good time to object.  Cheers.


-dan

Re: [Sbcl-help] Oddity with make-thread and sleep.

[Raymond W. <Ray...@fa...>]

Daniel Barlow writes:
 > G=E1bor Melis <me...@ho...> writes:
 >=20
 > > The attached patch implements sleep with nanosleep, calling it aga=
in when=20
 > > necessary.
 >=20
 > Thanks.  Do you know how portable nanosleep() is?  The manual page
 > I have says POSIX.1b, so slightly-special but not especially-special=
.
 >=20
 > SBCL committers: I propose to apply this patch, so if an OS you're
 > using has no nanosleep() or no working nanosleep, now would be a
 > really good time to object.  Cheers.

        FreeBSD and Mac OS X 10.3.8 have nanosleep, and claims=20

:     The nanosleep() system call conforms to IEEE Std 1003.1b-1993
:     (``POSIX.1'').

--- any bets that the supposedly Posix-compatible MS Windows supports
this :-?

Re: [Sbcl-devel] Re: [Sbcl-help] Oddity with make-thread and sleep.

[Gabor M. <gab...@es...>]

On Monday 04 April 2005 18:18, Daniel Barlow wrote:
> G=E1bor Melis <me...@ho...> writes:
> > The attached patch implements sleep with nanosleep, calling it again
>
> when
>
> > necessary.
>
> Thanks.  Do you know how portable nanosleep() is?  The manual page
> I have says POSIX.1b, so slightly-special but not especially-special.
>
> SBCL committers: I propose to apply this patch, so if an OS you're
> using has no nanosleep() or no working nanosleep, now would be a
> really good time to object.  Cheers.
>
>
> -dan

Oops, I forgot to include tools-for-build in the patch.

Index: tools-for-build/ldso-stubs.lisp
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
RCS file: /cvsroot/sbcl/sbcl/tools-for-build/ldso-stubs.lisp,v
retrieving revision 1.5
diff -u -r1.5 ldso-stubs.lisp
=2D-- tools-for-build/ldso-stubs.lisp     6 Jan 2005 12:48:05 -0000       1=
=2E5
+++ tools-for-build/ldso-stubs.lisp     5 Apr 2005 13:48:51 -0000
@@ -198,6 +198,7 @@
                    "malloc"
                    "memmove"
                    "mkdir"
+                   "nanosleep"
                    "nl_langinfo"
                    "open"
                    "opendir"