[gambit-list] with-output-to-process hangs in OSX

Meng Zhang wsxiaoys.lh at gmail.com
Mon Nov 14 21:28:45 EST 2011


FYI,
call stack in 4.1
0 ##thread-check-interrupts! 
1 ##thread-sleep! 
2 ##process-status 
3 with-output-to-process 

-- 
Meng Zhang
Sent with Sparrow (http://www.sparrowmailapp.com/?sig)
On 2011年11月15日星期二 at 上午10:15, Meng Zhang wrote: 
> 
> 
> On Tue, Nov 15, 2011 at 10:04 AM, Marc Feeley <feeley at iro.umontreal.ca (mailto:feeley at iro.umontreal.ca)> wrote:
> > 
> >  On 2011-11-14, at 8:40 PM, Meng Zhang wrote:
> > 
> > > >> Below are code I wrote to reproduce the problem
> > > >>
> > > >> (with-output-to-process
> > > >>  (list path: "sed"
> > > >>  arguments: '("-e" "s/n/N/g"))
> > > >>  (lambda ()
> > > >>  (display "nothing")))
> > > >>
> > >
> > > Actually, I can't get your example to run without an error on v4.6.2 . Can I ask you what you expected your code to do?
> > > This problem happened in 4.6.1, not 4.6.2
> > 
> > I understand. But you said that once you upgraded to v4.6.2 the problem went away. But when I try with v4.6.2 I get the same result as v4.6.1 on the code above. So I am wondering why there is a difference on v4.6.2.
> > 
> > > It is sending the text "nothing" to sed's input. Are you expecting the output of sed to appear on the terminal?
> > >
> > > The procedure with-output-to-process gives to sed a *closed* file descriptor for its stdout. This is why sed complains ("sed: stdout: Broken pipe"). If you didn't want this, you can give an stdout-redirection: #f setting and sed's stdout will be the same as the interpreter's stdout (usually the terminal):
> > > In 4.6.1, when I run the code above, the current thread sleeps forever.(since the stack frame is at "thread-sleep!")
> > 
> > What happens when you try the code below?
> > 
> > > (with-output-to-process
> > > (list path: "sed"
> > > arguments: '("-e" "s/n/N/g")
> > > stdout-redirection: #f)
> > > (lambda ()
> > > (display "nothing\n")))
> > 
> > Do you get the output on the screen?
> Yes, it prints "NothiNg" and then fall asleep without exiting.(in 4.6.1)
> > 
> >  Marc
> > 
> 
> 
> 
> -- 
> Zhang Meng
> School of Software Engineering, Tongji University
> MP: +86 151-2103-2798

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