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From: Haojun Bao <baohaojun AT gmail DOT com>
To: cygwin AT cygwin DOT com
Subject: Emacs can't start-process more than 30~40 processes (Was: Re: Emacs w3m `w3m-toggle-inline-images' cause segfault)
References: <83iqhlbgoc DOT fsf AT gmail DOT com> <4A6727A8 DOT 2090905 AT cornell DOT edu> 	<83iqhkur2h DOT fsf AT gmail DOT com>
Date: Mon, 27 Jul 2009 10:14:19 +0800
In-Reply-To: <83iqhkur2h.fsf@gmail.com> (Haojun Bao's message of "Thu, 23 Jul 	2009 09:27:18 +0800")
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I have reduced the test case in this mail 
  http://cygwin.com/ml/cygwin/2009-07/msg00111.html
to a simpler one:

    $/bin/emacs --batch -q  --execute '(let ((num 0))
      (while (< num 30)
        (setq num (+ num 1))
        (message "num is %d" num)
        (start-process "hello" nil "/usr/bin/echo")))'
    
Emacs will coredump at the 30th process it tries to start on my XP.

Now I think this should seem familiar to the experts. I tried to gdb it,
the backtrace shows segfault is happening at the same place 
(#0 0x610949d8 in fhandler_pipe::create () from /usr/bin/cygwin1.dll)

You might need to tweak the (< num 30) to (< num 40) or bigger, also, to
use gdb on it, you need write the lisp into a file and use `-l' to load
the file:

cat > ~/2.el <<End
(let ((num 0))
  (while (< num 40)
    (setq num (+ num 1))
    (message "num is %d" num)
    (start-process "hello" nil "/usr/bin/echo")))
End

gdb --args ./emacs --batch -q  -l ~/2.el


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