From: Laurent Sansonetti <pinux@...>
Date: 2003-10-07T23:05:36+09:00
Subject: FreeBSD problem with processes

Hi all,

I noticed a weird problem when starting processes after loading both
Ruby/GTK2 and PTY extensions:

$ cat crash.rb
require 'gtk2'
require 'pty'
`test`

$ ruby crash.rb
Fatal error 'Unable to read from thread kernel pipe' at line 1100 in
file /usr/src/lib/libc_r/uthread/uthread_kern.c (errno = 0)
Abort trap (core dumped)

It does not crash if I comment any 'require' line.

$ uname -a
FreeBSD natalie 5.1-RELEASE FreeBSD 5.1-RELEASE #1: Sat Sep  6 13:12:23
GMT 2003     root@natalie:/usr/src/sys/i386/compile/NATALIE  i386

$ ruby -v
ruby 1.8.0 (2003-08-04) [i386-freebsd5]

Here is GDB's bt:

(gdb) bt
#0  0x281ac3e3 in kill () from /usr/lib/libc.so.5
#1  0x282171ec in abort () from /usr/lib/libc.so.5
#2  0x284b7145 in _thread_exit () from /usr/lib/libc_r.so.5
#3  0x284b4f55 in _thread_kern_sig_undefer () from /usr/lib/libc_r.so.5
#4  0x284b4694 in _thread_kern_sched_state_unlock () from
/usr/lib/libc_r.so.5
#5  0x284b4050 in _thread_kern_scheduler () from /usr/lib/libc_r.so.5

--

I'm really confused about this problem.  I know it's related to
FreeBSD's libc_r library, but I don't know how to investigate further.

Any advice on how to debug and fix this?

Thanks in advance,

-- 
{ "Laurent" => "http://lrz.samika.net" }