From: Ferenc Engard <engard@...>
Date: 2002-08-28T06:42:37+09:00
Subject: BUG: threads and ruby/tk

Hi there,

Here is the code:
--------------------------------
#!/usr/bin/ruby

require "tk"
$count=TkVariable.new "start"
l=TkLabel.new {
    pack
}
l.textvariable $count

TkButton.new {
    text "Test"
    command proc {puts "a"}
    pack
}
t=Thread.new {
    loop {
        $count.value="blah"
#        10000.times {1}
    }
}
Tk.mainloop
--------------------------------

This program executed with ruby 1.6.7 (2002-03-19) [i386-linux] on a P75
segfaults randomly when I push the "Test" button. If I uncomment the
delay loop, then not segfaults, only if I (with great timing) push the
button exactly when the $count.value=() method is executed.

Sample output:
--------------------------------
fery@domesticus:~$ ./test2.rb
a
a
a
/usr/lib/ruby/1.6/tk.rb:880: [BUG] Segmentation fault
ruby 1.6.7 (2002-03-19) [i386-linux]
Aborted
--------------------------------

The same program on ruby 1.6.6 (2001-12-26) [i586-mswin32] on winXP
(Athlon 1G) develops different symptom: if I try to move the Tk window,
the program freezes. The bug is present also if the t thread contains
only an empty loop. The segfault on buttonpress is not detected.

Bye:
Circum