Monitor + killing thread => thread in an aborting state

Hi
I am using ruby 1.8.6 (2007-09-24 patchlevel 111) [i386-mswin32].
I have made a small program, to see whether killing thread is safe, when
it is using a monitor.
I have 3 threads:
-writer, which changes global resource guarded by monitor
-interrupter, which kills and spawns writer in a loop
-main, which only monitors other threads

After a few seconds my program hangs, because kill method does not
return. Main thread says that the writer thread is in an aborting state.

Sample output:
writer: ok?
main: tick writer-#<Thread:0x3b4b1e run> interrupter-#<Thread:0x1a80aea
run>
interrupter: kill
interrupter: join
interrupter: sleep 1
interrupter: new
interrupter: sleep 2
writer: ok?
interrupter: kill
main: tick writer-#<Thread:0x1b66b06 aborting>
interrupter-#<Thread:0x1a80aea run>
main: tick writer-#<Thread:0x1b66b06 aborting>
interrupter-#<Thread:0x1a80aea run>
main: tick writer-#<Thread:0x1b66b06 aborting>
interrupter-#<Thread:0x1a80aea run>
(repeats infinitely)

Is it ruby’s bug?
See attachment for full program source.

Regards,
Christopher

For one thing you should use ruby 1.9 which uses the OS thread instead
of
native ruby threading. The other is when you kill or cancel thread you
need
to provide safe areas for your condemned thread to die so resources are
releases if any used.
Look into pthread about canceling.

On Sun, Feb 22, 2009 at 11:34 AM, Christopher Debski <