From: matz@... (Yukihiro Matsumoto)
Date: 2002-12-18T17:59:38+09:00
Subject: Re: Threads raising exceptions

Hi,

In message "Threads raising exceptions"
    on 02/12/18, Tim Bates <tim@bates.id.au> writes:

|I have the following piece of threading code:
|
|Thread.new(i) do |j|
|	#$SAFE = 4
|	b = 0
|	loop do
|		b += 1
|		raise 'Test' if j == 3 and b == 100
|		sleep(0)
|	end
|end
|
|This behaves as expected - if Thread.abort_on_exception is true, the program 
|throws an exception and dies, otherwise just this thread dies, and no  
|exception I can rescue. So far, so good.
|
|If, however, I uncomment the line with $SAFE = 4, it behaves as if 
|Thread.abort_on_exception is false, and so I can't catch any exception when a 
|thread dies, and so I can't find out what happened, which I need to! What can 
|I do about this?

use Thread#join or Thread#value to retrieve exception from the dead
thread.  It is so to avoid process termination by exceptions from
untrusted code.  For debugging, $DEBUG=true will print exception names.

							matz.