From: matz@... (Yukihiro Matsumoto)
Date: 2004-01-24T16:59:39+09:00
Subject: Re: Problem with Exceptions and Threads

Hi,

In message "Problem with Exceptions and Threads"
    on 04/01/24, Pit Capitain <pit@capitain.de> writes:

|recently I had a problem writing unit tests using timeout.rb and other 
|threads. The smallest reproducible testcase I came up with is this:

When the main thread terminates, the other threads are terminated
automagically.  Thus

|# test_own_error_in_thread => works

This works by accident.  The execution of the threads reaches end
before context switch.  Thus adding "join" at the end of Thread#new
would help:

|begin
|   main = Thread.current
|   Thread.new do
|     begin
|       Thread.new do end # this line makes the difference
|       raise TestError, "error3"
|     rescue Exception
|       main.raise $!
|     end
|   end.join    # <-- note ".join" here
|rescue TestError
|   puts $! # doesn't print "error3"
|end

							matz.