From: KOSAKI Motohiro <kosaki.motohiro@...>
Date: 2012-10-02T03:29:15+09:00
Subject: [ruby-core:47794] Re: [ruby-trunk - Bug #7097][Assigned] Thread locals don't work inside Enumerator

On Mon, Oct 1, 2012 at 2:24 PM, KOSAKI Motohiro
<kosaki.motohiro@gmail.com> wrote:
> On Mon, Oct 1, 2012 at 2:12 PM, Aaron Patterson
> <tenderlove@ruby-lang.org> wrote:
>> On Tue, Oct 02, 2012 at 03:05:17AM +0900, kosaki (Motohiro KOSAKI) wrote:
>>>
>>> Issue #7097 has been updated by kosaki (Motohiro KOSAKI).
>>>
>>> Status changed from Open to Assigned
>>> Assignee set to ko1 (Koichi Sasada)
>>>
>>> I guess it's a side effect to use Fiber in Enumerator internal.
>>
>> Yes, it is.  I don't know why Fibers impact thread locals, but I hope
>> this test demonstrates how it can cause problems.
>
> Thread local variable is pretty misleading name. In fact, ruby only have
> a fiber local variable. i.e. Thread.current[:foo] is to write fiber
> local variable.
>
> Using 'Thread' class is a just historical reason, IMHO. (and I completely agree
> it's pretty misleading)

see also:

http://bugs.ruby-lang.org/issues/1717
http://bugs.ruby-lang.org/issues/5750