From: Eric Wong <normalperson@...>
Date: 2013-08-24T19:06:15+00:00
Subject: [ruby-core:56800] Re: [ruby-trunk - Bug #8816][Third Party's Issue] Tempfile.new may return the same name for parallel calls

"akr (Akira Tanaka)" <akr@fsij.org> wrote:
> http://bogomips.org/kgio.git/tree/test/test_unix_connect.rb :
> 
>   class TestKgioUnixConnect < Test::Unit::TestCase
> 
>     def setup
>       tmp = Tempfile.new('kgio_unix')
>       @path = tmp.path
>       File.unlink(@path)
>       tmp.close rescue nil
>       @srv = Kgio::UNIXServer.new(@path)
>       @addr = Socket.pack_sockaddr_un(@path)
>     end
> 
> The race condition should be solved by application.

Agreed (kgio maintainer here).

Hleb: can you send me a patch to retry on bind failure?

I'm a little surprised it happens since $$ is in the Tempfile name and
the tests are not multi-threaded (but optionally multi-process).

> Because another process may creates the file between unlink and unix
> socket creation.
> Tempfile cannot do anything between them because Tempfile methods are
> not running at that time.

Right.  I do this often in test cases, but I'm lazy and have never hit
a problem even though I know it's there :x