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Date: Mon, 24 May 2021 17:22:08 +0000
From: Eric Wong <e@80x24.org>
To: Ngan Pham <nganpham@gmail.com>
Cc: kgio-public@yhbt.net
Subject: Re: Patch for GC.compact memory issue
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Ngan Pham <nganpham@gmail.com> wrote:
> Hello, I'd like to submit a patch to fix an issue after running
> `GC.compact`. The LOCALHOST variable is defined in Ruby and is
> resolved and memoized (to `localhost`) in C once. However, the pointer
> in C is not GC marked. Running `GC.compact` potentially moves the
> `LOCALHOST` object in Ruby causing `localhost` to point to a bad or
> empty slot. This causes `env['REMOTE_ADDR']` to  a bad object in
> Unicorn.

Seems to make sense.

> Some useful links:
> - `GC.compact` introduced: https://bugs.ruby-lang.org/issues/15626.
> - My conversation with tenderlove over twitter on this issue:
> https://twitter.com/tenderlove/status/1396625048861954049

Can you please copy+paste the conversation here?
Accessibility-challenged users such as myself cannot
read it without JavaScript.  Thanks.