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Date:   Sat, 31 Dec 2022 19:47:32 +0000
From:   Gary Guo <gary@garyguo.net>
To:     Wedson Almeida Filho <wedsonaf@gmail.com>
Cc:     rust-for-linux@vger.kernel.org, Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        =?UTF-8?B?QmrDtnJu?= Roy Baron <bjorn3_gh@protonmail.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 6/7] rust: sync: introduce `UniqueArc`
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On Wed, 28 Dec 2022 06:03:45 +0000
Wedson Almeida Filho <wedsonaf@gmail.com> wrote:

> Since `Arc<T>` does not allow mutating `T` directly (i.e., without inner
> mutability), it is currently not possible to do some initialisation of
> `T` post construction but before being shared.
> 
> `UniqueArc<T>` addresses this problem essentially being an `Arc<T>` that
> has a refcount of 1 and is therefore writable. Once initialisation is
> completed, it can be transitioned (without failure paths) into an
> `Arc<T>`.
> 
> Suggested-by: Gary Guo <gary@garyguo.net>
> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/kernel/sync.rs     |   2 +-
>  rust/kernel/sync/arc.rs | 152 +++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 151 insertions(+), 3 deletions(-)