From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8BE3F258CD9; Thu, 24 Jul 2025 00:00:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753315214; cv=none; b=BrVSM14sV1BJqdmDvLrskcLQ1y9MEZaTyA9vlqbiAdiT5akF+jwtgtc1QczIfomqxAFmERsaA+W08+6AbYOitEWz4tyZkCeHSP5BhGLpZviDRe0OwddhLDWiqJkyAVmPo58RLROEtlUHrEPAQFjsFDtmaxtKnA7fJq7nrrQY160= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753315214; c=relaxed/simple; bh=AKAbS84gY9dQXK7Kck1l0OWH2nxfXnqOEWKnlLaSrLk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=H/eNIx4XpjuY9Gn3Wzp4cEkhk+NrblH58BkFzv8kgHwiM4HBGi2t2XeQPVWKwsVGFVFVFVYOZZnJXptbZP6B5puivtWs43LhLZ20XBqzkLd9oJ/ClYixlmSe8seWpZj9lEV51Wqk38POUsMY0Okuq0XY5/oNSrHrHdgyRFiJ5No= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jlAdODo2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jlAdODo2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26FB1C4CEF4; Thu, 24 Jul 2025 00:00:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753315214; bh=AKAbS84gY9dQXK7Kck1l0OWH2nxfXnqOEWKnlLaSrLk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jlAdODo2cRl2kGQJlIOYP4S0jZ/R3cWNEkedJmZJKtZTe41eaNspg0ogTmwlyT9R2 xjXYpaXltPfGUCwck3jh9SOErGAygFr2xXAEnHbYPG/5+0nIdBx9ENS6poztjR7If9 RL3HCKt6rI8SrRPrmLpCxmfCfJukYCagvlfc5UAdrsNWPRh+ZjYuZfvezT4iukEDj7 qnIY/T7BEvm9z7J5oDokIToTWnaXMUYjFtp1ZUQ4cv0RgmDB5Dt8E+8NztbVaPXiCU SaZFCpPQkaEVsCL5VjNW8bfRSdptLgmd320ejwi4fItm66iw4HmjtXvn5bcQpdbujF FWK/hAuZA7nCw== From: Gary Guo To: Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?UTF-8?q?Bj=C3=B6rn=20Roy=20Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Tamir Duberstein , Alexandre Courbot , Alex Mantel Cc: Will Deacon , Peter Zijlstra , Mark Rutland , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 2/5] rust: make `Arc::into_unique_or_drop` associated function Date: Thu, 24 Jul 2025 00:32:55 +0100 Message-ID: <20250723233312.3304339-3-gary@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250723233312.3304339-1-gary@kernel.org> References: <20250723233312.3304339-1-gary@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Gary Guo Make `Arc::into_unique_or_drop` to become a mere associated function instead of a method (i.e. removing the `self` receiver). It's a general convention for Rust smart pointers to avoid having methods defined on them, because if the pointee type has a method of the same name, then it is shadowed. This is normally for avoiding semver breakage, which isn't an issue for kernel codebase, but it's still generally a good practice to follow this rule, so that `ptr.foo()` would always be calling a method on the pointee type. Reviewed-by: Benno Lossin Signed-off-by: Gary Guo --- rust/kernel/sync/arc.rs | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs index 63a66761d0c7d..4ee155b43b2dc 100644 --- a/rust/kernel/sync/arc.rs +++ b/rust/kernel/sync/arc.rs @@ -321,7 +321,7 @@ pub fn ptr_eq(this: &Self, other: &Self) -> bool { /// use kernel::sync::{Arc, UniqueArc}; /// /// let arc = Arc::new(42, GFP_KERNEL)?; - /// let unique_arc = arc.into_unique_or_drop(); + /// let unique_arc = Arc::into_unique_or_drop(arc); /// /// // The above conversion should succeed since refcount of `arc` is 1. /// assert!(unique_arc.is_some()); @@ -337,18 +337,18 @@ pub fn ptr_eq(this: &Self, other: &Self) -> bool { /// let arc = Arc::new(42, GFP_KERNEL)?; /// let another = arc.clone(); /// - /// let unique_arc = arc.into_unique_or_drop(); + /// let unique_arc = Arc::into_unique_or_drop(arc); /// /// // The above conversion should fail since refcount of `arc` is >1. /// assert!(unique_arc.is_none()); /// /// # Ok::<(), Error>(()) /// ``` - pub fn into_unique_or_drop(self) -> Option>> { + pub fn into_unique_or_drop(this: Self) -> Option>> { // We will manually manage the refcount in this method, so we disable the destructor. - let me = ManuallyDrop::new(self); + let this = ManuallyDrop::new(this); // SAFETY: We own a refcount, so the pointer is still valid. - let refcount = unsafe { me.ptr.as_ref() }.refcount.get(); + let refcount = unsafe { this.ptr.as_ref() }.refcount.get(); // If the refcount reaches a non-zero value, then we have destroyed this `Arc` and will // return without further touching the `Arc`. If the refcount reaches zero, then there are @@ -365,7 +365,7 @@ pub fn into_unique_or_drop(self) -> Option>> { // must pin the `UniqueArc` because the values was previously in an `Arc`, and they pin // their values. Some(Pin::from(UniqueArc { - inner: ManuallyDrop::into_inner(me), + inner: ManuallyDrop::into_inner(this), })) } else { None -- 2.49.0