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 87C98BA34; Sun, 22 Jun 2025 12:58:56 +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=1750597136; cv=none; b=c1MxA2fyIPY/6d/vajfzupoyi30dieOI7AgJ1G1Kt21eNLA+J5gr1QOwFBaLLawmHtan6bhdKFkrVLS0gHl5PbDlC4XG9eSaUTt/p2y8C8Pt5oNwki2eiSodwF6SoE9PYiSvyQr5qbv6XAode5hTksVaaUoak38MQkBmJqh4uJ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750597136; c=relaxed/simple; bh=Ygh4EXiwp2YXoTEH7jX4nu7C8/6De8xwJ1XjogF3BR0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ij5g5XrWWtpRtyanI/eYGYvX6nCg1RBCxPWoZgbW7vK5zcax8FwDieWBFcRK3jNYeG4ArE/HwtwMUxTS7B4b1CJWmobZTdiMG2R80AoDTlp/hStMATbdXdW3fBhnlwZuA1p43+IIcSuIQ9sDxGvZyBDYylSFx82kCYJ9zSDpaKY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ScK0MfYW; 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="ScK0MfYW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA1FBC4CEF4; Sun, 22 Jun 2025 12:58:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750597136; bh=Ygh4EXiwp2YXoTEH7jX4nu7C8/6De8xwJ1XjogF3BR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ScK0MfYWKPDgvbWd81ROUZJ66XHOAWa63OJIO9JH3ZhZnVkY9n8SrRCfxPzI8SjLo Rbk16grZwvLZ+/yzZF7zEmnGt1E8zkXtOIkjesSpMxWKur8SMOo2bV/HpvDrgRoHR7 qw81z+qfoctHWXRa7BdlVpw0ULMgvMopVRbGMr1oEaWy/QADe7YfaG6VxEDz1RAzpx by/iHS5Kp50rd7hx7GbAXgNOaGmS4JrtoST00BP4rFtkpsShvS9/5qeULAYHzBcqk1 TN9cnmQZ1+K1yTEYZ0ScXVZqTg3Z+hjpMW3uLGTOevz4HIRapGXy4xkFM6tsziLNaW hQzn9MVDg5GjQ== 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 , Xiangfei Ding , Alex Mantel Cc: Will Deacon , Peter Zijlstra , Mark Rutland , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 2/5] rust: make `Arc::into_unique_or_drop` associated function Date: Sun, 22 Jun 2025 13:57:28 +0100 Message-ID: <20250622125802.3224264-3-gary@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250622125802.3224264-1-gary@kernel.org> References: <20250622125802.3224264-1-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. 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 c7af0aa48a0a..09a471fea4da 100644 --- a/rust/kernel/sync/arc.rs +++ b/rust/kernel/sync/arc.rs @@ -320,7 +320,7 @@ 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()); @@ -336,18 +336,18 @@ 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 @@ -364,7 +364,7 @@ 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