From 2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Mon, 24 Aug 2026 01:18:14 +0900 Subject: coccinelle: alloc_cast: drop removed allocators - pci_alloc_consistent() and pci_zalloc_consistent() were removed by commit 7968778914e5 ("PCI: Remove the deprecated "pci-dma-compat.h" API") - kmem_alloc() was removed by commit f078d4ea8276 ("xfs: convert kmem_alloc() to kmalloc()") - kmem_zalloc() was removed by commit 10634530f7ba ("xfs: convert kmem_zalloc() to kzalloc()") - kmem_zone_alloc() and kmem_zone_zalloc() were removed by commit bae633a4a283 ("xfs: remove xfs_zone_{alloc,zalloc} helpers") So drop them from the rules. No functional change. Signed-off-by: Sang-Heon Jeon Signed-off-by: Julia Lawall --- rust/syn/thread.rs | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 rust/syn/thread.rs (limited to 'rust/syn/thread.rs') diff --git a/rust/syn/thread.rs b/rust/syn/thread.rs new file mode 100644 index 000000000..4165a173d --- /dev/null +++ b/rust/syn/thread.rs @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use std::fmt::{self, Debug}; +use std::thread::{self, ThreadId}; + +/// ThreadBound is a Sync-maker and Send-maker that allows accessing a value +/// of type T only from the original thread on which the ThreadBound was +/// constructed. +pub(crate) struct ThreadBound { + value: T, + thread_id: ThreadId, +} + +unsafe impl Sync for ThreadBound {} + +// Send bound requires Copy, as otherwise Drop could run in the wrong place. +// +// Today Copy and Drop are mutually exclusive so `T: Copy` implies `T: !Drop`. +// This impl needs to be revisited if that restriction is relaxed in the future. +unsafe impl Send for ThreadBound {} + +impl ThreadBound { + pub(crate) fn new(value: T) -> Self { + ThreadBound { + value, + thread_id: thread::current().id(), + } + } + + pub(crate) fn get(&self) -> Option<&T> { + if thread::current().id() == self.thread_id { + Some(&self.value) + } else { + None + } + } +} + +impl Debug for ThreadBound { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + match self.get() { + Some(value) => Debug::fmt(value, formatter), + None => formatter.write_str("unknown"), + } + } +} + +// Copy the bytes of T, even if the currently running thread is the "wrong" +// thread. This is fine as long as the original thread is not simultaneously +// mutating this value via interior mutability, which would be a data race. +// +// Currently `T: Copy` is sufficient to guarantee that T contains no interior +// mutability, because _all_ interior mutability in Rust is built on +// std::cell::UnsafeCell, which has no Copy impl. This impl needs to be +// revisited if that restriction is relaxed in the future. +impl Copy for ThreadBound {} + +impl Clone for ThreadBound { + fn clone(&self) -> Self { + *self + } +} -- cgit v1.3.1