[libcxx-commits] [libcxx] [libc++] Implement P2545R4 Read-Copy Update (RCU) (PR #175451)

[via libcxx-commits]

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+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___RCU_RCU_LIST_H
+#define _LIBCPP___RCU_RCU_LIST_H
+
+#include <__config>
+#include <__functional/function.h>
+#include <__rcu/rcu_domain.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER >= 26 && _LIBCPP_HAS_THREADS && _LIBCPP_HAS_EXPERIMENTAL_RCU
+
+struct __rcu_node {
+  function<void()> __callback_{};
+  __rcu_node* __next_ = nullptr;
+};
+
+class __rcu_singly_list_view {
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huixie90 wrote:

The `rcu_obj_base::retire` is `noexcept`, which suggests that we should not allocate when we push new nodes into the queue. I think it is easier to keep the list intrusive so that we don't have to allocate memory when the user needs to allocate memory themselves outside rcu

https://github.com/llvm/llvm-project/pull/175451