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

[via libcxx-commits]

================
@@ -0,0 +1,91 @@
+// -*- 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_DOMAIN_H
+#define _LIBCPP___RCU_RCU_DOMAIN_H
+
+#include <__config>
+#include <__functional/function.h>
+#include <__memory/unique_ptr.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+_LIBCPP_BEGIN_EXPLICIT_ABI_ANNOTATIONS
+
+#if _LIBCPP_STD_VER >= 26 && _LIBCPP_HAS_THREADS && _LIBCPP_HAS_EXPERIMENTAL_RCU
+
+struct __rcu_node {
+  function<void()> __callback_{};
+  __rcu_node* __next_ = nullptr;
+
+  _LIBCPP_HIDE_FROM_ABI __rcu_node() {}
+  _LIBCPP_HIDE_FROM_ABI ~__rcu_node() {}
+};
+
+class _LIBCPP_EXPORTED_FROM_ABI rcu_domain {
+  class __impl;
+  unique_ptr<__impl> __pimpl_;
+
+  template <class, class>
+  friend class rcu_obj_base;
+
+  friend rcu_domain& rcu_default_domain() noexcept;
+  friend void rcu_synchronize(rcu_domain&) noexcept;
+
+  static rcu_domain& __rcu_default_domain() noexcept;
+
+  template <class _Tp, class _Dp = default_delete<_Tp>>
+  _LIBCPP_HIDE_FROM_ABI void __rcu_retire_hidden_friend(_Tp* __tp, _Dp __deleter, rcu_domain& __dom) {
+    auto* __node        = new __rcu_node();
+    __node->__callback_ = [__tp, __deleter = std::move(__deleter)]() mutable { __deleter(__tp); };
----------------
huixie90 wrote:

Indeed, I did some refactoring and we no longer need this lambda

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