Release Cosmopolitan v3.6.0

This release is an atomic upgrade to GCC 14.1.0 with C23 and C++23

third_party/libcxx/memory.cpp

@@ -0,0 +1,148 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include <__config>
+#ifdef _LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS
+#  define _LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS
+#endif
+
+#include <memory>
+
+#ifndef _LIBCPP_HAS_NO_THREADS
+#  include <mutex>
+#  include <thread>
+#  if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB)
+#    pragma comment(lib, "pthread")
+#  endif
+#endif
+
+#include "atomic_support.h"
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+bad_weak_ptr::~bad_weak_ptr() noexcept {}
+
+const char* bad_weak_ptr::what() const noexcept { return "bad_weak_ptr"; }
+
+__shared_count::~__shared_count() {}
+
+__shared_weak_count::~__shared_weak_count() {}
+
+#if defined(_LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS)
+void __shared_count::__add_shared() noexcept { __libcpp_atomic_refcount_increment(__shared_owners_); }
+
+bool __shared_count::__release_shared() noexcept {
+  if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
+    __on_zero_shared();
+    return true;
+  }
+  return false;
+}
+
+void __shared_weak_count::__add_shared() noexcept { __shared_count::__add_shared(); }
+
+void __shared_weak_count::__add_weak() noexcept { __libcpp_atomic_refcount_increment(__shared_weak_owners_); }
+
+void __shared_weak_count::__release_shared() noexcept {
+  if (__shared_count::__release_shared())
+    __release_weak();
+}
+#endif // _LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS
+
+void __shared_weak_count::__release_weak() noexcept {
+  // NOTE: The acquire load here is an optimization of the very
+  // common case where a shared pointer is being destructed while
+  // having no other contended references.
+  //
+  // BENEFIT: We avoid expensive atomic stores like XADD and STREX
+  // in a common case.  Those instructions are slow and do nasty
+  // things to caches.
+  //
+  // IS THIS SAFE?  Yes.  During weak destruction, if we see that we
+  // are the last reference, we know that no-one else is accessing
+  // us. If someone were accessing us, then they would be doing so
+  // while the last shared / weak_ptr was being destructed, and
+  // that's undefined anyway.
+  //
+  // If we see anything other than a 0, then we have possible
+  // contention, and need to use an atomicrmw primitive.
+  // The same arguments don't apply for increment, where it is legal
+  // (though inadvisable) to share shared_ptr references between
+  // threads, and have them all get copied at once.  The argument
+  // also doesn't apply for __release_shared, because an outstanding
+  // weak_ptr::lock() could read / modify the shared count.
+  if (__libcpp_atomic_load(&__shared_weak_owners_, _AO_Acquire) == 0) {
+    // no need to do this store, because we are about
+    // to destroy everything.
+    //__libcpp_atomic_store(&__shared_weak_owners_, -1, _AO_Release);
+    __on_zero_shared_weak();
+  } else if (__libcpp_atomic_refcount_decrement(__shared_weak_owners_) == -1)
+    __on_zero_shared_weak();
+}
+
+__shared_weak_count* __shared_weak_count::lock() noexcept {
+  long object_owners = __libcpp_atomic_load(&__shared_owners_);
+  while (object_owners != -1) {
+    if (__libcpp_atomic_compare_exchange(&__shared_owners_, &object_owners, object_owners + 1))
+      return this;
+  }
+  return nullptr;
+}
+
+const void* __shared_weak_count::__get_deleter(const type_info&) const noexcept { return nullptr; }
+
+#if !defined(_LIBCPP_HAS_NO_THREADS)
+
+static constexpr std::size_t __sp_mut_count                = 32;
+static constinit __libcpp_mutex_t mut_back[__sp_mut_count] = {
+    _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
+    _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
+    _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
+    _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
+    _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
+    _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
+    _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
+    _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER};
+
+constexpr __sp_mut::__sp_mut(void* p) noexcept : __lx_(p) {}
+
+void __sp_mut::lock() noexcept {
+  auto m = static_cast<__libcpp_mutex_t*>(__lx_);
+  __libcpp_mutex_lock(m);
+}
+
+void __sp_mut::unlock() noexcept { __libcpp_mutex_unlock(static_cast<__libcpp_mutex_t*>(__lx_)); }
+
+__sp_mut& __get_sp_mut(const void* p) {
+  static constinit __sp_mut muts[__sp_mut_count] = {
+      &mut_back[0],  &mut_back[1],  &mut_back[2],  &mut_back[3],  &mut_back[4],  &mut_back[5],  &mut_back[6],
+      &mut_back[7],  &mut_back[8],  &mut_back[9],  &mut_back[10], &mut_back[11], &mut_back[12], &mut_back[13],
+      &mut_back[14], &mut_back[15], &mut_back[16], &mut_back[17], &mut_back[18], &mut_back[19], &mut_back[20],
+      &mut_back[21], &mut_back[22], &mut_back[23], &mut_back[24], &mut_back[25], &mut_back[26], &mut_back[27],
+      &mut_back[28], &mut_back[29], &mut_back[30], &mut_back[31]};
+  return muts[hash<const void*>()(p) & (__sp_mut_count - 1)];
+}
+
+#endif // !defined(_LIBCPP_HAS_NO_THREADS)
+
+void* align(size_t alignment, size_t size, void*& ptr, size_t& space) {
+  void* r = nullptr;
+  if (size <= space) {
+    char* p1 = static_cast<char*>(ptr);
+    char* p2 = reinterpret_cast<char*>(reinterpret_cast<uintptr_t>(p1 + (alignment - 1)) & -alignment);
+    size_t d = static_cast<size_t>(p2 - p1);
+    if (d <= space - size) {
+      r   = p2;
+      ptr = r;
+      space -= d;
+    }
+  }
+  return r;
+}
+
+_LIBCPP_END_NAMESPACE_STD