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//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// <atomic>
//
// template <class T>
// class atomic_ref;
//
// static constexpr bool is_always_lock_free;
// bool is_lock_free() const noexcept;
#include <atomic>
#include <cassert>
#include <concepts>
#include "test_macros.h"
#include "atomic_helpers.h"
template <typename T>
void check_always_lock_free(std::atomic_ref<T> const& a) {
using InfoT = LockFreeStatusInfo<T>;
constexpr std::same_as<const bool> decltype(auto) is_always_lock_free = std::atomic_ref<T>::is_always_lock_free;
// If we know the status of T for sure, validate the exact result of the function.
if constexpr (InfoT::status_known) {
constexpr LockFreeStatus known_status = InfoT::value;
if constexpr (known_status == LockFreeStatus::always) {
static_assert(is_always_lock_free, "is_always_lock_free is inconsistent with known lock-free status");
assert(a.is_lock_free() && "is_lock_free() is inconsistent with known lock-free status");
} else if constexpr (known_status == LockFreeStatus::never) {
static_assert(!is_always_lock_free, "is_always_lock_free is inconsistent with known lock-free status");
assert(!a.is_lock_free() && "is_lock_free() is inconsistent with known lock-free status");
} else {
assert(a.is_lock_free() || !a.is_lock_free()); // This is kinda dumb, but we might as well call the function once.
}
}
// In all cases, also sanity-check it based on the implication always-lock-free => lock-free.
if (is_always_lock_free) {
std::same_as<bool> decltype(auto) is_lock_free = a.is_lock_free();
assert(is_lock_free);
}
ASSERT_NOEXCEPT(a.is_lock_free());
}
#define CHECK_ALWAYS_LOCK_FREE(T) \
do { \
typedef T type; \
alignas(std::atomic_ref<type>::required_alignment) type obj{}; \
std::atomic_ref<type> a(obj); \
check_always_lock_free(a); \
} while (0)
void test() {
char c = 'x';
check_always_lock_free(std::atomic_ref<char>(c));
int i = 0;
check_always_lock_free(std::atomic_ref<int>(i));
float f = 0.f;
check_always_lock_free(std::atomic_ref<float>(f));
int* p = &i;
check_always_lock_free(std::atomic_ref<int*>(p));
CHECK_ALWAYS_LOCK_FREE(struct Empty{});
CHECK_ALWAYS_LOCK_FREE(struct OneInt { int i; });
CHECK_ALWAYS_LOCK_FREE(struct IntArr2 { int i[2]; });
CHECK_ALWAYS_LOCK_FREE(struct FloatArr3 { float i[3]; });
CHECK_ALWAYS_LOCK_FREE(struct LLIArr2 { long long int i[2]; });
CHECK_ALWAYS_LOCK_FREE(struct LLIArr4 { long long int i[4]; });
CHECK_ALWAYS_LOCK_FREE(struct LLIArr8 { long long int i[8]; });
CHECK_ALWAYS_LOCK_FREE(struct LLIArr16 { long long int i[16]; });
CHECK_ALWAYS_LOCK_FREE(struct Padding {
char c; /* padding */
long long int i;
});
CHECK_ALWAYS_LOCK_FREE(union IntFloat {
int i;
float f;
});
CHECK_ALWAYS_LOCK_FREE(enum class CharEnumClass : char{foo});
}
int main(int, char**) {
test();
return 0;
}
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