//===----------------------------------------------------------------------===//
//
// 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
// XFAIL: availability-synchronization_library-missing
// XFAIL: !has-64-bit-atomics
// void wait(T old, memory_order order = memory_order::seq_cst) const volatile noexcept;
// void wait(T old, memory_order order = memory_order::seq_cst) const noexcept;
#include <atomic>
#include <cassert>
#include <concepts>
#include <type_traits>
#include <utility>
#include <vector>
#include "test_helper.h"
#include "test_macros.h"
#ifndef TEST_HAS_NO_THREADS
# include "make_test_thread.h"
# include <thread>
#endif
template <class T>
concept HasVolatileWait = requires(volatile std::atomic<T>& a, T t) { a.wait(T()); };
template <class T, template <class> class MaybeVolatile = std::type_identity_t>
void test_impl() {
// Uncomment the test after P1831R1 is implemented
// static_assert(HasVolatileWait<T> == std::atomic<T>::is_always_lock_free);
static_assert(noexcept(std::declval<MaybeVolatile<std::atomic<T>>&>().wait(T())));
// wait with different value
{
MaybeVolatile<std::atomic<T>> a(T(3.1));
a.wait(T(1.1), std::memory_order::relaxed);
}
#ifndef TEST_HAS_NO_THREADS
// equal at the beginning and changed later
// bug?? wait can also fail for long double ??
// should x87 80bit long double work at all?
if constexpr (!std::same_as<T, long double>) {
for (auto i = 0; i < 100; ++i) {
const T old = T(3.1);
MaybeVolatile<std::atomic<T>> a(old);
std::atomic_bool started = false;
bool done = false;
auto t = support::make_test_thread([&a, &started, old, &done] {
started.store(true, std::memory_order::relaxed);
a.wait(old);
// likely to fail if wait did not block
assert(done);
});
while (!started.load(std::memory_order::relaxed)) {
std::this_thread::yield();
}
std::this_thread::sleep_for(std::chrono::milliseconds(1));
done = true;
a.store(T(9.9));
a.notify_all();
t.join();
}
}
#endif
// memory_order::acquire
{
auto store = [](MaybeVolatile<std::atomic<T>>& x, T, T new_val) { x.store(new_val, std::memory_order::release); };
auto load = [](MaybeVolatile<std::atomic<T>>& x) {
auto result = x.load(std::memory_order::relaxed);
x.wait(T(9999.999), std::memory_order::acquire);
return result;
};
test_acquire_release<T, MaybeVolatile>(store, load);
}
// memory_order::seq_cst
{
auto store = [](MaybeVolatile<std::atomic<T>>& x, T, T new_val) { x.store(new_val); };
auto load_no_arg = [](MaybeVolatile<std::atomic<T>>& x) {
auto result = x.load(std::memory_order::relaxed);
x.wait(T(9999.999));
return result;
};
auto load_with_order = [](MaybeVolatile<std::atomic<T>>& x) {
auto result = x.load(std::memory_order::relaxed);
x.wait(T(9999.999), std::memory_order::seq_cst);
return result;
};
test_seq_cst<T, MaybeVolatile>(store, load_no_arg);
test_seq_cst<T, MaybeVolatile>(store, load_with_order);
}
}
template <class T>
void test() {
test_impl<T>();
if constexpr (std::atomic<T>::is_always_lock_free) {
test_impl<T, std::add_volatile_t>();
}
}
int main(int, char**) {
test<float>();
test<double>();
// TODO https://github.com/llvm/llvm-project/issues/47978
// test<long double>();
return 0;
}