2025-01-12 19:51:34 +08:00

149 lines
4.6 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* Licensed under the Apache License Version 2.0 with LLVM Exceptions
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* https://llvm.org/LICENSE.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <unifex/config.hpp>
#include <unifex/get_allocator.hpp>
#include <unifex/receiver_concepts.hpp>
#include <unifex/scope_guard.hpp>
#include <unifex/sender_concepts.hpp>
#include <unifex/tag_invoke.hpp>
#include <unifex/bind_back.hpp>
#include <memory>
#include <type_traits>
#include <unifex/detail/prologue.hpp>
namespace unifex {
namespace _alloc {
template <typename Operation, typename Allocator>
struct _op {
class type;
};
template <typename Operation, typename Allocator>
using operation = typename _op<Operation, Allocator>::type;
template <typename Operation, typename Allocator>
class _op<Operation, Allocator>::type {
using operation = type;
using allocator_t = typename std::allocator_traits<
Allocator>::template rebind_alloc<Operation>;
public:
template <typename Sender, typename Receiver>
explicit type(Sender&& s, Receiver&& r)
: allocator_(get_allocator(r)) {
using allocator_traits = std::allocator_traits<allocator_t>;
Operation* op = allocator_traits::allocate(allocator_, 1);
scope_guard freeOnError = [&]() noexcept {
allocator_traits::deallocate(allocator_, op, 1);
};
op_ = ::new (static_cast<void*>(op))
Operation(connect((Sender &&) s, (Receiver &&) r));
freeOnError.release();
}
~type() {
op_->~Operation();
std::allocator_traits<allocator_t>::deallocate(allocator_, op_, 1);
}
friend void tag_invoke(tag_t<start>, operation& op) noexcept {
start(*op.op_);
}
private:
Operation* op_;
UNIFEX_NO_UNIQUE_ADDRESS allocator_t allocator_;
};
template <typename Sender>
struct _sender {
class type;
};
template <typename Sender>
using sender = typename _sender<remove_cvref_t<Sender>>::type;
template <typename Sender>
class _sender<Sender>::type {
using sender = type;
public:
template <
template <typename...> class Variant,
template <typename...> class Tuple>
using value_types = sender_value_types_t<Sender, Variant, Tuple>;
template <template <typename...> class Variant>
using error_types = sender_error_types_t<Sender, Variant>;
static constexpr bool sends_done = sender_traits<Sender>::sends_done;
template(typename Self, typename Receiver)
(requires same_as<remove_cvref_t<Self>, type> AND
receiver<Receiver>)
friend auto tag_invoke(tag_t<connect>, Self&& s, Receiver&& r)
-> operation<
connect_result_t<member_t<Self, Sender>, Receiver>,
remove_cvref_t<get_allocator_t<Receiver>>> {
return operation<
connect_result_t<member_t<Self, Sender>, Receiver>,
remove_cvref_t<get_allocator_t<Receiver>>>{
static_cast<Self&&>(s).sender_, (Receiver &&) r};
}
Sender sender_;
};
} // namespace _alloc
namespace _alloc_cpo {
inline const struct _fn {
private:
template <typename Sender>
using _result_t =
typename conditional_t<
tag_invocable<_fn, Sender>,
meta_tag_invoke_result<_fn>,
meta_quote1<_alloc::sender>>::template apply<Sender>;
public:
template(typename Sender)
(requires tag_invocable<_fn, Sender>)
auto operator()(Sender&& predecessor) const
noexcept(is_nothrow_tag_invocable_v<_fn, Sender>)
-> _result_t<Sender> {
return unifex::tag_invoke(_fn{}, (Sender&&) predecessor);
}
template(typename Sender)
(requires (!tag_invocable<_fn, Sender>))
auto operator()(Sender&& predecessor) const
noexcept(std::is_nothrow_constructible_v<_alloc::sender<Sender>, Sender>)
-> _result_t<Sender> {
return _alloc::sender<Sender>{(Sender &&) predecessor};
}
constexpr auto operator()() const
noexcept(is_nothrow_callable_v<
tag_t<bind_back>, _fn>)
-> bind_back_result_t<_fn> {
return bind_back(*this);
}
} allocate{};
} // namespace _alloc_cpo
using _alloc_cpo::allocate;
} // namespace unifex
#include <unifex/detail/epilogue.hpp>