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

445 lines
16 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/async_trace.hpp>
#include <unifex/blocking.hpp>
#include <unifex/get_stop_token.hpp>
#include <unifex/manual_lifetime.hpp>
#include <unifex/receiver_concepts.hpp>
#include <unifex/sender_concepts.hpp>
#include <unifex/tag_invoke.hpp>
#include <unifex/type_traits.hpp>
#include <unifex/type_list.hpp>
#include <unifex/std_concepts.hpp>
#include <exception>
#include <type_traits>
#include <utility>
#include <unifex/detail/prologue.hpp>
namespace unifex
{
namespace _seq
{
template <typename Predecessor, typename Successor, typename Receiver>
struct _op {
class type;
};
template <typename Predecessor, typename Successor, typename Receiver>
using operation = typename _op<
Predecessor,
Successor,
remove_cvref_t<Receiver>>::type;
template <typename Predecessor, typename Successor, typename Receiver>
struct _successor_receiver {
class type;
};
template <typename Predecessor, typename Successor, typename Receiver>
using successor_receiver =
typename _successor_receiver<
Predecessor,
Successor,
remove_cvref_t<Receiver>>::type;
template <typename Predecessor, typename Successor, typename Receiver>
class _successor_receiver<Predecessor, Successor, Receiver>::type final {
using successor_receiver = type;
using operation_type = operation<Predecessor, Successor, Receiver>;
public:
explicit type(operation_type* op) noexcept
: op_(op) {}
type(type&& other) noexcept
: op_(std::exchange(other.op_, nullptr)) {}
private:
template(typename CPO, typename R, typename... Args)
(requires
is_receiver_cpo_v<CPO> AND
same_as<R, successor_receiver> AND
is_callable_v<CPO, Receiver, Args...>)
friend auto tag_invoke(
CPO cpo,
R&& r,
Args&&... args) noexcept(is_nothrow_callable_v<
CPO,
Receiver,
Args...>)
-> callable_result_t<CPO, Receiver, Args...> {
return static_cast<CPO&&>(cpo)(
r.get_receiver_rvalue(), static_cast<Args&&>(args)...);
}
template(typename CPO, typename R)
(requires is_receiver_query_cpo_v<CPO> AND
same_as<R, successor_receiver> AND
is_callable_v<CPO, const Receiver&>)
friend auto tag_invoke(
CPO cpo,
const R& r) noexcept(is_nothrow_callable_v<
CPO,
const Receiver&>)
-> callable_result_t<CPO, const Receiver&> {
return static_cast<CPO&&>(cpo)(r.get_const_receiver());
}
template <typename Func>
friend void tag_invoke(
tag_t<visit_continuations>,
const successor_receiver& r,
Func&& func) {
std::invoke(func, r.get_const_receiver());
}
Receiver&& get_receiver_rvalue() noexcept {
return static_cast<Receiver&&>(op_->receiver_);
}
const Receiver& get_const_receiver() const noexcept {
return op_->receiver_;
}
operation_type* op_;
};
template <typename Predecessor, typename Successor, typename Receiver>
struct _predecessor_receiver {
class type;
};
template <typename Predecessor, typename Successor, typename Receiver>
using predecessor_receiver =
typename _predecessor_receiver<
Predecessor,
Successor,
remove_cvref_t<Receiver>>::type;
template <typename Predecessor, typename Successor, typename Receiver>
class _predecessor_receiver<Predecessor, Successor, Receiver>::type final {
using predecessor_receiver = type;
using operation_type = operation<Predecessor, Successor, Receiver>;
public:
explicit type(operation_type* op) noexcept
: op_(op) {}
type(type&& other) noexcept
: op_(std::exchange(other.op_, nullptr)) {}
void set_value() && noexcept {
// Take a copy of op_ before destroying predOp_ as this may end up
// destroying *this.
using successor_receiver_t =
successor_receiver<Predecessor, Successor, Receiver>;
auto* op = op_;
op->status_ = operation_type::status::empty;
unifex::deactivate_union_member(op->predOp_);
if constexpr (is_nothrow_connectable_v<Successor, successor_receiver_t>) {
unifex::activate_union_member_with(op->succOp_, [&]() noexcept {
return unifex::connect(
static_cast<Successor&&>(op->successor_), successor_receiver_t{op});
});
op->status_ = operation_type::status::successor_operation_constructed;
unifex::start(op->succOp_.get());
} else {
UNIFEX_TRY {
unifex::activate_union_member_with(op->succOp_, [&] {
return unifex::connect(
static_cast<Successor&&>(op->successor_), successor_receiver_t{op});
});
op->status_ = operation_type::status::successor_operation_constructed;
unifex::start(op->succOp_.get());
} UNIFEX_CATCH (...) {
unifex::set_error(
static_cast<Receiver&&>(op->receiver_),
std::current_exception());
}
}
}
template(typename Error)
(requires receiver<Receiver, Error>)
void set_error(Error&& error) && noexcept {
unifex::set_error(
static_cast<Receiver&&>(op_->receiver_),
static_cast<Error&&>(error));
}
void set_done() && noexcept {
unifex::set_done(static_cast<Receiver&&>(op_->receiver_));
}
private:
template(typename CPO, typename R)
(requires is_receiver_query_cpo_v<CPO> AND
same_as<R, predecessor_receiver> AND
is_callable_v<CPO, const Receiver&>)
friend auto tag_invoke(
CPO cpo,
const R& r) noexcept(is_nothrow_callable_v<
CPO,
const Receiver&>)
-> callable_result_t<CPO, const Receiver&> {
return static_cast<CPO&&>(cpo)(r.get_const_receiver());
}
template <typename Func>
friend void tag_invoke(
tag_t<visit_continuations>,
const predecessor_receiver& r,
Func&& func) {
std::invoke(func, r.get_const_receiver());
}
const Receiver& get_const_receiver() const noexcept {
return op_->receiver_;
}
operation_type* op_;
};
template <typename Predecessor, typename Successor, typename Receiver>
class _op<Predecessor, Successor, Receiver>::type {
using operation = type;
public:
template <typename Successor2, typename Receiver2>
explicit type(
Predecessor&& predecessor,
Successor2&& successor,
Receiver2&& receiver)
: successor_(static_cast<Successor2&&>(successor))
, receiver_(static_cast<Receiver&&>(receiver))
, status_(status::predecessor_operation_constructed) {
unifex::activate_union_member_with(predOp_, [&] {
return unifex::connect(
static_cast<Predecessor&&>(predecessor),
predecessor_receiver<Predecessor, Successor, Receiver>{this});
});
}
~type() {
switch (status_) {
case status::predecessor_operation_constructed:
unifex::deactivate_union_member(predOp_);
break;
case status::successor_operation_constructed:
unifex::deactivate_union_member(succOp_);
break;
case status::empty: break;
}
}
void start() & noexcept {
UNIFEX_ASSERT(status_ == status::predecessor_operation_constructed);
unifex::start(predOp_.get());
}
private:
friend predecessor_receiver<
Predecessor,
Successor,
Receiver>;
friend successor_receiver<
Predecessor,
Successor,
Receiver>;
Successor successor_;
Receiver receiver_;
enum class status {
empty,
predecessor_operation_constructed,
successor_operation_constructed
};
status status_;
union {
manual_lifetime<connect_result_t<
Predecessor,
predecessor_receiver<Predecessor, Successor, Receiver>>>
predOp_;
manual_lifetime<connect_result_t<
Successor,
successor_receiver<Predecessor, Successor, Receiver>>>
succOp_;
};
};
template <typename Predecessor, typename Successor>
struct _sender {
class type;
};
template <typename Predecessor, typename Successor>
using sender = typename _sender<
remove_cvref_t<Predecessor>,
remove_cvref_t<Successor>>::type;
template <typename Predecessor, typename Successor>
class _sender<Predecessor, Successor>::type {
using sender = type;
public:
template <
template <typename...> class Variant,
template <typename...> class Tuple>
using value_types =
sender_value_types_t<Successor, Variant, Tuple>;
template <template <typename...> class Variant>
using error_types =
typename concat_type_lists_unique_t<
sender_error_types_t<Predecessor, type_list>,
sender_error_types_t<Successor, type_list>,
type_list<std::exception_ptr>>::template apply<Variant>;
static constexpr bool sends_done =
sender_traits<Predecessor>::sends_done ||
sender_traits<Successor>::sends_done;
template(typename Predecessor2, typename Successor2)
(requires constructible_from<Predecessor, Predecessor2> AND
constructible_from<Successor, Successor2>)
explicit type(Predecessor2&& predecessor, Successor2&& successor)
noexcept(std::is_nothrow_constructible_v<Predecessor, Predecessor2> &&
std::is_nothrow_constructible_v<Successor, Successor2>)
: predecessor_(static_cast<Predecessor&&>(predecessor))
, successor_(static_cast<Successor&&>(successor)) {}
friend blocking_kind
tag_invoke(tag_t<blocking>, const sender& sender) {
const auto predBlocking = blocking(sender.predecessor_);
const auto succBlocking = blocking(sender.successor_);
if (predBlocking == blocking_kind::never) {
return blocking_kind::never;
} else if (
predBlocking == blocking_kind::always_inline &&
succBlocking == blocking_kind::always_inline) {
return blocking_kind::always_inline;
} else if (
(predBlocking == blocking_kind::always_inline ||
predBlocking == blocking_kind::always) &&
(succBlocking == blocking_kind::always_inline ||
succBlocking == blocking_kind::always)) {
return blocking_kind::always;
} else {
return blocking_kind::maybe;
}
}
template(typename Receiver, typename Sender)
(requires same_as<remove_cvref_t<Sender>, type> AND
constructible_from<Successor, member_t<Sender, Successor>> AND
sender_to<
member_t<Sender, Predecessor>,
predecessor_receiver<member_t<Sender, Predecessor>, Successor, Receiver>> AND
sender_to<
Successor,
successor_receiver<member_t<Sender, Predecessor>, Successor, Receiver>>)
friend auto tag_invoke(tag_t<unifex::connect>, Sender&& sender, Receiver&& receiver)
-> operation<member_t<Sender, Predecessor>, Successor, Receiver> {
return operation<member_t<Sender, Predecessor>, Successor, Receiver>{
static_cast<Sender&&>(sender).predecessor_,
static_cast<Sender&&>(sender).successor_,
(Receiver &&) receiver};
}
private:
UNIFEX_NO_UNIQUE_ADDRESS Predecessor predecessor_;
UNIFEX_NO_UNIQUE_ADDRESS Successor successor_;
};
} // namespace _seq
namespace _seq_cpo {
inline const struct _fn {
// Sequencing a single sender is just the same as returning the sender
// itself.
template <typename First>
remove_cvref_t<First> operator()(First&& first) const
noexcept(std::is_nothrow_constructible_v<remove_cvref_t<First>, First>) {
return static_cast<First&&>(first);
}
template(typename First, typename Second)
(requires sender<First> AND sender<Second> AND //
tag_invocable<_fn, First, Second>)
auto operator()(First&& first, Second&& second) const
noexcept(is_nothrow_tag_invocable_v<_fn, First, Second>)
-> tag_invoke_result_t<_fn, First, Second> {
return unifex::tag_invoke(
_fn{}, static_cast<First&&>(first), static_cast<Second&&>(second));
}
template(typename First, typename Second)
(requires sender<First> AND sender<Second> AND //
(!tag_invocable<_fn, First, Second>))
auto operator()(First&& first, Second&& second) const
noexcept(std::is_nothrow_constructible_v<
_seq::sender<First, Second>,
First,
Second>)
-> _seq::sender<First, Second> {
return _seq::sender<First, Second>{
static_cast<First&&>(first),
static_cast<Second&&>(second)};
}
template(typename First, typename Second, typename Third, typename... Rest)
(requires sender<First> AND sender<Second> AND sender<Third> AND
(sender<Rest> &&...) AND tag_invocable<_fn, First, Second, Third, Rest...>)
auto operator()(First&& first, Second&& second, Third&& third, Rest&&... rest) const
noexcept(is_nothrow_tag_invocable_v<_fn, First, Second, Third, Rest...>)
-> tag_invoke_result_t<_fn, First, Second, Third, Rest...> {
return unifex::tag_invoke(
_fn{},
static_cast<First&&>(first),
static_cast<Second&&>(second),
static_cast<Third&&>(third),
static_cast<Rest&&>(rest)...);
}
template(typename First, typename Second, typename Third, typename... Rest)
(requires sender<First> AND sender<Second> AND sender<Third> AND
(sender<Rest> &&...) AND (!tag_invocable<_fn, First, Second, Third, Rest...>))
auto operator()(First&& first, Second&& second, Third&& third, Rest&&... rest) const
noexcept(is_nothrow_callable_v<_fn, First, Second> &&
is_nothrow_callable_v<
_fn,
callable_result_t<_fn, First, Second>,
Third,
Rest...>)
-> callable_result_t<
_fn,
callable_result_t<_fn, First, Second>,
Third,
Rest...> {
// Fall-back to pair-wise invocation of the sequence() CPO.
return (*this)(
(*this)(static_cast<First&&>(first), static_cast<Second&&>(second)),
static_cast<Third&&>(third),
static_cast<Rest&&>(rest)...);
}
} sequence{};
} // _seq_cpo
using _seq_cpo::sequence;
} // namespace unifex
#include <unifex/detail/epilogue.hpp>