xref: /openbmc/sdbusplus/include/sdbusplus/async/stdexec/__detail/__inline_scheduler.hpp (revision 5cee9157)

/*
 * Copyright (c) 2021-2024 NVIDIA Corporation
 *
 * 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 "__basic_sender.hpp"
#include "__cpo.hpp"
#include "__env.hpp"
#include "__execution_fwd.hpp"
#include "__receivers.hpp"
#include "__schedulers.hpp"
#include "__utility.hpp"

namespace stdexec
{
namespace __inln
{
struct __schedule_t
{};

struct __scheduler
{
    using __t = __scheduler;
    using __id = __scheduler;

    template <class _Tag = __schedule_t>
    STDEXEC_ATTRIBUTE((host, device))
    STDEXEC_MEMFN_DECL(auto schedule)(this __scheduler)
    {
        return __make_sexpr<_Tag>();
    }

    auto query(get_forward_progress_guarantee_t) const noexcept
        -> forward_progress_guarantee
    {
        return forward_progress_guarantee::weakly_parallel;
    }

    auto operator==(const __scheduler&) const noexcept -> bool = default;
};

struct __env
{
    static constexpr bool query(__is_scheduler_affine_t) noexcept
    {
        return true;
    }

    constexpr auto query(get_completion_scheduler_t<set_value_t>) const noexcept
        -> __scheduler
    {
        return {};
    }
};
} // namespace __inln

template <>
struct __sexpr_impl<__inln::__schedule_t> : __sexpr_defaults
{
    static constexpr auto get_attrs = //
        [](__ignore) noexcept { return __inln::__env(); };

    static constexpr auto get_completion_signatures = //
        [](__ignore,
           __ignore = {}) noexcept -> completion_signatures<set_value_t()> {
        return {};
    };

    static constexpr auto start = //
        []<class _Receiver>(__ignore, _Receiver& __rcvr) noexcept -> void {
        stdexec::set_value(static_cast<_Receiver&&>(__rcvr));
    };
};

static_assert(__is_scheduler_affine<schedule_result_t<__inln::__scheduler>>);
} // namespace stdexec