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maybe_yield.hh
1/*
2 * This file is open source software, licensed to you under the terms
3 * of the Apache License, Version 2.0 (the "License"). See the NOTICE file
4 * distributed with this work for additional information regarding copyright
5 * ownership. You may not use this file except in compliance with the License.
6 *
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
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12 * software distributed under the License is distributed on an
13 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14 * KIND, either express or implied. See the License for the
15 * specific language governing permissions and limitations
16 * under the License.
17 */
18/*
19 * Copyright (C) 2021-present ScyllaDB
20 */
21
22#pragma once
23
24#include <concepts>
25#include <type_traits>
26#include <seastar/core/coroutine.hh>
27
28namespace seastar::coroutine {
29
30namespace internal {
31
32struct maybe_yield_awaiter final {
33 bool await_ready() const {
34 return !need_preempt();
35 }
36
37 template <typename T>
38 void await_suspend(std::coroutine_handle<T> h) {
39 schedule(&h.promise());
40 }
41
42 void await_resume() {
43 }
44};
45
46}
47
70class [[nodiscard("must co_await an maybe_yield() object")]] maybe_yield {
71public:
72 auto operator co_await() { return internal::maybe_yield_awaiter(); }
73};
74
75}
Definition: maybe_yield.hh:70