1 /**
2 * Copyright 2021 Huawei Technologies Co., Ltd
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef MINDSPORE_CORE_MINDRT_INCLUDE_ASYNC_COLLECT_H
18 #define MINDSPORE_CORE_MINDRT_INCLUDE_ASYNC_COLLECT_H
19
20 #include <future>
21 #include <iostream>
22 #include <list>
23 #include <memory>
24 #include <tuple>
25 #include "async/common.h"
26 #include "async/future.h"
27 #include "async/defer.h"
28 #include "async/spinlock.h"
29 #include "actor/actor.h"
30 #include "mindrt/include/mindrt.hpp"
31
32 namespace mindspore {
33
34 template <typename T>
35 class Future;
36
37 template <typename T>
38 class Promise;
39
40 template <typename T>
41 class Collected;
42
43 template <typename T>
44 class Collected {
45 public:
Collected(const std::list<Future<T>> & f,Promise<std::list<T>> * p)46 Collected(const std::list<Future<T>> &f, Promise<std::list<T>> *p) : futures(f), promise(p), ready(0) {}
47
~Collected()48 virtual ~Collected() {
49 delete promise;
50 promise = nullptr;
51 }
52
53 Collected(const Collected &) = delete;
54 Collected(Collected &&) = default;
55
56 Collected &operator=(const Collected &) = delete;
57 Collected &operator=(Collected &&) = default;
58
59 public:
Discarded()60 void Discarded() {
61 auto iter = futures.begin();
62 for (; iter != futures.end(); ++iter) {
63 iter->SetFailed(MindrtStatus::KERROR);
64 }
65 }
66
Waited(const Future<T> & future)67 void Waited(const Future<T> &future) {
68 if (future.IsError()) {
69 promise->SetFailed(future.GetErrorCode());
70 } else if (future.IsOK()) {
71 ready.fetch_add(1);
72 if (ready.load() == futures.size()) {
73 std::list<T> values;
74 auto iter = futures.begin();
75 for (; iter != futures.end(); ++iter) {
76 values.push_back(iter->Get());
77 }
78 promise->SetValue(values);
79 }
80 }
81 }
82
83 private:
84 const std::list<Future<T>> futures;
85 Promise<std::list<T>> *promise;
86 std::atomic_ulong ready;
87 };
88
89 template <typename T>
Collect(const std::list<Future<T>> & futures)90 inline Future<std::list<T>> Collect(const std::list<Future<T>> &futures) {
91 if (futures.empty()) return Future<std::list<T>>(std::list<T>());
92
93 Promise<std::list<T>> *promise = new (std::nothrow) Promise<std::list<T>>();
94 MINDRT_OOM_EXIT(promise);
95 std::shared_ptr<Collected<T>> collect = std::make_shared<Collected<T>>(futures, promise);
96
97 for (auto iter = futures.begin(); iter != futures.end(); ++iter) {
98 iter->OnComplete(Defer(collect, &Collected<T>::Waited, std::placeholders::_1));
99 }
100
101 Future<std::list<T>> future = promise->GetFuture();
102 future.OnComplete(Defer(collect, &Collected<T>::Discarded));
103
104 return future;
105 }
106
107 template <typename... Ts>
Collect(const Future<Ts> &...futures)108 Future<std::tuple<Ts...>> Collect(const Future<Ts> &... futures) {
109 std::list<Future<Nothing>> wrappers = {futures.Then([]() { return Nothing(); })...};
110
111 auto f = [](const Future<Ts> &... futures) { return std::make_tuple(futures.Get()...); };
112
113 return Collect(wrappers).Then(std::bind(f, futures...));
114 }
115
116 }; // namespace mindspore
117
118 #endif
119