| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // 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 <utility> |
| #include <vector> |
| |
| #include "arrow/status.h" |
| #include "arrow/util/thread_pool.h" |
| |
| namespace arrow { |
| namespace internal { |
| |
| // A parallelizer that takes a `Status(int)` function and calls it with |
| // arguments between 0 and `num_tasks - 1`, on an arbitrary number of threads. |
| |
| template <class FUNCTION> |
| Status ParallelFor(int num_tasks, FUNCTION&& func, |
| Executor* executor = internal::GetCpuThreadPool()) { |
| std::vector<Future<>> futures(num_tasks); |
| |
| for (int i = 0; i < num_tasks; ++i) { |
| ARROW_ASSIGN_OR_RAISE(futures[i], executor->Submit(func, i)); |
| } |
| auto st = Status::OK(); |
| for (auto& fut : futures) { |
| st &= fut.status(); |
| } |
| return st; |
| } |
| |
| // A parallelizer that takes a `Status(int)` function and calls it with |
| // arguments between 0 and `num_tasks - 1`, in sequence or in parallel, |
| // depending on the input boolean. |
| |
| template <class FUNCTION> |
| Status OptionalParallelFor(bool use_threads, int num_tasks, FUNCTION&& func, |
| Executor* executor = internal::GetCpuThreadPool()) { |
| if (use_threads) { |
| return ParallelFor(num_tasks, std::forward<FUNCTION>(func), executor); |
| } else { |
| for (int i = 0; i < num_tasks; ++i) { |
| RETURN_NOT_OK(func(i)); |
| } |
| return Status::OK(); |
| } |
| } |
| |
| } // namespace internal |
| } // namespace arrow |