pitrou commented on a change in pull request #9095: URL: https://github.com/apache/arrow/pull/9095#discussion_r565169302
########## File path: cpp/src/arrow/csv/reader_test.cc ########## @@ -0,0 +1,169 @@ +// 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. + +#include <cstdint> +#include <string> +#include <thread> +#include <utility> +#include <vector> + +#include <gtest/gtest.h> + +#include "arrow/csv/options.h" +#include "arrow/csv/reader.h" +#include "arrow/csv/test_common.h" +#include "arrow/io/interfaces.h" +#include "arrow/status.h" +#include "arrow/table.h" +#include "arrow/testing/gtest_util.h" +#include "arrow/util/future.h" +#include "arrow/util/thread_pool.h" + +namespace arrow { +namespace csv { + +void StressTableReader( + std::function<Result<std::shared_ptr<TableReader>>(std::shared_ptr<io::InputStream>)> + reader_factory) { + const int NTASKS = 100; + const int NROWS = 1000; + ASSERT_OK_AND_ASSIGN(auto table_buffer, MakeSampleCsvBuffer(NROWS)); + + std::vector<Future<std::shared_ptr<Table>>> task_futures(NTASKS); + for (int i = 0; i < NTASKS; i++) { + auto input = std::make_shared<io::BufferReader>(table_buffer); + ASSERT_OK_AND_ASSIGN(auto reader, reader_factory(input)); + task_futures[i] = reader->ReadAsync(); + } + auto combined_future = All(task_futures); + combined_future.Wait(); + + ASSERT_OK_AND_ASSIGN(std::vector<Result<std::shared_ptr<Table>>> results, + combined_future.result()); + for (auto&& result : results) { + ASSERT_OK_AND_ASSIGN(auto table, result); + ASSERT_EQ(NROWS, table->num_rows()); + } +} + +void TestNestedParallelism( + std::shared_ptr<internal::ThreadPool> thread_pool, + std::function<Result<std::shared_ptr<TableReader>>(std::shared_ptr<io::InputStream>)> + reader_factory) { + const int NROWS = 1000; + ASSERT_OK_AND_ASSIGN(auto table_buffer, MakeSampleCsvBuffer(NROWS)); + auto input = std::make_shared<io::BufferReader>(table_buffer); + ASSERT_OK_AND_ASSIGN(auto reader, reader_factory(input)); + + Future<std::shared_ptr<Table>> table_future; + + auto read_task = [&reader, &table_future]() mutable { + table_future = reader->ReadAsync(); + return Status::OK(); + }; + ASSERT_OK_AND_ASSIGN(auto future, thread_pool->Submit(read_task)); + ASSERT_TRUE(future.Wait(1)); + + if (future.is_finished()) { + ASSERT_TRUE(table_future.Wait(1)); + if (table_future.is_finished()) { + ASSERT_OK_AND_ASSIGN(auto table, table_future.result()); + ASSERT_EQ(table->num_rows(), NROWS); + } + } +} // namespace csv + +TEST(SerialReaderTests, Stress) { + auto task_factory = [](std::shared_ptr<io::InputStream> input_stream) { + return TableReader::Make(default_memory_pool(), io::AsyncContext(), input_stream, + ReadOptions::Defaults(), ParseOptions::Defaults(), + ConvertOptions::Defaults()); + }; + StressTableReader(task_factory); +} + +TEST(SerialReaderTests, NestedParallelism) { + ASSERT_OK_AND_ASSIGN(auto thread_pool, internal::ThreadPool::Make(1)); + auto task_factory = [](std::shared_ptr<io::InputStream> input_stream) { + return TableReader::Make(default_memory_pool(), io::AsyncContext(), input_stream, + ReadOptions::Defaults(), ParseOptions::Defaults(), + ConvertOptions::Defaults()); + }; + TestNestedParallelism(thread_pool, task_factory); +} + +TEST(ThreadedReaderTests, Stress) { + ASSERT_OK_AND_ASSIGN(auto thread_pool, internal::ThreadPool::Make(1)); + auto task_factory = [&thread_pool](std::shared_ptr<io::InputStream> input_stream) + -> Result<std::shared_ptr<TableReader>> { + ReadOptions read_options = ReadOptions::Defaults(); + read_options.use_threads = true; + read_options.legacy_blocking_reads = true; + auto table_reader = TableReader::Make( + default_memory_pool(), io::AsyncContext(thread_pool.get()), input_stream, Review comment: > However, it sounds like the existing definition is "This is the context on which the I/O operation should run". However, I think that should be owned by the FS. Hmm, you may be right that the FS and/or stream implementation should own it. Can you open a JIRA for that? > In my mind ctx is "This is the context on which work should resume when the I/O operation completes". That would be a weird API IMHO. You generally pass function parameters for what gets done in the function, not what happens when the function finishes executing. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
