From 1bd45f39ed1d6a1c7140f957b6c9a3e8015c0f67 Mon Sep 17 00:00:00 2001 From: Scott Young Date: Thu, 7 Nov 2024 19:18:23 -0800 Subject: [PATCH] add bufferPool for nimble parallel writer (#103) Summary: change the buffer class to a bufferPool to handle multihreaded buffers without mutexes Differential Revision: D64774959 --- dwio/nimble/common/Buffer.h | 103 ++++++++++- dwio/nimble/common/tests/BufferPoolTests.cpp | 178 +++++++++++++++++++ dwio/nimble/velox/FieldWriter.cpp | 7 +- dwio/nimble/velox/FieldWriter.h | 23 ++- dwio/nimble/velox/VeloxWriter.cpp | 18 +- dwio/nimble/velox/VeloxWriter.h | 1 - dwio/nimble/velox/VeloxWriterOptions.h | 2 +- dwio/nimble/velox/tests/VeloxWriterTests.cpp | 14 +- 8 files changed, 307 insertions(+), 39 deletions(-) create mode 100644 dwio/nimble/common/tests/BufferPoolTests.cpp diff --git a/dwio/nimble/common/Buffer.h b/dwio/nimble/common/Buffer.h index 6408ca5..5c2fe8f 100644 --- a/dwio/nimble/common/Buffer.h +++ b/dwio/nimble/common/Buffer.h @@ -15,6 +15,8 @@ */ #pragma once +#include "dwio/nimble/common/Exceptions.h" +#include "folly/concurrency/DynamicBoundedQueue.h" #include "velox/buffer/Buffer.h" #include "velox/common/memory/Memory.h" @@ -33,12 +35,11 @@ // and so on namespace facebook::nimble { +using MemoryPool = facebook::velox::memory::MemoryPool; -// Internally manages memory in chunks. Releases memory only upon destruction. +// Internally manages memory in chunks. releases memory when destroyed // Buffer is NOT threadsafe: external locking is required. class Buffer { - using MemoryPool = facebook::velox::memory::MemoryPool; - public: explicit Buffer( MemoryPool& memoryPool, @@ -52,7 +53,6 @@ class Buffer { // to, and guarantees for the lifetime of *this that that region will remain // valid. Does NOT guarantee that the region is initially 0'd. char* reserve(uint64_t bytes) { - std::scoped_lock l(mutex_); if (reserveEnd_ + bytes <= chunkEnd_) { pos_ = reserveEnd_; reserveEnd_ += bytes; @@ -98,11 +98,96 @@ class Buffer { char* reserveEnd_; std::vector chunks_; MemoryPool& memoryPool_; - // NOTE: this is temporary fix, to quickly enable parallel access to the - // buffer class. In the near future, we are going to templetize this class to - // produce a concurrent and a non-concurrent variants, and change the call - // sites to use each variant when needed. - std::mutex mutex_; +}; + +using BufferPtr = std::unique_ptr; + +// Manages a pool of buffers. Buffers are returned to the pool when released. +// maxPoolSize should be set to at least 90% of capacity for performance +class BufferPool { + public: + explicit BufferPool( + MemoryPool& memoryPool, + std::chrono::milliseconds timeout = std::chrono::milliseconds(1000 * 10), + size_t maxPoolSize = std::thread::hardware_concurrency(), + size_t initialBufferCount = 20, // should be enough for 1 stripe + uint64_t initialChunkSize = kMinChunkSize) + : defaultInitialChunkSize_{initialChunkSize}, + timeout_{timeout}, + bufferQueue_{maxPoolSize}, + memoryPool_{memoryPool} { + NIMBLE_CHECK(maxPoolSize > 0, "max pool size must be > 0") + NIMBLE_CHECK(timeout_.count() > 0, "timeout must be > 0") + NIMBLE_CHECK( + initialBufferCount <= maxPoolSize, + "initial pool size must be <= max pool size"); + + for (size_t i = 0; i < initialBufferCount; ++i) { + addBuffer(newBuffer()); + } + } + + ~BufferPool() { + deleteBufferPool(); + } + + MemoryPool& getMemoryPool() { + return memoryPool_; + } + + // Releases the buffer back to the pool. + void addBuffer(BufferPtr buffer) { + const auto status = + bufferQueue_.try_enqueue_for(std::move(buffer), timeout_); + if (!status) { + // If the buffer queue is full, we just delete the buffer. + buffer.reset(); + } + } + + // Reserves a buffer from the pool. Adds a new buffer to the pool + // while there are buffers available + BufferPtr reserveBuffer() { + if (bufferQueue_.empty()) { + return newBuffer(); + } + + BufferPtr buffer; + const auto status = bufferQueue_.try_dequeue_for(buffer, timeout_); + if (!status) { + NIMBLE_UNREACHABLE( + "Timed out dequeuing for buffer. Timeout set to " + + std::to_string(timeout_.count()) + " ms"); + } + return buffer; + } + + // Returns estimated number of buffers in the pool + size_t size() { + return bufferQueue_.size(); + } + + private: + static const uint64_t kMinChunkSize = 1LL << 20; + const uint64_t defaultInitialChunkSize_ = kMinChunkSize; + const std::chrono::milliseconds timeout_ = std::chrono::milliseconds(1000); + + std::shared_ptr executor_; + folly::DMPMCQueue bufferQueue_; + MemoryPool& memoryPool_; + + BufferPtr newBuffer() { + return std::make_unique(memoryPool_, defaultInitialChunkSize_); + } + + // clears all buffers in the pool + void deleteBufferPool() { + while (!bufferQueue_.empty()) { + BufferPtr buffer; + bufferQueue_.dequeue(buffer); + buffer.reset(); + } + } }; } // namespace facebook::nimble diff --git a/dwio/nimble/common/tests/BufferPoolTests.cpp b/dwio/nimble/common/tests/BufferPoolTests.cpp new file mode 100644 index 0000000..18dab0c --- /dev/null +++ b/dwio/nimble/common/tests/BufferPoolTests.cpp @@ -0,0 +1,178 @@ +/* + * Copyright (c) Meta Platforms, Inc. and its affiliates. + * + * Licensed 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 +#include "dwio/nimble/common/Buffer.h" +#include "dwio/nimble/common/Exceptions.h" +#include "folly/executors/CPUThreadPoolExecutor.h" +#include "velox/common/memory/Memory.h" +#include "velox/dwio/common/ExecutorBarrier.h" + +namespace facebook::nimble::test { +using MemoryPool = velox::memory::MemoryPool; +using ExecutorBarrier = velox::dwio::common::ExecutorBarrier; + +class BufferPoolTest : public ::testing::Test { + protected: + static void SetUpTestCase() {} + + void SetUp() override { + memPool_ = velox::memory::deprecatedAddDefaultLeafMemoryPool(); + } + + std::shared_ptr memPool_; +}; + +TEST_F(BufferPoolTest, CreateBufferPool) { + auto bufferPool = BufferPool{*memPool_}; + EXPECT_NO_THROW(bufferPool); +} + +TEST_F(BufferPoolTest, CreateBufferPoolWithInitialSize) { + auto bufferPool = + BufferPool{*memPool_, std::chrono::milliseconds{10}, 10, 10}; + EXPECT_EQ(bufferPool.size(), 10); +} + +TEST_F(BufferPoolTest, CreateBufferPoolBadTimeout) { + auto throwLambda = [&]() { + auto bufferPool = BufferPool{*memPool_, std::chrono::milliseconds{0}}; + }; + EXPECT_THROW(throwLambda(), NimbleUserError); + + try { + throwLambda(); + } catch (const NimbleUserError& e) { + EXPECT_EQ(e.errorMessage(), "timeout must be > 0"); + } +} + +TEST_F(BufferPoolTest, CreateBufferPoolBadMaxPool) { + auto throwLambda = [&]() { + auto bufferPool = BufferPool{*memPool_, std::chrono::milliseconds{1}, 0}; + }; + EXPECT_THROW(throwLambda(), NimbleUserError); + + try { + throwLambda(); + } catch (const NimbleUserError& e) { + EXPECT_EQ(e.errorMessage(), "max pool size must be > 0"); + } +} + +TEST_F(BufferPoolTest, CreateBufferPoolBadInitialSizeMaxSize) { + auto throwLambda = [&]() { + auto bufferPool = BufferPool{*memPool_, std::chrono::milliseconds{1}, 1, 2}; + }; + EXPECT_THROW(throwLambda(), NimbleUserError); + + try { + throwLambda(); + } catch (const NimbleUserError& e) { + EXPECT_EQ(e.errorMessage(), "initial pool size must be <= max pool size"); + } +} + +TEST_F(BufferPoolTest, ReserveBuffer) { + auto bufferPool = BufferPool{*memPool_}; + auto buffer = bufferPool.reserveBuffer(); + EXPECT_NE(buffer, nullptr); +} + +TEST_F(BufferPoolTest, AddBuffer) { + auto bufferPool = BufferPool{*memPool_}; + auto buffer = bufferPool.reserveBuffer(); + EXPECT_NE(buffer, nullptr); + EXPECT_EQ(bufferPool.size(), 0); + bufferPool.addBuffer(std::move(buffer)); + EXPECT_EQ(bufferPool.size(), 1); +} + +TEST_F(BufferPoolTest, DestroyBufferPool) { + auto bufferPoolPtr = std::make_unique(*memPool_); + bufferPoolPtr.reset(); + EXPECT_NO_THROW(); +} + +TEST_F(BufferPoolTest, emptyBufferPool) { + auto bufferPool = BufferPool{*memPool_, std::chrono::milliseconds{10}, 1}; + EXPECT_EQ(bufferPool.size(), 1); + + auto buffer1 = bufferPool.reserveBuffer(); + EXPECT_EQ(bufferPool.size(), 0); +} + +TEST_F(BufferPoolTest, OverfillBufferPool) { + auto bufferPool = BufferPool{*memPool_, std::chrono::milliseconds{10}, 1}; + auto throwLambda = [&]() { + for (auto i = 0; i < 10; i++) { + auto buffer = std::make_unique(*memPool_); + bufferPool.addBuffer(std::move(buffer)); + } + }; + + EXPECT_NO_THROW(throwLambda()); + EXPECT_GE(bufferPool.size(), 1); +} + +TEST_F(BufferPoolTest, FillEmptyFillBufferPool) { + size_t iterations = 10; + std::vector buffers; + + auto bufferPool = + BufferPool{*memPool_, std::chrono::milliseconds{10}, iterations}; + for (auto i = 0; i < iterations; i++) { + auto buffer = bufferPool.reserveBuffer(); + buffers.push_back(std::move(buffer)); + } + EXPECT_EQ(bufferPool.size(), 0); + EXPECT_EQ(buffers.size(), iterations); + for (auto& buffer : buffers) { + bufferPool.addBuffer(std::move(buffer)); + } + EXPECT_EQ(bufferPool.size(), iterations); + buffers.clear(); + + for (auto i = 0; i < iterations; i++) { + auto buffer = bufferPool.reserveBuffer(); + buffers.push_back(std::move(buffer)); + } + EXPECT_EQ(bufferPool.size(), 0); + EXPECT_EQ(buffers.size(), iterations); +} + +TEST_F(BufferPoolTest, ParallelFillPool) { + folly::CPUThreadPoolExecutor executor{10}; + ExecutorBarrier barrier{executor}; + auto bufferPool = + BufferPool{*memPool_, std::chrono::milliseconds{1000 * 10}, 100}; + auto fillPool = [&]() { + for (auto i = 0; i < 10; i++) { + EXPECT_NO_THROW( + auto buffer = bufferPool.reserveBuffer(); + std::this_thread::sleep_for(std::chrono::milliseconds{1000}); + bufferPool.addBuffer(std::move(buffer));); + } + }; + + for (auto i = 0; i < 10; i++) { + barrier.add(fillPool); + } + + barrier.waitAll(); +} + +} // namespace facebook::nimble::test diff --git a/dwio/nimble/velox/FieldWriter.cpp b/dwio/nimble/velox/FieldWriter.cpp index 3761991..e05cb61 100644 --- a/dwio/nimble/velox/FieldWriter.cpp +++ b/dwio/nimble/velox/FieldWriter.cpp @@ -288,7 +288,6 @@ class SimpleFieldWriter : public FieldWriter { void write(const velox::VectorPtr& vector, const OrderedRanges& ranges) override { auto size = ranges.size(); - auto& buffer = context_.stringBuffer(); auto& data = valuesStream_.mutableData(); if (auto flat = vector->asFlatVector()) { @@ -330,8 +329,11 @@ class SimpleFieldWriter : public FieldWriter { valuesStream_.mutableNonNulls(), Flat{vector}, [&](SourceType value) { + auto bufferPtr = context_.bufferPool().reserveBuffer(); + auto& buffer = *bufferPtr; data.push_back( C::convert(value, buffer, valuesStream_.extraMemory())); + context_.bufferPool().addBuffer(std::move(bufferPtr)); }); } } else { @@ -343,8 +345,11 @@ class SimpleFieldWriter : public FieldWriter { valuesStream_.mutableNonNulls(), Decoded{decoded}, [&](SourceType value) { + auto bufferPtr = context_.bufferPool().reserveBuffer(); + auto& buffer = *bufferPtr; data.push_back( C::convert(value, buffer, valuesStream_.extraMemory())); + context_.bufferPool().addBuffer(std::move(bufferPtr)); }); context_.decodingPairPool().addPair(std::move(pair)); } diff --git a/dwio/nimble/velox/FieldWriter.h b/dwio/nimble/velox/FieldWriter.h index 1cbbf97..c6c08e8 100644 --- a/dwio/nimble/velox/FieldWriter.h +++ b/dwio/nimble/velox/FieldWriter.h @@ -125,7 +125,8 @@ struct FieldWriterContext { std::unique_ptr reclaimer = nullptr, std::function vectorDecoderVisitor = []() {}, std::chrono::milliseconds timeout = std::chrono::milliseconds(1000 * 10), - size_t maxPoolSize = std::thread::hardware_concurrency()) + size_t maxPoolSize = std::thread::hardware_concurrency(), + size_t initialBufferCount = 10) : bufferMemoryPool{memoryPool.addLeafChild( "field_writer_buffer", true, @@ -133,12 +134,15 @@ struct FieldWriterContext { writeExecutor{std::move(writeExecutor)}, inputBufferGrowthPolicy{ DefaultInputBufferGrowthPolicy::withDefaultRanges()}, + bufferPool_{std::make_unique( + *bufferMemoryPool, + timeout, + maxPoolSize, + initialBufferCount)}, decodingPairPool_{std::make_unique( std::move(vectorDecoderVisitor), timeout, - maxPoolSize)} { - resetStringBuffer(); - } + maxPoolSize)} {} std::shared_ptr bufferMemoryPool; std::shared_ptr writeExecutor; @@ -161,13 +165,8 @@ struct FieldWriterContext { return *decodingPairPool_; } - Buffer& stringBuffer() { - return *buffer_; - } - - // Reset writer context for use by next stripe. - void resetStringBuffer() { - buffer_ = std::make_unique(*bufferMemoryPool); + BufferPool& bufferPool() { + return *bufferPool_; } const std::vector>& streams() { @@ -197,7 +196,7 @@ struct FieldWriterContext { } private: - std::unique_ptr buffer_; + std::unique_ptr bufferPool_; std::unique_ptr decodingPairPool_; std::vector> streams_; }; diff --git a/dwio/nimble/velox/VeloxWriter.cpp b/dwio/nimble/velox/VeloxWriter.cpp index ff926da..56cbae7 100644 --- a/dwio/nimble/velox/VeloxWriter.cpp +++ b/dwio/nimble/velox/VeloxWriter.cpp @@ -70,7 +70,8 @@ class WriterContext : public FieldWriterContext { options.reclaimerFactory(), options.vectorDecoderVisitor, options.poolTimeout, - options.maxPoolSize + options.maxPoolSize, + options.initialBufferCount }, options{std::move(options)}, logger{this->options.metricsLogger} { @@ -622,9 +623,6 @@ void VeloxWriter::writeChunk(bool lastChunk) { LoggingScope scope{*context_->logger}; velox::CpuWallTimer veloxTimer{context_->stripeFlushTiming}; - if (!encodingBuffer_) { - encodingBuffer_ = std::make_unique(*encodingMemoryPool_); - } streams_.resize(context_->schemaBuilder.nodeCount()); // When writing null streams, we write the nulls as data, and the stream @@ -668,9 +666,11 @@ void VeloxWriter::writeChunk(bool lastChunk) { auto encode = [&](StreamData& streamData) { const auto offset = streamData.descriptor().offset(); - auto encoded = encodeStream(*context_, *encodingBuffer_, streamData); + auto bufferPtr = context_->bufferPool().reserveBuffer(); + auto& buffer = *bufferPtr; + auto encoded = encodeStream(*context_, buffer, streamData); if (!encoded.empty()) { - ChunkedStreamWriter chunkWriter{*encodingBuffer_}; + ChunkedStreamWriter chunkWriter{buffer}; NIMBLE_DASSERT(offset < streams_.size(), "Stream offset out of range."); auto& stream = streams_[offset]; for (auto& buffer : chunkWriter.encode(encoded)) { @@ -679,6 +679,8 @@ void VeloxWriter::writeChunk(bool lastChunk) { } } streamData.reset(); + + context_->bufferPool().addBuffer(std::move(bufferPtr)); }; auto processStream = [&](StreamData& streamData, @@ -782,10 +784,6 @@ uint32_t VeloxWriter::writeStripe() { uint64_t startSize = writer_.size(); writer_.writeStripe(context_->rowsInStripe, std::move(streams_)); stripeSize = writer_.size() - startSize; - encodingBuffer_.reset(); - // TODO: once chunked string fields are supported, move string buffer - // reset to writeChunk() - context_->resetStringBuffer(); } NIMBLE_ASSERT( diff --git a/dwio/nimble/velox/VeloxWriter.h b/dwio/nimble/velox/VeloxWriter.h index adb1e5b..d67b2ca 100644 --- a/dwio/nimble/velox/VeloxWriter.h +++ b/dwio/nimble/velox/VeloxWriter.h @@ -77,7 +77,6 @@ class VeloxWriter { TabletWriter writer_; std::unique_ptr root_; - std::unique_ptr encodingBuffer_; std::vector streams_; std::exception_ptr lastException_; const velox::common::SpillConfig* const spillConfig_; diff --git a/dwio/nimble/velox/VeloxWriterOptions.h b/dwio/nimble/velox/VeloxWriterOptions.h index d5bac31..bacde5d 100644 --- a/dwio/nimble/velox/VeloxWriterOptions.h +++ b/dwio/nimble/velox/VeloxWriterOptions.h @@ -128,7 +128,7 @@ struct VeloxWriterOptions { std::chrono::milliseconds poolTimeout = std::chrono::milliseconds{1000 * 10}; size_t maxPoolSize = std::thread::hardware_concurrency(); - + size_t initialBufferCount = 20; // should be enough for 1 stripe // If provided, internal encoding operations will happen in parallel using // this executor. std::shared_ptr encodingExecutor; diff --git a/dwio/nimble/velox/tests/VeloxWriterTests.cpp b/dwio/nimble/velox/tests/VeloxWriterTests.cpp index a39830e..4f3dc74 100644 --- a/dwio/nimble/velox/tests/VeloxWriterTests.cpp +++ b/dwio/nimble/velox/tests/VeloxWriterTests.cpp @@ -321,11 +321,15 @@ TEST_F(VeloxWriterTests, MemoryReclaimPath) { std::string file; auto writeFile = std::make_unique(&file); std::atomic_bool reclaimEntered = false; - nimble::VeloxWriterOptions writerOptions{.reclaimerFactory = [&]() { - auto reclaimer = std::make_unique(); - reclaimer->setEnterArbitrationFunc([&]() { reclaimEntered = true; }); - return reclaimer; - }}; + nimble::VeloxWriterOptions writerOptions{ + .reclaimerFactory = + [&]() { + auto reclaimer = std::make_unique(); + reclaimer->setEnterArbitrationFunc( + [&]() { reclaimEntered = true; }); + return reclaimer; + }, + .initialBufferCount = 2}; nimble::VeloxWriter writer( *writerPool, type, std::move(writeFile), std::move(writerOptions)); auto batches = generateBatches(type, 100, 4000, 20221110, *leafPool_);