Summary: Red diff to remove existing implementation of garbage collection. The current approach is reference counting kind of approach and require a lot of effort to get the size counter right on compaction and deletion. I'm going to go with a simple mark-sweep kind of approach and will send another PR for that. CompactionEventListener was added solely for blob db and it adds complexity and overhead to compaction iterator. Removing it as well. Closes https://github.com/facebook/rocksdb/pull/3551 Differential Revision: D7130190 Pulled By: yiwu-arbug fbshipit-source-id: c3a375ad2639a3f6ed179df6eda602372cc5b8dfmain
Yi Wu
7 years ago
committed by
Facebook Github Bot
parent
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// Portions Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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// Large parts of this file is borrowed from the public domain code below.
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// from https://github.com/mstump/queues
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// C++ implementation of Dmitry Vyukov's non-intrusive
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// lock free unbound MPSC queue
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// http://www.1024cores.net/home/
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// lock-free-algorithms/queues/non-intrusive-mpsc-node-based-queue
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// License from mstump/queues
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// This is free and unencumbered software released into the public domain.
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//
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// Anyone is free to copy, modify, publish, use, compile, sell, or
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// distribute this software, either in source code form or as a compiled
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// binary, for any purpose, commercial or non-commercial, and by any
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// means.
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//
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// In jurisdictions that recognize copyright laws, the author or authors
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// of this software dedicate any and all copyright interest in the
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// software to the public domain. We make this dedication for the benefit
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// of the public at large and to the detriment of our heirs and
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// successors. We intend this dedication to be an overt act of
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// relinquishment in perpetuity of all present and future rights to this
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// software under copyright law.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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// IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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// OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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// OTHER DEALINGS IN THE SOFTWARE.
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//
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// For more information, please refer to <http://unlicense.org>
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// License from http://www.1024cores.net/home/
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// lock-free-algorithms/queues/non-intrusive-mpsc-node-based-queue
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// Copyright (c) 2010-2011 Dmitry Vyukov. All rights reserved.
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// Redistribution and use in source and binary forms, with or
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// without modification, are permitted provided that the following
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// conditions are met:
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// 1. Redistributions of source code must retain the above copyright notice,
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// this list of conditions and the following disclaimer.
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//
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// 2. Redistributions in binary form must reproduce the above copyright notice,
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// this list of conditions and the following disclaimer in the documentation
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// and/or other materials provided with the distribution.
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//
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// THIS SOFTWARE IS PROVIDED BY DMITRY VYUKOV "AS IS" AND ANY EXPRESS OR
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// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
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// EVENT SHALL DMITRY VYUKOV OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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// USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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// The views and conclusions contained in the software and documentation
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// are those of the authors and should not be interpreted as representing
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// official policies, either expressed or implied, of Dmitry Vyukov.
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//
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#ifndef UTIL_MPSC_H_ |
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#define UTIL_MPSC_H_ |
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#include <atomic> |
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#include <cassert> |
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#include <type_traits> |
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/**
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* Multiple Producer Single Consumer Lockless Q |
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*/ |
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template <typename T> |
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class mpsc_queue_t { |
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public: |
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struct buffer_node_t { |
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T data; |
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std::atomic<buffer_node_t*> next; |
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}; |
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mpsc_queue_t() { |
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buffer_node_aligned_t* al_st = new buffer_node_aligned_t; |
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buffer_node_t* node = new (al_st) buffer_node_t(); |
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_head.store(node); |
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_tail.store(node); |
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node->next.store(nullptr, std::memory_order_relaxed); |
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} |
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~mpsc_queue_t() { |
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T output; |
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while (this->dequeue(&output)) { |
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} |
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buffer_node_t* front = _head.load(std::memory_order_relaxed); |
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front->~buffer_node_t(); |
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::operator delete(front); |
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} |
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void enqueue(const T& input) { |
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buffer_node_aligned_t* al_st = new buffer_node_aligned_t; |
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buffer_node_t* node = new (al_st) buffer_node_t(); |
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node->data = input; |
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node->next.store(nullptr, std::memory_order_relaxed); |
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buffer_node_t* prev_head = _head.exchange(node, std::memory_order_acq_rel); |
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prev_head->next.store(node, std::memory_order_release); |
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} |
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bool dequeue(T* output) { |
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buffer_node_t* tail = _tail.load(std::memory_order_relaxed); |
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buffer_node_t* next = tail->next.load(std::memory_order_acquire); |
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if (next == nullptr) { |
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return false; |
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} |
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*output = next->data; |
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_tail.store(next, std::memory_order_release); |
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tail->~buffer_node_t(); |
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::operator delete(tail); |
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return true; |
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} |
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// you can only use pop_all if the queue is SPSC
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buffer_node_t* pop_all() { |
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// nobody else can move the tail pointer.
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buffer_node_t* tptr = _tail.load(std::memory_order_relaxed); |
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buffer_node_t* next = |
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tptr->next.exchange(nullptr, std::memory_order_acquire); |
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_head.exchange(tptr, std::memory_order_acquire); |
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// there is a race condition here
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return next; |
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} |
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private: |
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typedef typename std::aligned_storage< |
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sizeof(buffer_node_t), std::alignment_of<buffer_node_t>::value>::type |
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buffer_node_aligned_t; |
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std::atomic<buffer_node_t*> _head; |
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std::atomic<buffer_node_t*> _tail; |
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mpsc_queue_t(const mpsc_queue_t&) = delete; |
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mpsc_queue_t& operator=(const mpsc_queue_t&) = delete; |
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}; |
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#endif // UTIL_MPSC_H_
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