99b8a4f234
Summary: Skiplist ReverseIterator and Distance Approximation Test Plan: manual Reviewers: florijan, buda Reviewed By: buda Subscribers: pullbot, florijan, buda Differential Revision: https://phabricator.memgraph.io/D44
29 lines
692 B
C++
29 lines
692 B
C++
#pragma once
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#include <unistd.h>
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#include <atomic>
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#include "utils/cpu_relax.hpp"
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/**
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* @class SpinLock
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*
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* @brief
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* Spinlock is used as an locking mechanism based on an atomic flag and
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* waiting loops. It uses the cpu_relax "asm pause" command to optimize wasted
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* time while the threads are waiting.
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*
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*/
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class SpinLock {
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public:
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void lock() { // Before was memory_order_acquire
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while (lock_flag.test_and_set(std::memory_order_seq_cst)) cpu_relax();
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}
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// Before was memory_order_release
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void unlock() { lock_flag.clear(std::memory_order_seq_cst); }
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private:
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// guaranteed by standard to be lock free!
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mutable std::atomic_flag lock_flag = ATOMIC_FLAG_INIT;
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};
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