60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
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/*******************************************************************************
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* Copyright (c) 2015-2018 Skymind, Inc.
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*
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* This program and the accompanying materials are made available under the
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* terms of the Apache License, Version 2.0 which is available at
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* https://www.apache.org/licenses/LICENSE-2.0.
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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* SPDX-License-Identifier: Apache-2.0
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******************************************************************************/
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//
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// Created by raver on 8/29/2018.
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//
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#ifndef LIBND4J_READWRITELOCK_H
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#define LIBND4J_READWRITELOCK_H
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#include <atomic>
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#include <mutex>
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/**
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* This class provides PRIMITIVE read-write lock, and should NOT be used outside of GraphServer due to its inefficiency.
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* However, since GraphServer isn't supposed to have Reads/Writes ration even close to 1.0, it'll work just fine.
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*
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* Basic idea: write lock won't be obtained before all read requests served
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*/
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namespace nd4j {
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class SimpleReadWriteLock {
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private:
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std::atomic<unsigned long long int> _read_locks;
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std::atomic<unsigned long long int> _write_locks;
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std::mutex _mutex;
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public:
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explicit SimpleReadWriteLock();
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SimpleReadWriteLock(const SimpleReadWriteLock& other);
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~SimpleReadWriteLock() = default;
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// read lock
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void lockRead();
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void unlockRead();
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// write lock
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void lockWrite();
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void unlockWrite();
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SimpleReadWriteLock& operator= ( const SimpleReadWriteLock &other);
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};
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}
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#endif //DEV_TESTS_READWRITELOCK_H
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