57 lines
1.4 KiB
C++
57 lines
1.4 KiB
C++
/*
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* This file is open source software, licensed to you under the terms
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* of the Apache License, Version 2.0 (the "License"). See the NOTICE file
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* distributed with this work for additional information regarding copyright
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* ownership. You may not use this file except in compliance with the License.
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*
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* You may obtain a copy of the License at
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*
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* http://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,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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*/
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/*
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* Copyright (C) 2015 Cloudius Systems, Ltd.
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*/
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#ifndef CORE_RWLOCK_HH_
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#define CORE_RWLOCK_HH_
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#include "semaphore.hh"
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class rwlock {
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static const size_t max_ops = std::numeric_limits<size_t>::max();
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semaphore _sem;
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public:
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rwlock()
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: _sem(max_ops) {
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}
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future<> read_lock() {
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return _sem.wait();
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}
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void read_unlock() {
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_sem.signal();
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}
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future<> write_lock() {
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return _sem.wait(max_ops);
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}
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void write_unlock() {
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_sem.signal(max_ops);
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}
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bool try_read_lock() {
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return _sem.try_wait();
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}
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bool try_write_lock() {
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return _sem.try_wait(max_ops);
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}
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};
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#endif /* CORE_RWLOCK_HH_ */
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