forked from bartvdbraak/blender
62 lines
1.4 KiB
C
62 lines
1.4 KiB
C
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/*
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* Copyright 2011-2020 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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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, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef __UTIL_SEMAPHORE_H__
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#define __UTIL_SEMAPHORE_H__
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#include "util/util_thread.h"
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CCL_NAMESPACE_BEGIN
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/* Counting Semaphore
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*
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* To restrict concurrent access to a resource to a specified number
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* of threads. Similar to std::counting_semaphore from C++20. */
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class thread_counting_semaphore {
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public:
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explicit thread_counting_semaphore(const int count) : count(count)
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{
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}
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thread_counting_semaphore(const thread_counting_semaphore &) = delete;
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void acquire()
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{
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thread_scoped_lock lock(mutex);
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while (count == 0) {
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condition.wait(lock);
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}
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count--;
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}
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void release()
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{
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thread_scoped_lock lock(mutex);
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count++;
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condition.notify_one();
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}
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protected:
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thread_mutex mutex;
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thread_condition_variable condition;
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int count;
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};
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CCL_NAMESPACE_END
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#endif /* __UTIL_SEMAPHORE_H__ */
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