9cfc7967dd
* Replace license text in headers with SPDX identifiers. * Remove specific license info from outdated readme.txt, instead leave details to the source files. * Add list of SPDX license identifiers used, and corresponding license texts. * Update copyright dates while we're at it. Ref D14069, T95597
49 lines
926 B
C++
49 lines
926 B
C++
/* SPDX-License-Identifier: Apache-2.0
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* Copyright 2011-2022 Blender Foundation */
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#ifndef __UTIL_SEMAPHORE_H__
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#define __UTIL_SEMAPHORE_H__
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#include "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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