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/* SPDX-License-Identifier: Apache-2.0
* Copyright 2011-2022 Blender Foundation */
#ifndef __UTIL_SEMAPHORE_H__
#define __UTIL_SEMAPHORE_H__
#include "util/thread.h"
CCL_NAMESPACE_BEGIN
/* Counting Semaphore
*
* To restrict concurrent access to a resource to a specified number
* of threads. Similar to std::counting_semaphore from C++20. */
class thread_counting_semaphore {
public:
explicit thread_counting_semaphore(const int count) : count(count)
{
}
thread_counting_semaphore(const thread_counting_semaphore &) = delete;
void acquire()
{
thread_scoped_lock lock(mutex);
while (count == 0) {
condition.wait(lock);
}
count--;
}
void release()
{
thread_scoped_lock lock(mutex);
count++;
condition.notify_one();
}
protected:
thread_mutex mutex;
thread_condition_variable condition;
int count;
};
CCL_NAMESPACE_END
#endif /* __UTIL_SEMAPHORE_H__ */
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