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Diffstat (limited to 'intern/cycles/util/semaphore.h')
-rw-r--r-- | intern/cycles/util/semaphore.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/intern/cycles/util/semaphore.h b/intern/cycles/util/semaphore.h new file mode 100644 index 00000000000..8da8a232ba2 --- /dev/null +++ b/intern/cycles/util/semaphore.h @@ -0,0 +1,61 @@ +/* + * Copyright 2011-2020 Blender Foundation + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#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__ */ |