Files
OpenSpace/modules/globebrowsing/other/lruthreadpool.h
Alexander Bock 0e9edaeb12 Fix byte order mark commits
Update Ghoul
2017-07-17 15:54:00 -04:00

99 lines
4.3 KiB
C++

/*****************************************************************************************
* *
* OpenSpace *
* *
* Copyright (c) 2014-2017 *
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy of this *
* software and associated documentation files (the "Software"), to deal in the Software *
* without restriction, including without limitation the rights to use, copy, modify, *
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to *
* permit persons to whom the Software is furnished to do so, subject to the following *
* conditions: *
* *
* The above copyright notice and this permission notice shall be included in all copies *
* or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, *
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A *
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT *
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF *
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE *
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
****************************************************************************************/
#ifndef __OPENSPACE_MODULE_GLOBEBROWSING___LRU_THREAD_POOL___H__
#define __OPENSPACE_MODULE_GLOBEBROWSING___LRU_THREAD_POOL___H__
#include <modules/globebrowsing/cache/lrucache.h>
#include <condition_variable>
#include <functional>
#include <mutex>
#include <queue>
#include <thread>
#include <vector>
#include <atomic>
// Implementatin based on http://progsch.net/wordpress/?p=81
namespace openspace::globebrowsing {
template<typename KeyType> class LRUThreadPool;
template<typename KeyType>
class LRUThreadPoolWorker {
public:
LRUThreadPoolWorker(LRUThreadPool<KeyType>& pool);
void operator()();
private:
LRUThreadPool<KeyType>& _pool;
};
/**
* The <code>LRUThreadPool</code> will only enqueue a certain number of tasks. The most
* recently enqueued task is the one that will be executed first. This class is templated
* on a key type which used as an identifier to determine wheter or not a task with the
* given key has been enqueued or not. This means that a task can be enqueued several
* times. The user must ensure that an enqueued task with a given key should be
* equal in outcome to a second enqueued task with the same key. This is because a second
* enqueued task with the same key will simply be bumped and prioritised before other
* enqueued tasks. The given task will be ignored.
*/
template<typename KeyType>
class LRUThreadPool {
public:
LRUThreadPool(size_t numThreads, size_t queueSize);
LRUThreadPool(const LRUThreadPool& toCopy);
~LRUThreadPool();
void enqueue(std::function<void()> f, KeyType key);
bool touch(KeyType key);
std::vector<KeyType> getQueuedTasksKeys();
std::vector<KeyType> getUnqueuedTasksKeys();
void clearEnqueuedTasks();
private:
struct DefaultHasher {
unsigned long long operator()(const KeyType& key) const {
return static_cast<unsigned long long>(key);
}
};
friend class LRUThreadPoolWorker<KeyType>;
std::vector<std::thread> _workers;
cache::LRUCache<KeyType, std::function<void()>, DefaultHasher> _queuedTasks;
std::vector<KeyType> _unqueuedTasks;
std::mutex _queueMutex;
std::condition_variable _condition;
bool _stop;
};
} // namespace openspace::globebrowsing
#include "lruthreadpool.inl"
#endif // __OPENSPACE_MODULE_GLOBEBROWSING___LRU_THREAD_POOL___H__