icinga2/lib/base/threadpool.hpp

133 lines
3.2 KiB
C++

/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012-2018 Icinga Development Team (https://www.icinga.com/) *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License *
* as published by the Free Software Foundation; either version 2 *
* of the License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the Free Software Foundation *
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. *
******************************************************************************/
#ifndef THREADPOOL_H
#define THREADPOOL_H
#include "base/i2-base.hpp"
#include <boost/thread/thread.hpp>
#include <boost/thread/mutex.hpp>
#include <boost/thread/condition_variable.hpp>
#include <deque>
#include <thread>
namespace icinga
{
#define QUEUECOUNT 4U
enum SchedulerPolicy
{
DefaultScheduler,
LowLatencyScheduler
};
/**
* A thread pool.
*
* @ingroup base
*/
class ThreadPool
{
public:
typedef std::function<void ()> WorkFunction;
ThreadPool(size_t max_threads = UINT_MAX);
~ThreadPool();
void Start();
void Stop();
bool Post(const WorkFunction& callback, SchedulerPolicy policy = DefaultScheduler);
private:
enum ThreadState
{
ThreadUnspecified,
ThreadDead,
ThreadIdle,
ThreadBusy
};
struct WorkItem
{
WorkFunction Callback;
double Timestamp;
};
struct Queue;
struct WorkerThread
{
ThreadState State{ThreadDead};
bool Zombie{false};
double Utilization{0};
double LastUpdate{0};
boost::thread *Thread{nullptr};
WorkerThread(ThreadState state = ThreadDead)
: State(state)
{ }
void UpdateUtilization(ThreadState state = ThreadUnspecified);
void ThreadProc(Queue& queue);
};
struct Queue
{
boost::mutex Mutex;
boost::condition_variable CV;
boost::condition_variable CVStarved;
std::deque<WorkItem> Items;
double WaitTime{0};
double ServiceTime{0};
int TaskCount{0};
bool Stopped{false};
WorkerThread Threads[16];
void SpawnWorker(boost::thread_group& group);
void KillWorker(boost::thread_group& group);
};
int m_ID;
static int m_NextID;
size_t m_MaxThreads;
boost::thread_group m_ThreadGroup;
std::thread m_MgmtThread;
boost::mutex m_MgmtMutex;
boost::condition_variable m_MgmtCV;
bool m_Stopped{true};
Queue m_Queues[QUEUECOUNT];
void ManagerThreadProc();
};
}
#endif /* EVENTQUEUE_H */