/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012-2018 Icinga Development Team (https://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. *
******************************************************************************/
#include "base/timer.hpp"
#include "base/debug.hpp"
#include "base/logger.hpp"
#include "base/utility.hpp"
#include <boost/thread/mutex.hpp>
#include <boost/thread/condition_variable.hpp>
#include <boost/multi_index_container.hpp>
#include <boost/multi_index/ordered_index.hpp>
#include <boost/multi_index/key_extractors.hpp>
#include <thread>
using namespace icinga;
namespace icinga {
class TimerHolder {
public:
TimerHolder(Timer *timer)
: m_Timer(timer)
{ }
inline Timer *GetObject() const
{
return m_Timer;
}
inline double GetNextUnlocked() const
{
return m_Timer->m_Next;
}
operator Timer *() const
{
return m_Timer;
}
private:
Timer *m_Timer;
};
}
typedef boost::multi_index_container<
TimerHolder,
boost::multi_index::indexed_by<
boost::multi_index::ordered_unique<boost::multi_index::const_mem_fun<TimerHolder, Timer *, &TimerHolder::GetObject> >,
boost::multi_index::ordered_non_unique<boost::multi_index::const_mem_fun<TimerHolder, double, &TimerHolder::GetNextUnlocked> >
>
> TimerSet;
static boost::mutex l_TimerMutex;
static boost::condition_variable l_TimerCV;
static std::thread l_TimerThread;
static bool l_StopTimerThread;
static TimerSet l_Timers;
static int l_AliveTimers = 0;
/**
* Destructor for the Timer class.
*/
Timer::~Timer()
{
Stop(true);
}
void Timer::Initialize()
{
boost::mutex::scoped_lock lock(l_TimerMutex);
if (l_AliveTimers > 0) {
InitializeThread();
}
}
void Timer::Uninitialize()
{
boost::mutex::scoped_lock lock(l_TimerMutex);
if (l_AliveTimers > 0) {
UninitializeThread();
}
}
void Timer::InitializeThread()
{
l_StopTimerThread = false;
l_TimerThread = std::thread(&Timer::TimerThreadProc);
}
void Timer::UninitializeThread()
{
{
l_StopTimerThread = true;
l_TimerCV.notify_all();
}
l_TimerMutex.unlock();
if (l_TimerThread.joinable())
l_TimerThread.join();
l_TimerMutex.lock();
}
/**
* Calls this timer.
*/
void Timer::Call()
{
try {
OnTimerExpired(Timer::Ptr(this));
} catch (...) {
InternalReschedule(true);
throw;
}
InternalReschedule(true);
}
/**
* Sets the interval for this timer.
*
* @param interval The new interval.
*/
void Timer::SetInterval(double interval)
{
boost::mutex::scoped_lock lock(l_TimerMutex);
m_Interval = interval;
}
/**
* Retrieves the interval for this timer.
*
* @returns The interval.
*/
double Timer::GetInterval() const
{
boost::mutex::scoped_lock lock(l_TimerMutex);
return m_Interval;
}
/**
* Registers the timer and starts processing events for it.
*/
void Timer::Start()
{
{
boost::mutex::scoped_lock lock(l_TimerMutex);
m_Started = true;
if (++l_AliveTimers == 1) {
InitializeThread();
}
}
InternalReschedule(false);
}
/**
* Unregisters the timer and stops processing events for it.
*/
void Timer::Stop(bool wait)
{
if (l_StopTimerThread)
return;
boost::mutex::scoped_lock lock(l_TimerMutex);
if (m_Started && --l_AliveTimers == 0) {
UninitializeThread();
}
m_Started = false;
l_Timers.erase(this);
/* Notify the worker thread that we've disabled a timer. */
l_TimerCV.notify_all();
while (wait && m_Running)
l_TimerCV.wait(lock);
}
void Timer::Reschedule(double next)
{
InternalReschedule(false, next);
}
/**
* Reschedules this timer.
*
* @param completed Whether the timer has just completed its callback.
* @param next The time when this timer should be called again. Use -1 to let
* the timer figure out a suitable time based on the interval.
*/
void Timer::InternalReschedule(bool completed, double next)
{
boost::mutex::scoped_lock lock(l_TimerMutex);
if (completed)
m_Running = false;
if (next < 0) {
/* Don't schedule the next call if this is not a periodic timer. */
if (m_Interval <= 0)
return;
next = Utility::GetTime() + m_Interval;
}
m_Next = next;
if (m_Started && !m_Running) {
/* Remove and re-add the timer to update the index. */
l_Timers.erase(this);
l_Timers.insert(this);
/* Notify the worker that we've rescheduled a timer. */
l_TimerCV.notify_all();
}
}
/**
* Retrieves when the timer is next due.
*
* @returns The timestamp.
*/
double Timer::GetNext() const
{
boost::mutex::scoped_lock lock(l_TimerMutex);
return m_Next;
}
/**
* Adjusts all timers by adding the specified amount of time to their
* next scheduled timestamp.
*
* @param adjustment The adjustment.
*/
void Timer::AdjustTimers(double adjustment)
{
boost::mutex::scoped_lock lock(l_TimerMutex);
double now = Utility::GetTime();
typedef boost::multi_index::nth_index<TimerSet, 1>::type TimerView;
TimerView& idx = boost::get<1>(l_Timers);
std::vector<Timer *> timers;
for (Timer *timer : idx) {
if (std::fabs(now - (timer->m_Next + adjustment)) <
std::fabs(now - timer->m_Next)) {
timer->m_Next += adjustment;
timers.push_back(timer);
}
}
for (Timer *timer : timers) {
l_Timers.erase(timer);
l_Timers.insert(timer);
}
/* Notify the worker that we've rescheduled some timers. */
l_TimerCV.notify_all();
}
/**
* Worker thread proc for Timer objects.
*/
void Timer::TimerThreadProc()
{
Log(LogDebug, "Timer", "TimerThreadProc started.");
Utility::SetThreadName("Timer Thread");
for (;;) {
boost::mutex::scoped_lock lock(l_TimerMutex);
typedef boost::multi_index::nth_index<TimerSet, 1>::type NextTimerView;
NextTimerView& idx = boost::get<1>(l_Timers);
/* Wait until there is at least one timer. */
while (idx.empty() && !l_StopTimerThread)
l_TimerCV.wait(lock);
if (l_StopTimerThread)
break;
auto it = idx.begin();
Timer *timer = *it;
double wait = timer->m_Next - Utility::GetTime();
if (wait > 0.01) {
/* Wait for the next timer. */
l_TimerCV.timed_wait(lock, boost::posix_time::milliseconds(long(wait * 1000)));
continue;
}
Timer::Ptr ptimer = timer;
/* Remove the timer from the list so it doesn't get called again
* until the current call is completed. */
l_Timers.erase(timer);
timer->m_Running = true;
lock.unlock();
/* Asynchronously call the timer. */
Utility::QueueAsyncCallback(std::bind(&Timer::Call, ptimer));
}
}