icinga2/lib/base/timer.cpp

287 lines
6.6 KiB
C++

/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012-2014 Icinga Development Team (http://www.icinga.org) *
* *
* 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/utility.hpp"
#include <boost/bind.hpp>
#include <boost/foreach.hpp>
#include <boost/thread/thread.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>
using namespace icinga;
typedef boost::multi_index_container<
Timer::Holder,
boost::multi_index::indexed_by<
boost::multi_index::ordered_unique<boost::multi_index::const_mem_fun<Timer::Holder, Timer *, &Timer::Holder::GetObject> >,
boost::multi_index::ordered_non_unique<boost::multi_index::const_mem_fun<Timer::Holder, double, &Timer::Holder::GetNextUnlocked> >
>
> TimerSet;
static boost::mutex l_Mutex;
static boost::condition_variable l_CV;
static boost::thread l_Thread;
static bool l_StopThread;
static TimerSet l_Timers;
/**
* Constructor for the Timer class.
*/
Timer::Timer(void)
: m_Interval(0), m_Next(0)
{ }
/**
* Destructor for the Timer class.
*/
Timer::~Timer(void)
{
Stop();
}
/**
* Initializes the timer sub-system.
*/
void Timer::Initialize(void)
{
boost::mutex::scoped_lock lock(l_Mutex);
l_StopThread = false;
l_Thread = boost::thread(&Timer::TimerThreadProc);
}
/**
* Disables the timer sub-system.
*/
void Timer::Uninitialize(void)
{
{
boost::mutex::scoped_lock lock(l_Mutex);
l_StopThread = true;
l_CV.notify_all();
}
l_Thread.join();
}
/**
* Calls this timer.
*/
void Timer::Call(void)
{
ASSERT(!OwnsLock());
Timer::Ptr self = GetSelf();
try {
OnTimerExpired(self);
} catch (...) {
Reschedule();
throw;
}
Reschedule();
}
/**
* Sets the interval for this timer.
*
* @param interval The new interval.
*/
void Timer::SetInterval(double interval)
{
ASSERT(!OwnsLock());
boost::mutex::scoped_lock lock(l_Mutex);
m_Interval = interval;
}
/**
* Retrieves the interval for this timer.
*
* @returns The interval.
*/
double Timer::GetInterval(void) const
{
ASSERT(!OwnsLock());
boost::mutex::scoped_lock lock(l_Mutex);
return m_Interval;
}
/**
* Registers the timer and starts processing events for it.
*/
void Timer::Start(void)
{
ASSERT(!OwnsLock());
{
boost::mutex::scoped_lock lock(l_Mutex);
m_Started = true;
}
Reschedule();
}
/**
* Unregisters the timer and stops processing events for it.
*/
void Timer::Stop(void)
{
ASSERT(!OwnsLock());
boost::mutex::scoped_lock lock(l_Mutex);
m_Started = false;
l_Timers.erase(this);
/* Notify the worker thread that we've disabled a timer. */
l_CV.notify_all();
}
/**
* Reschedules this timer.
*
* @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::Reschedule(double next)
{
ASSERT(!OwnsLock());
boost::mutex::scoped_lock lock(l_Mutex);
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) {
/* 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_CV.notify_all();
}
}
/**
* Retrieves when the timer is next due.
*
* @returns The timestamp.
*/
double Timer::GetNext(void) const
{
ASSERT(!OwnsLock());
boost::mutex::scoped_lock lock(l_Mutex);
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_Mutex);
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;
BOOST_FOREACH(Timer *timer, idx) {
if (abs(now - (timer->m_Next + adjustment)) <
abs(now - timer->m_Next)) {
timer->m_Next += adjustment;
timers.push_back(timer);
}
}
BOOST_FOREACH(Timer *timer, timers) {
l_Timers.erase(timer);
l_Timers.insert(timer);
}
/* Notify the worker that we've rescheduled some timers. */
l_CV.notify_all();
}
/**
* Worker thread proc for Timer objects.
*/
void Timer::TimerThreadProc(void)
{
Utility::SetThreadName("Timer Thread");
for (;;) {
boost::mutex::scoped_lock lock(l_Mutex);
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_StopThread)
l_CV.wait(lock);
if (l_StopThread)
break;
NextTimerView::iterator it = idx.begin();
Timer *timer = *it;
double wait = timer->m_Next - Utility::GetTime();
if (wait > 0.01) {
/* Wait for the next timer. */
l_CV.timed_wait(lock, boost::posix_time::milliseconds(wait * 1000));
continue;
}
/* Remove the timer from the list so it doesn't get called again
* until the current call is completed. */
l_Timers.erase(timer);
Timer::Ptr ptimer = timer->GetSelf();
lock.unlock();
/* Asynchronously call the timer. */
Utility::QueueAsyncCallback(boost::bind(&Timer::Call, ptimer));
}
}