Gaudi::Utils::PeriodicAction Class Reference

Helper to periodically run asynchronous tasks. More...

#include </builds/gaudi/Gaudi/GaudiUtils/include/Gaudi/Utils/PeriodicAction.h>

Collaboration diagram for Gaudi::Utils::PeriodicAction:

Public Types
using	clock = std::chrono::steady_clock
using	time_point = clock::time_point
using	callback_t = std::function<void()>

Public Member Functions
	PeriodicAction (callback_t callback, std::chrono::milliseconds period_duration, bool autostart=true, unsigned int repetitions=0)
	PeriodicAction (PeriodicAction &&)=default
PeriodicAction &	operator= (PeriodicAction &&)=default
	~PeriodicAction ()
void	start ()
void	stop ()

Private Attributes
std::thread	m_thread
std::promise< void >	m_stop_thread
callback_t	m_callback
std::chrono::milliseconds	m_period_duration
unsigned int	m_repetitions

Detailed Description

Helper to periodically run asynchronous tasks.

An instance of this starts a dedicated thread that periodically runs the user specified callback.

The thread starts as soon as the instance is created and it's automatically terminated (and joined) on destruction. It's also possible to defer the start (if requested at construction time), anticipate the stop and specify a maximum number of repetitions (if >0).

Definition at line 29 of file PeriodicAction.h.

Member Typedef Documentation

callback_t

using Gaudi::Utils::PeriodicAction::callback_t = std::function<void()>

Definition at line 33 of file PeriodicAction.h.

clock

using Gaudi::Utils::PeriodicAction::clock = std::chrono::steady_clock

Definition at line 31 of file PeriodicAction.h.

time_point

using Gaudi::Utils::PeriodicAction::time_point = clock::time_point

Definition at line 32 of file PeriodicAction.h.

Constructor & Destructor Documentation

PeriodicAction() [1/2]

PeriodicAction::PeriodicAction	(	callback_t	callback,
		std::chrono::milliseconds	period_duration,
		bool	autostart = true,
		unsigned int	repetitions = 0 )

Definition at line 16 of file PeriodicAction.cpp.

    : m_callback{ std::move( callback ) }, m_period_duration{ period_duration }, m_repetitions{ repetitions } {
  if ( autostart ) start();
}

PeriodicAction() [2/2]

Gaudi::Utils::PeriodicAction::PeriodicAction ( PeriodicAction && )

default

~PeriodicAction()

PeriodicAction::~PeriodicAction

(

)

Definition at line 22 of file PeriodicAction.cpp.

{ stop(); }

Member Function Documentation

operator=()

PeriodicAction & Gaudi::Utils::PeriodicAction::operator= ( PeriodicAction && )

default

start()

void PeriodicAction::start

(

)

Definition at line 24 of file PeriodicAction.cpp.

                           {
  if ( !m_thread.joinable() && m_period_duration.count() > 0 ) {
    // Note: we can move the callback because we are not going to use it
    // outside of the thread
    m_thread = std::thread{ [period_duration = m_period_duration, callback = std::move( m_callback ),
                             stop_signal = m_stop_thread.get_future(), repetitions = m_repetitions] {
      unsigned int n         = 0;
      auto         next_call = clock::now() + period_duration;
      while ( ( repetitions == 0 || n < repetitions ) &&
              stop_signal.wait_until( next_call ) == std::future_status::timeout ) {
        ++n;
        callback();
        // ensure the next call is at a multiple
        // of m_period_duration after the last one
        const auto now = clock::now();
        while ( next_call < now ) next_call += period_duration;
      }
    } };
  }
}

stop()

void PeriodicAction::stop

(

)

Definition at line 45 of file PeriodicAction.cpp.

                          {
  if ( m_thread.joinable() ) {
    m_stop_thread.set_value();
    m_thread.join();
  }
}

Member Data Documentation

m_callback

callback_t Gaudi::Utils::PeriodicAction::m_callback

private

Definition at line 48 of file PeriodicAction.h.

m_period_duration

std::chrono::milliseconds Gaudi::Utils::PeriodicAction::m_period_duration

private

Definition at line 49 of file PeriodicAction.h.

m_repetitions

unsigned int Gaudi::Utils::PeriodicAction::m_repetitions

private

Definition at line 50 of file PeriodicAction.h.

m_stop_thread

std::promise<void> Gaudi::Utils::PeriodicAction::m_stop_thread

private

Definition at line 47 of file PeriodicAction.h.

m_thread

std::thread Gaudi::Utils::PeriodicAction::m_thread

private

Definition at line 46 of file PeriodicAction.h.

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The documentation for this class was generated from the following files:

• GaudiUtils/include/Gaudi/Utils/PeriodicAction.h
• GaudiUtils/src/Lib/PeriodicAction.cpp