// Copyright CERN and copyright holders of ALICE O2. This software is

// distributed under the terms of the GNU General Public License v3 (GPL

// Version 3), copied verbatim in the file "COPYING".

//

// See http://alice-o2.web.cern.ch/license for full licensing information.

//

// In applying this license CERN does not waive the privileges and immunities

// granted to it by virtue of its status as an Intergovernmental Organization

// or submit itself to any jurisdiction.

//-*- Mode: C++ -*-

#ifndef HEARTBEATSAMPLER_H

#define HEARTBEATSAMPLER_H

// @file HeartbeatSampler.h

// @author Matthias Richter

// @since 2017-02-03

// @brief Heartbeat sampler device

#include "Headers/DataHeader.h"

#include "Headers/HeartbeatFrame.h"

#include "O2Device/O2Device.h"

#include <string>

namespace o2

{

namespace data_flow

{

/// @class HeartbeatSampler

/// @brief A sampler for heartbeat triggers

///

/// The device is going to be used in an emulation of the reader

/// processes on the FLP

/// The heartbeat triggers are sent out with constant frequency, the

/// period in nano seconds can be configured by option --period

///

/// TODO: the class can evolve to a general clock sampler device with

/// configurable period, even randomly distributed

class HeartbeatSampler : public base::O2Device

{

public:

typedef o2::base::O2Message O2Message;

static constexpr const char* OptionKeyOutputChannelName = "out-chan-name";

static constexpr const char* OptionKeyPeriod = "period";

HeartbeatSampler() = default;

~HeartbeatSampler() final = default;

protected:

/// overloading the InitTask() method of FairMQDevice

void InitTask() final;

/// overloading ConditionalRun method of FairMQDevice

bool ConditionalRun() final;

private:

/// publishing period (configurable)

uint32_t mPeriod = 1000000000;

/// name of the (configurable)

std::string mOutputChannelName = "output";

/// number of elapsed periods

int mCount = 0;

};

} // namespace data_flow

}; // namespace o2

#endif