// 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.

/// @file test_Fifo.cxx

/// @author Matthias Richter

/// @since 2016-12-06

/// @brief Test program for thread safe FIFO

#define BOOST_TEST_MODULE Utility test

#define BOOST_TEST_MAIN

#define BOOST_TEST_DYN_LINK

#include <boost/test/unit_test.hpp>

#include "Fifo.h"

#include <iostream>

#include <iomanip>

#include <unistd.h>

#include <thread>

const int nEvents = 6;

const int sleepTime = 1;

template <typename T>

bool processValue(T value)

{

std::cout << "processing " << value << std::endl;

sleep(sleepTime);

return (value + 1 < nEvents);

}

template <class FifoT, typename T>

void pushFifo(FifoT& fifo, T value = FifoT::value_type)

{

std::cout << "pushing " << value << std::endl;

fifo.push(value);

}

BOOST_AUTO_TEST_CASE(test_Fifo)

{

using value_type = unsigned int;

o2::test::Fifo<value_type> fifo;

// start a consumer thread which pulls from the FIFO to the function

// processValue with a simulated prcessing of one second.

std::thread consumer([&fifo]() {

do {

} while (fifo.pull([](value_type v) { return processValue(v); }));

});

// fill some values into the FIFO which the consumer can process

// immediately

unsigned int value = 0;

pushFifo(fifo, value++);

pushFifo(fifo, value++);

pushFifo(fifo, value++);

// now continue filling with a period longer than the consumer

// processing, consumer and producer are in sync once consumer

// has processed events which have been added to the FIFO before

while (value < nEvents) {

sleep(2 * sleepTime);

pushFifo(fifo, value++);

}

consumer.join();

}