added basic setup

package main

import (

	"flag"

	"fmt"

	"os"

	"time"

	"repositories.muehmer.net/bsmrgo/stars/pkg/stars/simulator"

)

func main() {

	fmt.Fprintln(os.Stderr, "main(): started.")

	defer fmt.Fprintln(os.Stderr, "main(): terminated.")

	var tickDuration time.Duration

	var timeoutDuration time.Duration

	flag.DurationVar(&tickDuration, "tick", 50*time.Microsecond, "tick duration for the simulator")

	flag.DurationVar(&timeoutDuration, "timeout", 10*time.Second, "timeout until main() stops the simulator")

	flag.Parse()

	t := time.After(timeoutDuration)

	stop := make(chan bool)

	defer func() {

		close(stop)

		fmt.Fprintln(os.Stderr, "main(): closed stop channel")

	}()

	s := simulator.New(stop, tickDuration)

	go func() {

		fmt.Fprintln(os.Stderr, "main(): simulator started.")

		s.Run()

		fmt.Fprintln(os.Stderr, "main(): simulator finished.")

	}()

loop:

	for {

		select {

		case <-t:

			fmt.Fprintln(os.Stderr, "main(): sending stop to simulator")

			stop <- true

			break loop

		}

	}

	r := <-s.DoneChannel()

	fmt.Fprintf(os.Stderr, "main(): simulator statistics: %s\n", r)

}

package simulator

import (

	"fmt"

	"time"

)

// Simulator ...

type Simulator struct {

	config Config

	stop   chan bool

	done   chan Done

}

// Config ...

type Config struct {

	Duration time.Duration

}

// Done ...

type Done struct {

	Loops    uint64

	Ticks    uint64

	Defaults uint64

}

// String ...

func (d Done) String() string {

	return fmt.Sprintf("loops: %d, ticks %d, defaults %d", d.Loops, d.Ticks, d.Defaults)

}

// New ...

func New(stop chan bool, tickDuration time.Duration) *Simulator {

	c := Config{Duration: tickDuration}

	return &Simulator{

		config: c,

		stop:   stop,

	}

}

// DoneChannel ...

func (s *Simulator) DoneChannel() chan Done {

	return s.done

}

// Run ...

func (s *Simulator) Run() {

	s.done = make(chan Done)

	defer close(s.done)

	tick := time.Tick(s.config.Duration)

	loops := uint64(0)

	ticks := uint64(0)

	defaults := uint64(0)

	for {

		select {

		case <-s.stop:

			s.done <- Done{

				Loops:    loops,

				Ticks:    ticks,

				Defaults: defaults,

			}

			return

		case <-tick:

			ticks++

		default:

			defaults++

		}

		loops++

	}

}