go-service/examples/routines/main.go

// Example routines demonstrates the use of routines and a routine manager.
package main

import "log"
import "time"
import "context"
import "math/rand"
import "git.tebibyte.media/sashakoshka/go-service/daemon"
import "git.tebibyte.media/sashakoshka/go-service/routines"

func main () {
	cow := cow { name: "cow" }
	sheep := sheep { name: "sheep" }
	horse := horse {
		name: "horse",
		sheep: &sheep,
	}
	
	manager := routines.Manager {
		Routines: []routines.Routine {
			&cow,
			&sheep,
			&horse,
		},
	}
	
	ctx, cancel := context.WithTimeout(context.Background(), time.Second * 12)
	daemon.OnSigint(cancel)
	err := manager.Run(ctx)
	if err != nil { log.Fatalln(err) }
}

type cow struct {
	name string
}

func (this *cow) Init (ctx context.Context) error {
	log.Printf("%s: waking up\n", this.name)
	defer log.Printf("%s: woke up\n", this.name)
	time.Sleep(time.Duration(float64(time.Second) * 4 * rand.Float64()))
	return nil
}

func (this *cow) Run (ctx context.Context) error {
	log.Printf("%s: running\n", this.name)
	defer log.Printf("%s: going to sleep\n", this.name)

	ticker := time.NewTicker(time.Duration(float64(time.Second) * 4 * rand.Float64()))
	defer ticker.Stop()
	
	for {
		select {
		case <- ctx.Done(): return ctx.Err()
		case <- ticker.C:   log.Printf("%s: moo\n", this.name)
		}
	}
}

type sheep struct {
	name string
	poke chan struct { }
}

func (this *sheep) Init (ctx context.Context) error {
	log.Printf("%s: waking up\n", this.name)
	defer log.Printf("%s: woke up\n", this.name)
	this.poke = make(chan struct { })
	time.Sleep(time.Duration(float64(time.Second) * 4 * rand.Float64()))
	return nil
}

func (this *sheep) Run (ctx context.Context) error {
	log.Printf("%s: running\n", this.name)
	defer log.Printf("%s: going to sleep\n", this.name)

	for {
		select {
		case <- ctx.Done(): return ctx.Err()
		case <- this.poke:  log.Printf("%s: baa\n", this.name)
		}
	}
}


type horse struct {
	name  string
	sheep *sheep
}

func (this *horse) Init (ctx context.Context) error {
	log.Printf("%s: waking up\n", this.name)
	defer log.Printf("%s: woke up\n", this.name)
	time.Sleep(time.Duration(float64(time.Second) * 4 * rand.Float64()))
	return nil
}

func (this *horse) Run (ctx context.Context) error {
	log.Printf("%s: running\n", this.name)
	defer log.Printf("%s: going to sleep\n", this.name)

	ticker := time.NewTicker(time.Duration(float64(time.Second) * 4 * rand.Float64()))
	defer ticker.Stop()
	
	for {
		select {
		case <- ctx.Done(): return ctx.Err()
		case <- ticker.C:
			if this.sheep != nil {
				log.Printf("%s: poking %s\n", this.name, this.sheep.name)
				this.sheep.poke <- struct { } { }
			}
		}
	}
}