// This sample program demonstrates how to use a channel to

// monitor the amount of time the program is running and terminate

// the program if it runs too long.

package main

import (

"log"

"os"

"time"

"github.com/goinaction/code/chapter7/patterns/runner"

)

// timeout is the number of second the program has to finish.

const timeout = 3 * time.Second

// main is the entry point for the program.

func main() {

log.Println("Starting work.")

// Create a new timer value for this run.

r := runner.New(timeout)

// Add the tasks to be run.

r.Add(createTask(), createTask(), createTask())

// Run the tasks and handle the result.

if err := r.Start(); err != nil {

switch err {

case runner.ErrTimeout:

log.Println("Terminating due to timeout.")

os.Exit(1)

case runner.ErrInterrupt:

log.Println("Terminating due to interrupt.")

os.Exit(2)

}

}

log.Println("Process ended.")

}

// createTask returns an example task that sleeps for the specified

// number of seconds based on the id.

func createTask() func(int) {

return func(id int) {

log.Printf("Processor - Task #%d.", id)

time.Sleep(time.Duration(id) * time.Second)

}

}