// Example provided with help from Jason Waldrip.

// Package work manages a pool of goroutines to perform work.

package work

import "sync"

// Worker must be implemented by types that want to use

// the work pool.

type Worker interface {

Task()

}

// Pool provides a pool of goroutines that can execute any Worker

// tasks that are submitted.

type Pool struct {

work chan Worker

wg sync.WaitGroup

}

// New creates a new work pool.

func New(maxGoroutines int) *Pool {

p := Pool{

work: make(chan Worker),

}

p.wg.Add(maxGoroutines)

for i := 0; i < maxGoroutines; i++ {

go func() {

for w := range p.work {

w.Task()

}

p.wg.Done()

}()

}

return &p

}

// Run submits work to the pool.

func (p *Pool) Run(w Worker) {

p.work <- w

}

// Shutdown waits for all the goroutines to shutdown.

func (p *Pool) Shutdown() {

close(p.work)

p.wg.Wait()

}