workerpool

Generic, type-safe handy worker pool in Go.

It executes tasks using a fixed number of worker goroutines passed to the pool constructor.

Task submission is coordinated through a buffered channel. The buffer size is configurable and defines the maximum number of tasks that can be queued before backpressure is applied. When the buffer is full, Submit blocks until capacity becomes available.

The pool supports both immediate cancellation via context and graceful shutdown.

Immediate cancellation stops workers and drops queued tasks that have not yet started execution, while graceful shutdown drains all queued tasks and waits for completion. In both cases, in-flight tasks are allowed to complete.

Install

go get github.com/alesr/workerpool

How:

type bazooka struct {
	ammo      uint8
	targetID  string
	bodyCount *atomic.Int32
}

// Do simulate some bazooking
func (b *bazooka) Do(ctx context.Context) {
	b.ammo--
	fmt.Fprintln(os.Stderr, "bazooking: "+b.targetID)
	b.bodyCount.Add(1)
}

func main() {
	pool := workerpool.New[*bazooka](context.TODO(), 3)

	var bodyCount atomic.Int32
	
	bazookas := []bazooka{
		{ammo: 69, targetID: "foo-id", bodyCount: &bodyCount},
		{ammo: 42, targetID: "bar-id", bodyCount: &bodyCount},
		{ammo: 11, targetID: "qux-id", bodyCount: &bodyCount},
	}
	
	for i := range bazookas {
		_ = pool.Submit(context.TODO(), &bazookas[i])
	}
	
	_ = pool.GracefulShutdown()
	
	fmt.Printf("Body count: %d\n", bodyCount.Load())	
}