How do you use a buffered channel as a task queue with natural backpressure?

A buffered channel provides natural backpressure: the producer blocks when the queue is full, signalling the consumer cannot keep up. This prevents unbounded memory growth without any additional data structure and is idiomatic Go.

type TaskQueue struct {
    tasks chan func()
    quit  chan struct{}
}

func NewTaskQueue(bufSize, workers int) *TaskQueue {
    q := &TaskQueue{
        tasks: make(chan func(), bufSize), // bounded queue
        quit:  make(chan struct{}),
    }
    for w := 0; w < workers; w++ { go q.worker() }
    return q
}

func (q *TaskQueue) worker() {
    for {
        select {
        case <-q.quit: return
        case task := <-q.tasks: task()
        }
    }
}

// Submit blocks when queue is full — natural backpressure
func (q *TaskQueue) Submit(ctx context.Context, task func()) error {
    select {
    case q.tasks <- task:
        return nil
    case <-ctx.Done():
        return ctx.Err() // caller's deadline expired waiting for a slot
    }
}

// TrySubmit — non-blocking: drop if queue is full
func (q *TaskQueue) TrySubmit(task func()) bool {
    select {
    case q.tasks <- task: return true
    default:              return false
    }
}

func (q *TaskQueue) Shutdown() { close(q.quit) }

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