go/src/cmd/internal/par/queue.go

type Queue …

type queueState …

// NewQueue returns a Queue that executes up to maxActive items in parallel.
//
// maxActive must be positive.
func NewQueue(maxActive int) *Queue { … }

// Add adds f as a work item in the queue.
//
// Add returns immediately, but the queue will be marked as non-idle until after
// f (and any subsequently-added work) has completed.
func (q *Queue) Add(f func()) { … }

// Idle returns a channel that will be closed when q has no (active or enqueued)
// work outstanding.
func (q *Queue) Idle() <-chan struct{ … }