Method Get

controller/queue.go:116–150

* If timeout less than 0, If Queue is empty, return (nil, ErrEmptyQueue). * If timeout equals to 0, block until get a value from Queue. * If timeout greater than 0, wait timeout seconds until get a value from Queue, if timeout passed, return (nil, ErrEmptyQueue).

(timeout float64)

// * If timeout greater than 0, wait timeout seconds until get a value from Queue,
// if timeout passed, return (nil, ErrEmptyQueue).
func (q *Queue) Get(timeout float64) (interface{}, error) {
	q.mutex.Lock()
	q.clearPending()
	isempty := q.isempty()
	if timeout < 0.0 && isempty {
		q.mutex.Unlock()
		return nil, ErrEmptyQueue
	}

	if !isempty {
		v := q.get()
		q.notifyPutter(nil)
		q.mutex.Unlock()
		return v, nil
	}

	e := q.newGetter()
	q.mutex.Unlock()
	w := e.Value.(waiter)

	var v interface{}
	if timeout == 0.0 {
		v = <-w
	} else {
		select {
		case v = <-w:
		case <-time.After(time.Duration(timeout) * time.Second):
			return nil, ErrEmptyQueue
		}
	}
	q.mutex.Lock()
	q.notifyPutter(e)
	q.mutex.Unlock()
	return v, nil
}

// Same as Put(-1).
func (q *Queue) PutNoWait(val interface{}) error {