The reason you're wanting priority select is because you are shutting down the data channel preemptively, but you can wait for an acknowledgement from the run goroutine instead:
https://play.golang.org/p/qSWluYy4ifl On Wed, 28 Aug 2019 at 18:06, T L <tapir....@gmail.com> wrote: > The old thread: > https://groups.google.com/forum/#!topic/golang-nuts/ZrVIhHCrR9o > > Go channels are flexible, but in practice, I often encountered some > situations in which channel are hard to use. > Given an example: > > import "math/rand" > > type Producer struct { > data chan int > closed chan struct{} > } > > func NewProducer() *Producer { > p := &Producer { > data: make(chan int), > closed: make(chan struct{}), > } > > go p.run() > > return p > } > > func (p *Produce) Stream() chan int { > return p.data > } > > func (p *Producer) run() { > for { > // If non-blocking cases are selected by their appearance order, > // then the following slect block is a perfect use. > select { > case(0) <-p.closed: return > case p.data <- rand.Int(): > } > } > } > > func (p *Produce) Clsoe() { > close(p.closed) > close(p.data) > } > > func main() { > p := NewProducer() > for n := p.Stream() { > // use n ... > } > } > > > If the first case in the select block in the above example has a higher > priority than the second one, > then coding will be much happier for the use cases like the above one. > > In short, the above use case requires: > * for receivers, data streaming end is notified by the close of a channel. > * for senders, data will never be sent to closed channel. > > But, as Go 1 doesn't support priority select cases, it is much tedious to > implement the code > satisfying the above listed requirements. The final implementation is > often very ugly and inefficient. > > Does anyone else also experience the pain? > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/e3015cd8-c2ec-479e-927d-b9ad762d277e%40googlegroups.com > <https://groups.google.com/d/msgid/golang-nuts/e3015cd8-c2ec-479e-927d-b9ad762d277e%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAJhgacgdNrNCsEN_-oAPAbzLwq6fhakuvPjg3%3Dyg-VLTe1hkqQ%40mail.gmail.com.
