Sarama's producer might qualify as interesting. https://pkg.go.dev/github.com/Shopify/sarama#example-AsyncProducer-Select You're supposed to produce messages on a channel while simultaneously listening for acks (optional) and errors (mandatory) in the same select loop.
Regards, Per Johansson On Monday, April 3, 2023 at 5:44:43 AM UTC+2 Nigel Tao wrote: I'm working on a multi-threaded C++ project. We have the equivalent of Go's channels, and are considering whether we also need to implement the equivalent of Go's select. Does anyone have interesting, non-trivial examples of a Go select statement in real code? By non-trivial, I mean that a lot of the selects that I've seen have exactly two cases, one of them doing "real work" and the other being either (1) "default" or (2) a timeout/cancel channel (e.g. ctx.Done()). In our C++ API, our channel send/recv methods already have try_send/try_recv equivalents for (1) and a timeout/cancel mechanism for (2). bcmills' "Rethinking Classical Concurrency Patterns" (https://drive.google.com/file/d/1nPdvhB0PutEJzdCq5ms6UI58dp50fcAN/view) uses select to implement higher level ResourcePool / WorkerPool APIs but select is arguably a private implementation detail. While it might not be as beautiful under the hood, I think we can already present similar APIs using C++'s std::counting_semaphore. r's "A Concurrent Window System" (https://swtch.com/~rsc/thread/cws.pdf) discusses select'ing from separate window, keyboard and mouse channels but this could arguably instead be a single channel of heterogenous elements (e.g. in C++, a std::variant). It's more interesting to select over both input and output channels, and output channels may become "ready to communicate" without new input. But again, it may be possible to work around that by downstream actors sending "I'm ready to receive" events onto the upstream actor's heterogenous input channel. The most interesting selects I have so far is the golang.org/x/net/http2 source code, whose internals have a bit of a learning curve. If anyone has other examples, please share. -- 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/19883d30-cf55-42f1-a2bc-094d240ee22en%40googlegroups.com.
