Update: nope, I was wrong. Those two scenarios cannot happen. Because reading the one value in cc.ready acts as a mutex already.
On Sunday, January 21, 2024 at 5:08:35 PM UTC+1 Jason E. Aten wrote: > I like this question, as a fun puzzle to solve. Bryan's approach is > similar to how I am thinking about it. > > Reading his code (https://go.dev/play/p/BpLBYsSSqn2?v=gotip), however, I > think there are some issues: > > 1) What if there are two simultaneous calls to Broadcast that end up > closing the > same channel (on line 46) twice? A panic would ensue due to the double > close. (I've long > felt that this was a poor choice in Go's channel design, a double close > should really be fine -- the > current design means that you almost always have to protect a close() > with a separate mutex, and check if the close has already happened first). > > 2) What Signal and Broadcast are called at the same time, and the lines > are interleaved > 36, 45, 46, 38: you would get a panic from trying to send on a closed > channel, right? > > On Thursday, January 18, 2024 at 5:23:45 PM UTC+1 Bryan C. Mills wrote: > >> Now with tests (copied from >> https://cs.opensource.google/go/go/+/master:src/sync/cond_test.go;drc=4a3071696ddfb13e1a8f35f76197b7b3143492f4 >> ): >> https://go.dev/play/p/BpLBYsSSqn2?v=gotip >> >> On Wednesday, January 17, 2024 at 5:38:18 PM UTC-5 Bryan C. Mills wrote: >> >>> Perhaps something like this: >>> https://go.dev/play/p/wllkgRAtd4a >>> >>> Disclaimer: not yet tested, probably contains bugs. >>> Also, I strongly _disrecommend_ the use of condition variables, because >>> they're too bug-prone. 🙃 >>> >>> On Friday, January 12, 2024 at 2:48:09 PM UTC-5 Rochus Keller wrote: >>> >>>> > Something like this? https://go.dev/play/p/_H3kFjprAGG >>>> >>>> No, sorry. The goal is to emulate a full monitor just with channels, as >>>> demonstrated in the referenced text (see the Stack example). The Mutex is >>>> likely correct, but the Signal has yet to pass the scrutinity of the folks >>>> here. >>>> >>>> -- 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/ad4b5dd4-aa29-4d89-9de4-088eef3984bdn%40googlegroups.com.
