The problem seems to be that you're using runtime.GOMAXPROCS. The fact that using GOMAXPROCS causes a deadlock is probably a bug, but it's an easy one to work around - just don't call it :)
FWIW here's a version of your code that I'd consider a little more idiomatic. https://play.golang.org/p/ufLXXX1zbrn - it reports true when an operation succeeds rather than when it fails (think reading from a channel or from a map). - it removes the unnecessary (and probably wrong) atomic load - it allows direct access to the channel for reading (and select etc) - no need to hide it behind the Read method. - mutex fields are very often named "mu" cheers, rog. On Sat, 31 Aug 2019 at 23:13, robert engels <reng...@ix.netcom.com> wrote: > The code at https://play.golang.org/p/9ZdPVvwyaYK > <https://play.golang.org/p/JRSEPU3Uf17> > > should not deadlock. But it reports: > > fatal error: all goroutines are asleep - deadlock! > > > But if you look at the stack traces, you see multiple routines (sampled) > like: > > goroutine 1 [sleep]: > runtime.goparkunlock(...) > /usr/local/go/src/runtime/proc.go:307 > time.Sleep(0x3e8, 0x0) > /usr/local/go/src/runtime/time.go:105 +0x1c0 > main.main() > /tmp/sandbox327672725/prog.go:81 +0x140 > > goroutine 5 [sleep]: > runtime.goparkunlock(...) > /usr/local/go/src/runtime/proc.go:307 > time.Sleep(0x1, 0x0) > /usr/local/go/src/runtime/time.go:105 +0x1c0 > main.producer(0x430150, 0x40a0e0) > /tmp/sandbox327672725/prog.go:49 +0x60 > created by main.main > /tmp/sandbox327672725/prog.go:73 +0xe0 > > > These routines are asleep, not blocked. They will awake from sleep > (eventually) - so there cannot be a deadlock. > > I am assuming this is a limitation of the Go playground back-end, but I > can’t see it documented anywhere? Also, I’m not sure why this limitation > would exist, since if all the routines are asleep or blocked, it is > consuming no resources. > > Ideas? > > -- > 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/C7B46199-05EA-47C1-9594-200E2DD36F99%40ix.netcom.com > <https://groups.google.com/d/msgid/golang-nuts/C7B46199-05EA-47C1-9594-200E2DD36F99%40ix.netcom.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/CAJhgaciLJFC5bdB129k7ZE_7cLVRyYBpOnW2zfqFUhUNb59jJg%40mail.gmail.com.
