Have your tried building and running your application with the race detector enabled[1]? You may have a data race.
1 - https://go.dev/doc/articles/race_detector On Sunday, September 25, 2022 at 2:16:23 PM UTC-4 Bernd Fix wrote: > Hi folks, > > I am using go1.19.1 for development and see a strange panic ("invalid > memory address") in an application; the panic is definitely not > triggered by a nil dereference (the object in question is a string): > > key = peer.Key() > entry, ok := tbl.recs[key] > > The panic happens in the second line of the code. After checking that > 'tbl' and 'tbl.recs' are valid (not nil), I inserted a log line in between: > > key = peer.Key() > log.Printf("Key=%v", key) > entry, ok := tbl.recs[key] > > Now the panic happens in the log line; the object 'key' seems to have an > invalid address (but I don't know how I can check if I can't access the > object and printf, where the new panic happens, obviously doesn't know > either). > > The 'Key()' function returns a string (there is no way to return nil > from a function with a string return value that I know of), so obviously > something strange is going on. > > It even got a bit stranger when I removed the log line and tried a recover: > > defer func() { > if r := recover(); r != nil { > log.Printf("key=%s", peer.Key()) > log.Printf("key=%v", key) > } > }() > > The first log line (now) works (it delivers a valid string result), but > the second line still panics within recovery. > > Maybe I should mention that the application heavily uses channels and go > routines; I have the subjective impression that the more go routines are > running the more likely the panic occurs after some time. But maybe that > is irrelevant. > > I compiled the same source with go1.18 (the earliest version that could > compile the code), and the panic still occurs. > > Is there anthing I can do to hunt down the problem? I am happy to share > the code (it is free software anyway) and can explain how to reproduce > the panic on your own machine (I guess that running the application > might requires some explanation). > > Cheers, Bernd. > > -- 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/1c12eec5-470a-491c-b18f-741f34cecba6n%40googlegroups.com.
