On Sunday, November 6, 2016 at 12:00:33 AM UTC-4, Keith Randall wrote: > > > You cannot modify the map in another goroutine while iterating. Iterating > is considered a read operation for the entire duration of the read. Writes > happening simultaneously with reads are a data race. > "Entire duration" is the thing that's tripping you up, I think. You can't > release the read lock inside the for loop. > I'm afraid that for your use case you would need to read all the entries > (at least the keys) out of the map under a single read lock. >
Is this still technically a "data race" though? It seems logically that the only memory read operation is happening in range clause evaluation, and locking around that should prevent concurrent map access. While it's a logical race in that the results are probably not really useful, I know I tried this once out of curiosity and the race detector does not report any problems with that locking pattern. -- 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. For more options, visit https://groups.google.com/d/optout.
