gops: Gops hangs if there are too many Go processes to examine

If you have more than ten (I believe) Go processes, gops will hang in goprocess/gp.go’s FindAll() function. This happens because the ‘for … range pss { …}’ loop attempts to obtain a limitCh token before starting the goroutine, but the goroutines only release their token after they have sent their reply to the found channel. Since the found channel is unbuffered and is only read from by the main code after the ‘for … range pss {}’ loop finishes, this deadlocks if the number of goroutines would ever be limited.

I think either the entire ‘for … range pss { … }’ loop needs to be in a goroutine so that it doesn’t block reading from the found channel, or the limitCh token must be released by the code before sending to found. The former change seems easier and I think it’s correct.