Simple & Reliable Monitoring That Scales

When you’ve got several identical values in your code, you only store one copy. Instead of having several copies of the same thing, they all just point to this one version, which is a lot more efficient. It’s a process often called ‘interning’ in programming circles.

What singleflight does is ensure that only one of those goroutines actually runs the operation, like getting the data from the database. It allows only one ‘in-flight’ (ongoing) operation for the same piece of data (known as a ‘key’) at any given moment.

In Go, sync.Cond is a synchronization primitive, though it’s not as commonly used as its siblings like sync.Mutex or sync.WaitGroup. That said, as a Go engineer, you don’t really want to find yourself reading through code that uses sync.Cond and not have a clue what’s going on.