How to make a mutable list?

Question

go

There is a list of mirror addresses.
Several goroutines work with the list.
If one of the addresses did not answer, put it at the end of the list.
If all ended up at the end of the list, an exception.
Addresses that have become unavailable are restored after 24 hours.

Answer 1

Alternatively, a list of structures of the form: address, availability flag.
Checking/setting by flags via mutex.
Nothing moves anywhere in the list.