lastSent/keepAlive logic should not use wall clock

[johnhydroware]

I happened to look through the source code and saw that lastSent/lastReceived uses epoch time. But the logic for keepAlive should really use time elapsed. Therefore I suggest that
lastSent int64 and lastReceived int64 uses time.Time instead. Then when comparing times the monotonic clock will be used instead.

With the current logic the keep alive will break if the wall clock on the computer is changed.

Please advice if I have missunderstood something or if someone have a better solution.

[alsm]

I believe you are correct that this could be an issue, the problem is that those values are accessed from different goroutines so use the sync/atomic package for accessing and setting their values. It would need a new struct wrapping a time.Time and a mutex to give the same function. Don't suppose you fancy having a go at doing this?

[johnhydroware]

I can see if I get some time beginning of next week. I'm not really sure about the need for struct and mutex though. The code right now uses StoreInt64/LoadInt64.
So I should just need to define it as lastReceived atomic.Value
and then use c.lastReceived.Store(time.Now()) and c.lastReceived.Load().(time.Time) since the object stored is never mutated; when time is changed a new time object is created.

[alsm]

ok cool, hadn't used atomic.Value before, I'll look at doing that

[johnhydroware]

I have tried to make a pull request for this, put I can't seem to get the license thing to work. But I have a "Eclipse Contributor Agreement" green checkbox on my profile. I only get "This validation request is closed or unavailable." when clicking "details".