timers

pkg/controller/timers

Single-goroutine *time.Timer wrapper that papers over Go's well-known timer footguns.

Overview

SafeTimer provides safe Stop / Reset operations and exposes the channel as Chan() <-chan time.Time (returning nil when no timer is active so it blocks forever in a select). It exists because plain time.Timer.Reset after Stop returning false can leak a stale tick into the next cycle, and every component that uses timers in its event loop would otherwise re-implement the drain dance.

It must only be used from a single goroutine — there is no internal synchronisation.

Quick Start

import "github.com/haproxy-haptic/HAPTIC/pkg/controller/timers"

var t timers.SafeTimer

for {
    select {
    case event := <-eventChan:
        // Trailing-edge debounce: every event resets the countdown.
        t.Reset(5 * time.Second)
        process(event)

    case <-t.Chan():
        t.Fired() // MUST be called after receiving — clears the internal
                  // reference so Chan() goes back to nil until the next Reset.
        flush()

    case <-ctx.Done():
        t.Stop()
        return
    }
}

Fired() is easy to forget. Without it, t.timer != nil keeps reading as true even after the timer's channel was drained, so a stale reference lingers until the next Reset or Stop.

Reset implements trailing-edge debouncing. Controller event loops use it for configuration coalescing, CRD discovery settling, and drift-prevention cadence.

See Also

• pkg/controller/configchange — uses trailing-edge Reset for reinit coalescing
• pkg/controller/crdwatch — settles CRD discovery after changes
• pkg/controller/deployer — owns the drift-prevention cadence

License

Apache-2.0 — see root LICENSE.