Stack backoff rework (#83)

* huge Stack backoff rework

* lneto bump: huge Stack backoff rework

internal/backoff.go

@@ -4,13 +4,31 @@ import (
 	"time"
 )
 
-// ConnRWBackoff implements exponential backoff suitable for TCP connection
+// BackoffConnRW implements exponential backoff suitable for TCP connection
 // read/write polling. It starts at 1us and caps at 5ms, doubling on each consecutive backoff.
-func ConnRWBackoff(consecutiveBackoffs int) {
+func BackoffConnRW(consecutiveBackoffs uint) {
 	const (
-		minWait        = uint32(time.Microsecond) >> 1
+		minWait        = uint32(time.Microsecond)
 		maxWait        = 5 * uint32(time.Millisecond)
-		maxShift       = 23
+		maxShift       = 22
+		_overflowCheck = minWait << maxShift
+	)
+	wait := minWait << min(consecutiveBackoffs, maxShift)
+	if wait > maxWait {
+		wait = maxWait
+	}
+	time.Sleep(time.Duration(wait))
+}
+
+// BackoffStackProto implements exponential backoff suitable for stack-level
+// protocol processing polling. It starts at 1us and caps at 100ms, doubling on each consecutive backoff.
+func BackoffStackProto(consecutiveBackoffs uint) {
+	const (
+		minWait = uint32(time.Microsecond)
+		maxWait = 100 * uint32(time.Millisecond)
+
+		// Statically calculated numbers below.
+		maxShift       = 22
 		_overflowCheck = minWait << maxShift
 	)
 	wait := minWait << min(consecutiveBackoffs, maxShift)

internal/ring.go

@@ -271,20 +271,6 @@ func (r *Ring) addOff(a, b int) int {
 	return result
 }
 
-func max(a, b int) int {
-	if a > b {
-		return a
-	}
-	return b
-}
-
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 func (r *Ring) string() string {
 	var b bytes.Buffer
 	r2 := *r