refactor: remove NoCopy struct; move RefCounter struct to goutils and update usage; remove internal/utils entirely

internal/utils/ref_count.go

@@ -1,54 +0,0 @@
-package utils
-
-import (
-	"sync/atomic"
-)
-
-type RefCount struct {
-	_ NoCopy
-
-	refCount uint32
-	zeroCh   chan struct{}
-}
-
-func NewRefCounter() *RefCount {
-	rc := &RefCount{
-		refCount: 1,
-		zeroCh:   make(chan struct{}),
-	}
-	return rc
-}
-
-func (rc *RefCount) Zero() <-chan struct{} {
-	return rc.zeroCh
-}
-
-func (rc *RefCount) Add() {
-	// We add before checking to ensure proper ordering
-	newV := atomic.AddUint32(&rc.refCount, 1)
-	if newV == 1 {
-		// If it was 0 before we added, that means we're incrementing after a close
-		// This is a programming error
-		panic("RefCount.Add() called after count reached zero")
-	}
-}
-
-func (rc *RefCount) Sub() {
-	// First read the current value
-	for {
-		current := atomic.LoadUint32(&rc.refCount)
-		if current == 0 {
-			// Already at zero, channel should be closed
-			return
-		}
-
-		// Try to decrement, but only if the value hasn't changed
-		if atomic.CompareAndSwapUint32(&rc.refCount, current, current-1) {
-			if current == 1 { // Was this the last reference?
-				close(rc.zeroCh)
-			}
-			return
-		}
-		// If CAS failed, someone else modified the count, try again
-	}
-}