Sperrfreie geläufige Bitset-Zustandsverfolgung mittels atomarer bitweiser Operationen

package main
 
import (
	"fmt"
	"sync/atomic"
)
 
type AtomicBitset struct {
	bits uint64
}
 
func (b *AtomicBitset) Set(pos uint8) {
	mask := uint64(1) << pos
	for {
		old := atomic.LoadUint64(&b.bits)
		if old&mask != 0 {
			return // Bit already set
		}
		if atomic.CompareAndSwapUint64(&b.bits, old, old|mask) {
			return
		}
	}
}
 
func (b *AtomicBitset) IsSet(pos uint8) bool {
	mask := uint64(1) << pos
	return (atomic.LoadUint64(&b.bits) & mask) != 0
}
 
func main() {
	var bitset AtomicBitset
	bitset.Set(3)
	bitset.Set(60)
 
	fmt.Println("Bit 3 set?", bitset.IsSet(3))
	fmt.Println("Bit 10 set?", bitset.IsSet(10))
	fmt.Println("Bit 60 set?", bitset.IsSet(60))
}