all: use syncs.AtomicValue

Signed-off-by: Maisem Ali <maisem@tailscale.com>

net/dns/nrpt_windows.go

@@ -63,8 +63,8 @@ const _RP_FORCE = 1 // Flag for RefreshPolicyEx
 type nrptRuleDatabase struct {
 	logf               logger.Logf
 	watcher            *gpNotificationWatcher
-	isGPRefreshPending atomic.Value // of bool
-	mu                 sync.Mutex   // protects the fields below
+	isGPRefreshPending atomic.Bool
+	mu                 sync.Mutex // protects the fields below
 	ruleIDs            []string
 	isGPDirty          bool
 	writeAsGP          bool

net/dns/resolver/tsdns.go

@@ -21,7 +21,6 @@ import (
 	"strconv"
 	"strings"
 	"sync"
-	"sync/atomic"
 	"time"
 
 	dns "golang.org/x/net/dns/dnsmessage"
@@ -29,6 +28,7 @@ import (
 	"tailscale.com/net/netaddr"
 	"tailscale.com/net/tsaddr"
 	"tailscale.com/net/tsdial"
+	"tailscale.com/syncs"
 	"tailscale.com/types/dnstype"
 	"tailscale.com/types/logger"
 	"tailscale.com/util/clientmetric"
@@ -495,7 +495,7 @@ type resolvConfCache struct {
 
 // resolvConfCacheValue contains the most recent stat metadata and parsed
 // version of /etc/resolv.conf.
-var resolvConfCacheValue atomic.Value // of resolvConfCache
+var resolvConfCacheValue syncs.AtomicValue[resolvConfCache]
 
 var errEmptyResolvConf = errors.New("resolv.conf has no nameservers")
 
@@ -510,7 +510,7 @@ func stubResolverForOS() (ip netip.Addr, err error) {
 		mod:  fi.ModTime(),
 		size: fi.Size(),
 	}
-	if c, ok := resolvConfCacheValue.Load().(resolvConfCache); ok && c.mod == cur.mod && c.size == cur.size {
+	if c, ok := resolvConfCacheValue.LoadOk(); ok && c.mod == cur.mod && c.size == cur.size {
 		return c.ip, nil
 	}
 	conf, err := resolvconffile.ParseFile(resolvconffile.Path)

net/tsdial/tsdial.go

@@ -15,7 +15,6 @@ import (
 	"runtime"
 	"strings"
 	"sync"
-	"sync/atomic"
 	"syscall"
 	"time"
 
@@ -43,8 +42,6 @@ type Dialer struct {
 	// If nil, it's not used.
 	NetstackDialTCP func(context.Context, netip.AddrPort) (net.Conn, error)
 
-	peerDialControlFuncAtomic atomic.Value // of func() func(network, address string, c syscall.RawConn) error
-
 	peerClientOnce sync.Once
 	peerClient     *http.Client
 

net/tshttpproxy/tshttpproxy_windows.go

@@ -14,7 +14,6 @@ import (
 	"runtime"
 	"strings"
 	"sync"
-	"sync/atomic"
 	"syscall"
 	"time"
 	"unsafe"
@@ -22,6 +21,7 @@ import (
 	"github.com/alexbrainman/sspi/negotiate"
 	"golang.org/x/sys/windows"
 	"tailscale.com/hostinfo"
+	"tailscale.com/syncs"
 	"tailscale.com/types/logger"
 	"tailscale.com/util/cmpver"
 )
@@ -155,10 +155,10 @@ const win8dot1Ver = "6.3"
 
 // accessType is the flag we must pass to WinHttpOpen for proxy resolution
 // depending on whether or not we're running Windows < 8.1
-var accessType atomic.Value // of uint32
+var accessType syncs.AtomicValue[uint32]
 
 func getAccessFlag() uint32 {
-	if flag, ok := accessType.Load().(uint32); ok {
+	if flag, ok := accessType.LoadOk(); ok {
 		return flag
 	}
 	var flag uint32

net/tstun/tap_linux.go

@@ -341,8 +341,7 @@ func run(prog string, args ...string) error {
 }
 
 func (t *Wrapper) destMAC() [6]byte {
-	mac, _ := t.destMACAtomic.Load().([6]byte)
-	return mac
+	return t.destMACAtomic.Load()
 }
 
 func (t *Wrapper) tapWrite(buf []byte, offset int) (int, error) {

net/tstun/wrap.go

@@ -24,6 +24,7 @@ import (
 	"tailscale.com/disco"
 	"tailscale.com/net/packet"
 	"tailscale.com/net/tsaddr"
+	"tailscale.com/syncs"
 	"tailscale.com/tstime/mono"
 	"tailscale.com/types/ipproto"
 	"tailscale.com/types/key"
@@ -82,9 +83,9 @@ type Wrapper struct {
 	// you might need to add a pad32.Four field here.
 	lastActivityAtomic mono.Time // time of last send or receive
 
-	destIPActivity atomic.Value // of map[netip.Addr]func()
-	destMACAtomic  atomic.Value // of [6]byte
-	discoKey       atomic.Value // of key.DiscoPublic
+	destIPActivity syncs.AtomicValue[map[netip.Addr]func()]
+	destMACAtomic  syncs.AtomicValue[[6]byte]
+	discoKey       syncs.AtomicValue[key.DiscoPublic]
 
 	// buffer stores the oldest unconsumed packet from tdev.
 	// It is made a static buffer in order to avoid allocations.
@@ -247,8 +248,8 @@ func (t *Wrapper) isSelfDisco(p *packet.Parsed) bool {
 		return false
 	}
 	discoSrc := key.DiscoPublicFromRaw32(mem.B(discobs))
-	selfDiscoPub, ok := t.discoKey.Load().(key.DiscoPublic)
-	return ok && selfDiscoPub == discoSrc
+	selfDiscoPub := t.discoKey.Load()
+	return selfDiscoPub == discoSrc
 }
 
 func (t *Wrapper) Close() error {
@@ -543,7 +544,7 @@ func (t *Wrapper) Read(buf []byte, offset int) (int, error) {
 	defer parsedPacketPool.Put(p)
 	p.Decode(buf[offset : offset+n])
 
-	if m, ok := t.destIPActivity.Load().(map[netip.Addr]func()); ok {
+	if m := t.destIPActivity.Load(); m != nil {
 		if fn := m[p.Dst.Addr()]; fn != nil {
 			fn()
 		}