Use new atomic types from Go 1.19

This is a cleaner solution for the fix in #438 thanks to the fact that Go 1.19 now is the default and the atomic.Int64 types are automatically aligned correctly on 32 bit systems.

Using this also means that xsync.Int64 can be removed. The new atomic.Int64 type solves the issue and should be quite a lot faster as it avoids the interface conversion.

Author: Jacalz

conn.go

@@ -77,7 +77,7 @@ type Conn struct {
 	closeMu sync.Mutex
 	closing bool
 
-	pingCounter   int32
+	pingCounter   atomic.Int32
 	activePingsMu sync.Mutex
 	activePings   map[string]chan<- struct{}
 }
@@ -200,7 +200,7 @@ func (c *Conn) flate() bool {
 //
 // TCP Keepalives should suffice for most use cases.
 func (c *Conn) Ping(ctx context.Context) error {
-	p := atomic.AddInt32(&c.pingCounter, 1)
+	p := c.pingCounter.Add(1)
 
 	err := c.ping(ctx, strconv.Itoa(int(p)))
 	if err != nil {

internal/xsync/int64.go

@@ -68,7 +68,7 @@ func NetConn(ctx context.Context, c *Conn, msgType MessageType) net.Conn {
 		defer nc.writeMu.unlock()
 
 		// Prevents future writes from writing until the deadline is reset.
-		atomic.StoreInt64(&nc.writeExpired, 1)
+		nc.writeExpired.Store(1)
 	})
 	if !nc.writeTimer.Stop() {
 		<-nc.writeTimer.C
@@ -84,7 +84,7 @@ func NetConn(ctx context.Context, c *Conn, msgType MessageType) net.Conn {
 		defer nc.readMu.unlock()
 
 		// Prevents future reads from reading until the deadline is reset.
-		atomic.StoreInt64(&nc.readExpired, 1)
+		nc.readExpired.Store(1)
 	})
 	if !nc.readTimer.Stop() {
 		<-nc.readTimer.C
@@ -94,25 +94,22 @@ func NetConn(ctx context.Context, c *Conn, msgType MessageType) net.Conn {
 }
 
 type netConn struct {
-	// These must be first to be aligned on 32 bit platforms.
-	// https://github.com/nhooyr/websocket/pull/438
-	readExpired  int64
-	writeExpired int64
-
 	c       *Conn
 	msgType MessageType
 
-	writeTimer  *time.Timer
-	writeMu     *mu
-	writeCtx    context.Context
-	writeCancel context.CancelFunc
-
-	readTimer  *time.Timer
-	readMu     *mu
-	readCtx    context.Context
-	readCancel context.CancelFunc
-	readEOFed  bool
-	reader     io.Reader
+	writeTimer   *time.Timer
+	writeMu      *mu
+	writeExpired atomic.Int64
+	writeCtx     context.Context
+	writeCancel  context.CancelFunc
+
+	readTimer   *time.Timer
+	readMu      *mu
+	readExpired atomic.Int64
+	readCtx     context.Context
+	readCancel  context.CancelFunc
+	readEOFed   bool
+	reader      io.Reader
 }
 
 var _ net.Conn = &netConn{}
@@ -129,7 +126,7 @@ func (nc *netConn) Write(p []byte) (int, error) {
 	nc.writeMu.forceLock()
 	defer nc.writeMu.unlock()
 
-	if atomic.LoadInt64(&nc.writeExpired) == 1 {
+	if nc.writeExpired.Load() == 1 {
 		return 0, fmt.Errorf("failed to write: %w", context.DeadlineExceeded)
 	}
 
@@ -157,7 +154,7 @@ func (nc *netConn) Read(p []byte) (int, error) {
 }
 
 func (nc *netConn) read(p []byte) (int, error) {
-	if atomic.LoadInt64(&nc.readExpired) == 1 {
+	if nc.readExpired.Load() == 1 {
 		return 0, fmt.Errorf("failed to read: %w", context.DeadlineExceeded)
 	}
 
@@ -209,7 +206,7 @@ func (nc *netConn) SetDeadline(t time.Time) error {
 }
 
 func (nc *netConn) SetWriteDeadline(t time.Time) error {
-	atomic.StoreInt64(&nc.writeExpired, 0)
+	nc.writeExpired.Store(0)
 	if t.IsZero() {
 		nc.writeTimer.Stop()
 	} else {
@@ -223,7 +220,7 @@ func (nc *netConn) SetWriteDeadline(t time.Time) error {
 }
 
 func (nc *netConn) SetReadDeadline(t time.Time) error {
-	atomic.StoreInt64(&nc.readExpired, 0)
+	nc.readExpired.Store(0)
 	if t.IsZero() {
 		nc.readTimer.Stop()
 	} else {

netconn.go

@@ -11,11 +11,11 @@ import (
 	"io"
 	"net"
 	"strings"
+	"sync/atomic"
 	"time"
 
 	"nhooyr.io/websocket/internal/errd"
 	"nhooyr.io/websocket/internal/util"
-	"nhooyr.io/websocket/internal/xsync"
 )
 
 // Reader reads from the connection until there is a WebSocket
@@ -465,7 +465,7 @@ func (mr *msgReader) read(p []byte) (int, error) {
 type limitReader struct {
 	c     *Conn
 	r     io.Reader
-	limit xsync.Int64
+	limit atomic.Int64
 	n     int64
 }
 

read.go

@@ -12,11 +12,11 @@ import (
 	"runtime"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"syscall/js"
 
 	"nhooyr.io/websocket/internal/bpool"
 	"nhooyr.io/websocket/internal/wsjs"
-	"nhooyr.io/websocket/internal/xsync"
 )
 
 // opcode represents a WebSocket opcode.
@@ -45,7 +45,7 @@ type Conn struct {
 	ws     wsjs.WebSocket
 
 	// read limit for a message in bytes.
-	msgReadLimit xsync.Int64
+	msgReadLimit atomic.Int64
 
 	closeReadMu  sync.Mutex
 	closeReadCtx context.Context