@@ -19,7 +19,7 @@ golang.org/x/sys 8f0908ab3b2457e2e15403d3697c9ef5cb4b57a9

 github.com/docker/go-units 8a7beacffa3009a9ac66bad506b18ffdd110cf97

 github.com/docker/go-connections f512407a188ecb16f31a33dbc9c4e4814afc1b03

-github.com/RackSec/srslog 365bf33cd9acc21ae1c355209865f17228ca534e

+github.com/RackSec/srslog 456df3a81436d29ba874f3590eeeee25d666f8a5

 github.com/imdario/mergo 0.2.1

 #get libnetwork packages

@@ -77,10 +77,7 @@ func DialWithTLSConfig(network, raddr string, priority Priority, tag string, tls

 		tlsConfig: tlsConfig,

 	}

-	w.Lock()

-	defer w.Unlock()

-

-	err := w.connect()

+	_, err := w.connect()

 	if err != nil {

 		return nil, err

 	}

@@ -8,8 +8,6 @@ import (

 // A Writer is a connection to a syslog server.

 type Writer struct {

-	sync.Mutex // guards conn

-

 	priority  Priority

 	tag       string

 	hostname  string

@@ -19,28 +17,48 @@ type Writer struct {

 	framer    Framer

 	formatter Formatter

+	mu   sync.RWMutex // guards conn

 	conn serverConn

 }

+// getConn provides access to the internal conn, protected by a mutex. The

+// conn is threadsafe, so it can be used while unlocked, but we want to avoid

+// race conditions on grabbing a reference to it.

+func (w *Writer) getConn() serverConn {

+	w.mu.RLock()

+	conn := w.conn

+	w.mu.RUnlock()

+	return conn

+}

+

+// setConn updates the internal conn, protected by a mutex.

+func (w *Writer) setConn(c serverConn) {

+	w.mu.Lock()

+	w.conn = c

+	w.mu.Unlock()

+}

+

 // connect makes a connection to the syslog server.

-// It must be called with w.mu held.

-func (w *Writer) connect() (err error) {

-	if w.conn != nil {

+func (w *Writer) connect() (serverConn, error) {

+	conn := w.getConn()

+	if conn != nil {

 		// ignore err from close, it makes sense to continue anyway

-		w.conn.close()

-		w.conn = nil

+		conn.close()

+		w.setConn(nil)

 	}

-	var conn serverConn

 	var hostname string

+	var err error

 	dialer := w.getDialer()

 	conn, hostname, err = dialer.Call()

 	if err == nil {

-		w.conn = conn

+		w.setConn(conn)

 		w.hostname = hostname

-	}

-	return

+		return conn, nil

+	} else {

+		return nil, err

+	}

 }

 // SetFormatter changes the formatter function for subsequent messages.

@@ -59,14 +77,17 @@ func (w *Writer) Write(b []byte) (int, error) {

 	return w.writeAndRetry(w.priority, string(b))

 }

+// WriteWithPriority sends a log message with a custom priority

+func (w *Writer) WriteWithPriority(p Priority, b []byte) (int, error) {

+	return w.writeAndRetry(p, string(b))

+}

+

 // Close closes a connection to the syslog daemon.

 func (w *Writer) Close() error {

-	w.Lock()

-	defer w.Unlock()

-

-	if w.conn != nil {

-		err := w.conn.close()

-		w.conn = nil

+	conn := w.getConn()

+	if conn != nil {

+		err := conn.close()

+		w.setConn(nil)

 		return err

 	}

 	return nil

@@ -131,29 +152,29 @@ func (w *Writer) Debug(m string) (err error) {

 func (w *Writer) writeAndRetry(p Priority, s string) (int, error) {

 	pr := (w.priority & facilityMask) | (p & severityMask)

-	w.Lock()

-	defer w.Unlock()

-

-	if w.conn != nil {

-		if n, err := w.write(pr, s); err == nil {

+	conn := w.getConn()

+	if conn != nil {

+		if n, err := w.write(conn, pr, s); err == nil {

 			return n, err

 		}

 	}

-	if err := w.connect(); err != nil {

+

+	var err error

+	if conn, err = w.connect(); err != nil {

 		return 0, err

 	}

-	return w.write(pr, s)

+	return w.write(conn, pr, s)

 }

 // write generates and writes a syslog formatted string. It formats the

 // message based on the current Formatter and Framer.

-func (w *Writer) write(p Priority, msg string) (int, error) {

+func (w *Writer) write(conn serverConn, p Priority, msg string) (int, error) {

 	// ensure it ends in a \n

 	if !strings.HasSuffix(msg, "\n") {

 		msg += "\n"

 	}

-	err := w.conn.writeString(w.framer, w.formatter, p, w.hostname, w.tag, msg)

+	err := conn.writeString(w.framer, w.formatter, p, w.hostname, w.tag, msg)

 	if err != nil {

 		return 0, err

 	}