Improved debug logs

Relates to #270

association.go

@@ -329,10 +329,10 @@ func createAssociation(config Config) *Association {
 		retryFirstWriteError:    runtime.GOOS == "linux",
 	}
 
-	a.log.Debugf("[%s] retryFirstWriteError=%v", a.name, a.retryFirstWriteError)
-
 	a.name = fmt.Sprintf("%p", a)
 
+	a.log.Debugf("[%s] retryFirstWriteError=%v", a.name, a.retryFirstWriteError)
+
 	// RFC 4690 Sec 7.2.1
 	//  o  The initial cwnd before DATA transmission or after a sufficiently
 	//     long idle period MUST be set to min(4*MTU, max (2*MTU, 4380
@@ -615,11 +615,13 @@ func (a *Association) write(packet []byte) (int, error) {
 		if err != nil {
 			var opErr *net.OpError
 			if errors.As(err, &opErr) {
-				a.log.Debugf("write failed: op='%s' err='%s'", opErr.Op, opErr.Err.Error())
+				a.log.Debugf("[%s] write failed (op='%s' err='%s'). Retrying.", a.name, opErr.Op, opErr.Err.Error())
 				if opErr.Op == "write" && opErr.Err.Error() == "operation not permitted" {
 					n, err = a.netConn.Write(packet)
 				}
 			}
+		} else {
+			a.log.Debugf("[%s] initial write succeeded", a.name)
 		}
 	}
 	return n, err