Add debug info

common/dialer/default_parallel_interface.go

@@ -36,12 +36,16 @@ func (d *DefaultDialer) dialParallelInterface(ctx context.Context, dialer net.Di
 		if err != nil {
 			select {
 			case results <- dialResult{error: E.Cause(err, "dial ", iif.Name, " (", iif.Name, ")"), primary: primary}:
+				println("reterr", primary)
 			case <-returned:
+				println("retnil", primary)
 			}
 		} else {
 			select {
-			case results <- dialResult{Conn: conn}:
+			case results <- dialResult{Conn: conn, primary: primary}:
+				println("retconn", primary)
 			case <-returned:
+				println("retclose", primary)
 				conn.Close()
 			}
 		}
@@ -64,15 +68,18 @@ func (d *DefaultDialer) dialParallelInterface(ctx context.Context, dialer net.Di
 	for {
 		select {
 		case <-fallbackChan:
+			println("start fallback")
 			fallbackCtx, fallbackCancel := context.WithCancel(ctx)
 			defer fallbackCancel()
 			for _, iif := range fallbackInterfaces {
 				go startRacer(fallbackCtx, false, iif)
 			}
 		case res := <-results:
 			if res.error == nil {
+				println("return", res.primary)
 				return res.Conn, res.primary, nil
 			}
+			println("err", res.primary)
 			errors = append(errors, res.error)
 			if len(errors) == len(primaryInterfaces)+len(fallbackInterfaces) {
 				return nil, false, E.Errors(errors...)
@@ -108,16 +115,20 @@ func (d *DefaultDialer) dialParallelInterfaceFastFallback(ctx context.Context, d
 		if err != nil {
 			select {
 			case results <- dialResult{error: E.Cause(err, "dial ", iif.Name, " (", iif.Name, ")"), primary: primary}:
+				println("freterr", primary)
 			case <-returned:
+				println("fretnil", primary)
 			}
 		} else {
 			select {
-			case results <- dialResult{Conn: conn}:
+			case results <- dialResult{Conn: conn, primary: primary}:
+				println("fretconn", primary)
 			case <-returned:
 				if primary && time.Since(startAt) <= fallbackDelay {
 					resetFastFallback(time.Time{})
 				}
 				conn.Close()
+				println("fretclose", primary)
 			}
 		}
 	}
@@ -134,8 +145,10 @@ func (d *DefaultDialer) dialParallelInterfaceFastFallback(ctx context.Context, d
 		select {
 		case res := <-results:
 			if res.error == nil {
+				println("freturn", res.primary)
 				return res.Conn, res.primary, nil
 			}
+			println("ferr", res.primary)
 			errors = append(errors, res.error)
 			if len(errors) == len(primaryInterfaces)+len(fallbackInterfaces) {
 				return nil, false, E.Errors(errors...)