From 84b54eb7023c7f2734a85e9d9f295c4f8af9b0bd Mon Sep 17 00:00:00 2001
From: Toby <tobyxdd@gmail.com>
Date: Fri, 26 Jan 2024 11:49:19 -0800
Subject: [PATCH 1/2] fix: incorrect reconnect logic that causes blocking when
 dialing connections

---
 core/client/reconnect.go | 44 ++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/core/client/reconnect.go b/core/client/reconnect.go
index 137285f..46f72bc 100644
--- a/core/client/reconnect.go
+++ b/core/client/reconnect.go
@@ -58,52 +58,60 @@ func (rc *reconnectableClientImpl) reconnect() error {
 
 func (rc *reconnectableClientImpl) TCP(addr string) (net.Conn, error) {
 	rc.m.Lock()
-	defer rc.m.Unlock()
 	if rc.closed {
+		rc.m.Unlock()
 		return nil, coreErrs.ClosedError{}
 	}
 	if rc.client == nil {
 		// No active connection, connect first
 		if err := rc.reconnect(); err != nil {
+			rc.m.Unlock()
 			return nil, err
 		}
 	}
-	conn, err := rc.client.TCP(addr)
+	client := rc.client
+	rc.m.Unlock()
+
+	conn, err := client.TCP(addr)
 	if _, ok := err.(coreErrs.ClosedError); ok {
-		// Connection closed, reconnect
-		if err := rc.reconnect(); err != nil {
-			return nil, err
+		// Connection closed, set client to nil for reconnect next time
+		rc.m.Lock()
+		// In case the client has already been reconnected by another goroutine
+		if rc.client == client {
+			rc.client = nil
 		}
-		return rc.client.TCP(addr)
-	} else {
-		// OK or some other temporary error
-		return conn, err
+		rc.m.Unlock()
 	}
+	return conn, err
 }
 
 func (rc *reconnectableClientImpl) UDP() (HyUDPConn, error) {
 	rc.m.Lock()
-	defer rc.m.Unlock()
 	if rc.closed {
+		rc.m.Unlock()
 		return nil, coreErrs.ClosedError{}
 	}
 	if rc.client == nil {
 		// No active connection, connect first
 		if err := rc.reconnect(); err != nil {
+			rc.m.Unlock()
 			return nil, err
 		}
 	}
-	conn, err := rc.client.UDP()
+	client := rc.client
+	rc.m.Unlock()
+
+	conn, err := client.UDP()
 	if _, ok := err.(coreErrs.ClosedError); ok {
-		// Connection closed, reconnect
-		if err := rc.reconnect(); err != nil {
-			return nil, err
+		// Connection closed, set client to nil for reconnect next time
+		rc.m.Lock()
+		// In case the client has already been reconnected by another goroutine
+		if rc.client == client {
+			rc.client = nil
 		}
-		return rc.client.UDP()
-	} else {
-		// OK or some other temporary error
-		return conn, err
+		rc.m.Unlock()
 	}
+	return conn, err
 }
 
 func (rc *reconnectableClientImpl) Close() error {

From ae402d9d919df6aec334f1f1490e036c735fed07 Mon Sep 17 00:00:00 2001
From: Toby <tobyxdd@gmail.com>
Date: Fri, 26 Jan 2024 13:19:02 -0800
Subject: [PATCH 2/2] chore: code improvements

---
 core/client/reconnect.go | 53 ++++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 29 deletions(-)

diff --git a/core/client/reconnect.go b/core/client/reconnect.go
index 46f72bc..05d60b3 100644
--- a/core/client/reconnect.go
+++ b/core/client/reconnect.go
@@ -56,7 +56,11 @@ func (rc *reconnectableClientImpl) reconnect() error {
 	}
 }
 
-func (rc *reconnectableClientImpl) TCP(addr string) (net.Conn, error) {
+// clientDo calls f with the current client.
+// If the client is nil, it will first reconnect.
+// It will also detect if the client is closed, and if so,
+// set it to nil for reconnect next time.
+func (rc *reconnectableClientImpl) clientDo(f func(Client) (interface{}, error)) (interface{}, error) {
 	rc.m.Lock()
 	if rc.closed {
 		rc.m.Unlock()
@@ -72,46 +76,37 @@ func (rc *reconnectableClientImpl) TCP(addr string) (net.Conn, error) {
 	client := rc.client
 	rc.m.Unlock()
 
-	conn, err := client.TCP(addr)
+	ret, err := f(client)
 	if _, ok := err.(coreErrs.ClosedError); ok {
 		// Connection closed, set client to nil for reconnect next time
 		rc.m.Lock()
-		// In case the client has already been reconnected by another goroutine
 		if rc.client == client {
+			// This check is in case the client is already changed by another goroutine
 			rc.client = nil
 		}
 		rc.m.Unlock()
 	}
-	return conn, err
+	return ret, err
+}
+
+func (rc *reconnectableClientImpl) TCP(addr string) (net.Conn, error) {
+	if c, err := rc.clientDo(func(client Client) (interface{}, error) {
+		return client.TCP(addr)
+	}); err != nil {
+		return nil, err
+	} else {
+		return c.(net.Conn), nil
+	}
 }
 
 func (rc *reconnectableClientImpl) UDP() (HyUDPConn, error) {
-	rc.m.Lock()
-	if rc.closed {
-		rc.m.Unlock()
-		return nil, coreErrs.ClosedError{}
+	if c, err := rc.clientDo(func(client Client) (interface{}, error) {
+		return client.UDP()
+	}); err != nil {
+		return nil, err
+	} else {
+		return c.(HyUDPConn), nil
 	}
-	if rc.client == nil {
-		// No active connection, connect first
-		if err := rc.reconnect(); err != nil {
-			rc.m.Unlock()
-			return nil, err
-		}
-	}
-	client := rc.client
-	rc.m.Unlock()
-
-	conn, err := client.UDP()
-	if _, ok := err.(coreErrs.ClosedError); ok {
-		// Connection closed, set client to nil for reconnect next time
-		rc.m.Lock()
-		// In case the client has already been reconnected by another goroutine
-		if rc.client == client {
-			rc.client = nil
-		}
-		rc.m.Unlock()
-	}
-	return conn, err
 }
 
 func (rc *reconnectableClientImpl) Close() error {