From 33a000cb3eedc5ede05a0ecb822724f20bc1ce0b Mon Sep 17 00:00:00 2001
From: thinkAfCod <q315xia@163.com>
Date: Mon, 19 May 2025 14:44:55 +0800
Subject: [PATCH] remove write channel

---
 p2p/discover/v5_udp.go | 58 +++++++++++++-----------------------------
 1 file changed, 17 insertions(+), 41 deletions(-)

diff --git a/p2p/discover/v5_udp.go b/p2p/discover/v5_udp.go
index 08903a0d97..06e0eefe7f 100644
--- a/p2p/discover/v5_udp.go
+++ b/p2p/discover/v5_udp.go
@@ -97,7 +97,6 @@ type UDPv5 struct {
 	sendCh        chan sendRequest
 	sendNoRespCh  chan *sendNoRespRequest
 	unhandled     chan<- ReadPacket
-	writeCh       chan pendingWrite // New channel for outgoing packets
 
 	// state of dispatch
 	codec            codecV5
@@ -113,12 +112,6 @@ type UDPv5 struct {
 	wg             sync.WaitGroup
 }
 
-// pendingWrite holds data for a packet to be sent by the writeLoop.
-type pendingWrite struct {
-	toAddr netip.AddrPort
-	data   []byte
-}
-
 type sendRequest struct {
 	destID   enode.ID
 	destAddr netip.AddrPort
@@ -166,7 +159,6 @@ func ListenV5(conn UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv5, error) {
 	t.wg.Add(3)
 	go t.readLoop()
 	go t.dispatch()
-	go t.writeLoop()
 	return t, nil
 }
 
@@ -186,14 +178,13 @@ func newUDPv5(conn UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv5, error) {
 		clock:        cfg.Clock,
 		respTimeout:  cfg.V5RespTimeout,
 		// channels into dispatch
-		packetInCh:    make(chan ReadPacket, 64),
+		packetInCh:    make(chan ReadPacket, 1),
 		callCh:        make(chan *callV5),
 		callDoneCh:    make(chan *callV5),
 		sendCh:        make(chan sendRequest),
 		sendNoRespCh:  make(chan *sendNoRespRequest),
 		respTimeoutCh: make(chan *callTimeout),
 		unhandled:     cfg.Unhandled,
-		writeCh:       make(chan pendingWrite, 32), // Buffered channel for outgoing packets
 		// state of dispatch
 		codec:            v5wire.NewCodec(ln, cfg.PrivateKey, cfg.Clock, cfg.V5ProtocolID),
 		activeCallByNode: make(map[enode.ID]*callV5),
@@ -625,7 +616,6 @@ func (t *UDPv5) dispatch() {
 			t.handlePacket(p.Data, p.Addr)
 
 		case <-t.closeCtx.Done():
-			close(t.writeCh)
 			for id, queue := range t.callQueue {
 				for _, c := range queue {
 					c.err <- errClosed
@@ -766,40 +756,26 @@ func (t *UDPv5) send(toID enode.ID, toAddr netip.AddrPort, packet v5wire.Packet,
 		return nonce, err
 	}
 
+	_, err = t.conn.WriteToUDPAddrPort(enc, toAddr)
 	t.log.Trace(">> "+packet.Name(), t.logcontext...)
-
-	dataForSend := make([]byte, len(enc))
-	copy(dataForSend, enc)
-
-	pw := pendingWrite{
-		toAddr: toAddr,
-		data:   dataForSend, // codec.Encode should return a new slice, safe to pass directly.
-	}
-
-	select {
-	case t.writeCh <- pw:
-		// Packet successfully queued.
-		return nonce, nil
-	case <-t.closeCtx.Done():
-		return nonce, errClosed
-	}
+	return nonce, err
 }
 
 // writeLoop runs in its own goroutine and sends packets from the writeCh to the network.
-func (t *UDPv5) writeLoop() {
-	defer t.wg.Done()
-	for pw := range t.writeCh { // Loop continues until writeCh is closed and empty.
-		_, err := t.conn.WriteToUDPAddrPort(pw.data, pw.toAddr)
-		if netutil.IsTemporaryError(err) {
-			t.log.Debug("Temporary UDP write error", "addr", pw.toAddr, "err", err)
-		} else if err != nil {
-			if !errors.Is(err, net.ErrClosed) || !errors.Is(err, io.EOF) {
-				t.log.Warn("UDP write error", "addr", pw.toAddr, "err", err)
-			}
-			return
-		}
-	}
-}
+//func (t *UDPv5) writeLoop() {
+//	defer t.wg.Done()
+//	for pw := range t.writeCh { // Loop continues until writeCh is closed and empty.
+//		_, err := t.conn.WriteToUDPAddrPort(pw.data, pw.toAddr)
+//		if netutil.IsTemporaryError(err) {
+//			t.log.Debug("Temporary UDP write error", "addr", pw.toAddr, "err", err)
+//		} else if err != nil {
+//			if !errors.Is(err, net.ErrClosed) || !errors.Is(err, io.EOF) {
+//				t.log.Warn("UDP write error", "addr", pw.toAddr, "err", err)
+//			}
+//			return
+//		}
+//	}
+//}
 
 // readLoop runs in its own goroutine and reads packets from the network.
 func (t *UDPv5) readLoop() {