add credit based mux window

2026-07-15 14:59:32 +00:00
parent ada07e0e36
commit bbe4efbe16
15 changed files with 651 additions and 139 deletions
@@ -129,6 +129,7 @@ type destMode int
 const (
 	modeEcho          destMode = iota // echo every post-handshake byte
 	modeEchoOnceClose                 // echo one read, then close the connection
+	modeBlackhole                     // accept but never read: immediate write back-pressure
 )

 type proxyInfo struct {
@@ -154,6 +155,7 @@ type mockDest struct {
 	mode       destMode
 	events     chan destEvent
 	connClosed chan struct{}
+	done       chan struct{}
 }

 func newMockDest(t *testing.T, mode destMode) *mockDest {
@@ -168,8 +170,12 @@ func newMockDest(t *testing.T, mode destMode) *mockDest {
 		mode:       mode,
 		events:     make(chan destEvent, 128),
 		connClosed: make(chan struct{}, 128),
+		done:       make(chan struct{}),
 	}
-	t.Cleanup(func() { _ = ln.Close() })
+	t.Cleanup(func() {
+		_ = ln.Close()
+		close(d.done)
+	})
 	go d.serve()
 	return d
 }
@@ -189,6 +195,10 @@ func (d *mockDest) handle(conn net.Conn) {
 		_ = conn.Close()
 		d.connClosed <- struct{}{}
 	}()
+	if d.mode == modeBlackhole {
+		<-d.done // hold the connection open without ever reading
+		return
+	}
 	br := bufio.NewReader(conn)

 	var ev destEvent