fix: synchronize service startup and shutdown (#5560)

client/proxy/proxy_wrapper.go

@@ -267,8 +267,9 @@ func (pw *Wrapper) InWorkConn(workConn net.Conn, m *msg.StartWorkConn) {
 	xl := pw.xl
 	pw.mu.RLock()
 	pxy := pw.pxy
+	running := pw.Phase == ProxyPhaseRunning
 	pw.mu.RUnlock()
-	if pxy != nil && pw.Phase == ProxyPhaseRunning {
+	if pxy != nil && running {
 		xl.Debugf("start a new work connection, localAddr: %s remoteAddr: %s", workConn.LocalAddr().String(), workConn.RemoteAddr().String())
 		go pxy.InWorkConn(workConn, m)
 	} else {

client/proxy/proxy_wrapper_test.go

@@ -0,0 +1,76 @@
+//go:build !frps
+
+package proxy
+
+import (
+	"io"
+	"net"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/fatedier/frp/pkg/msg"
+	"github.com/fatedier/frp/pkg/util/xlog"
+)
+
+type closingWorkProxy struct {
+	Proxy
+	accepted atomic.Int64
+}
+
+func (p *closingWorkProxy) InWorkConn(conn net.Conn, _ *msg.StartWorkConn) {
+	p.accepted.Add(1)
+	_ = conn.Close()
+}
+
+func assertWrapperWorkConnClosed(t *testing.T, pw *Wrapper) {
+	t.Helper()
+	conn, peer := net.Pipe()
+	defer conn.Close()
+	defer peer.Close()
+	require.NoError(t, peer.SetReadDeadline(time.Now().Add(time.Second)))
+	pw.InWorkConn(conn, &msg.StartWorkConn{})
+	_, err := peer.Read(make([]byte, 1))
+	require.ErrorIs(t, err, io.EOF)
+}
+
+func TestWrapperInWorkConnPhaseSnapshot(t *testing.T) {
+	pxy := &closingWorkProxy{}
+	pw := &Wrapper{pxy: pxy, xl: xlog.New()}
+	for _, phase := range []string{ProxyPhaseNew, ProxyPhaseWaitStart, ProxyPhaseStartErr, ProxyPhaseCheckFailed, ProxyPhaseClosed} {
+		pw.Phase = phase
+		assertWrapperWorkConnClosed(t, pw)
+	}
+	require.Zero(t, pxy.accepted.Load(), "inactive proxy received a work connection")
+	pw.Phase = ProxyPhaseRunning
+	pw.pxy = nil
+	assertWrapperWorkConnClosed(t, pw)
+	pw.pxy = pxy
+	assertWrapperWorkConnClosed(t, pw)
+	require.Equal(t, int64(1), pxy.accepted.Load())
+
+	start, done := make(chan struct{}), make(chan struct{})
+	go func() {
+		<-start
+		for range 20000 {
+			pw.mu.Lock()
+			pw.Phase = ProxyPhaseRunning
+			pw.mu.Unlock()
+			pw.mu.Lock()
+			pw.Phase = ProxyPhaseClosed
+			pw.mu.Unlock()
+		}
+		close(done)
+	}()
+	close(start)
+	for range 10000 {
+		assertWrapperWorkConnClosed(t, pw)
+	}
+	select {
+	case <-done:
+	case <-time.After(3 * time.Second):
+		t.Fatal("phase writer did not finish")
+	}
+}