fix(proxy): drain submits before shutdown

Co-Authored-By: Virgil <virgil@lethean.io>

state_impl.go

@@ -283,10 +283,6 @@ func (p *Proxy) Stop() {
 		for _, server := range p.servers {
 			server.Stop()
 		}
-		p.closeAllMiners()
-		if splitter, ok := p.splitter.(interface{ Disconnect() }); ok {
-			splitter.Disconnect()
-		}
 		if p.watcher != nil {
 			p.watcher.Stop()
 		}
@@ -299,6 +295,10 @@ func (p *Proxy) Stop() {
 		for p.submitCount.Load() > 0 && time.Now().Before(deadline) {
 			time.Sleep(10 * time.Millisecond)
 		}
+		p.closeAllMiners()
+		if splitter, ok := p.splitter.(interface{ Disconnect() }); ok {
+			splitter.Disconnect()
+		}
 		if p.accessLog != nil {
 			p.accessLog.Close()
 		}

state_stop_test.go

@@ -66,6 +66,48 @@ func TestProxy_Stop_Ugly(t *testing.T) {
 	}
 }
 
+func TestProxy_Stop_WaitsBeforeDisconnectingSubmitPaths(t *testing.T) {
+	serverConn, clientConn := net.Pipe()
+	defer serverConn.Close()
+
+	miner := NewMiner(clientConn, 3333, nil)
+	splitter := &blockingStopSplitter{disconnectedCh: make(chan struct{})}
+	proxyInstance := &Proxy{
+		done:     make(chan struct{}),
+		miners:   map[int64]*Miner{miner.ID(): miner},
+		splitter: splitter,
+	}
+	proxyInstance.submitCount.Store(1)
+
+	stopped := make(chan struct{})
+	go func() {
+		proxyInstance.Stop()
+		close(stopped)
+	}()
+
+	select {
+	case <-splitter.disconnectedCh:
+		t.Fatalf("expected splitter disconnect to wait for submit drain")
+	case <-stopped:
+		t.Fatalf("expected Stop to keep waiting while submits are in flight")
+	case <-time.After(50 * time.Millisecond):
+	}
+
+	proxyInstance.submitCount.Store(0)
+
+	select {
+	case <-splitter.disconnectedCh:
+	case <-time.After(time.Second):
+		t.Fatalf("expected splitter disconnect after submit drain")
+	}
+
+	select {
+	case <-stopped:
+	case <-time.After(time.Second):
+		t.Fatalf("expected Stop to finish after submit drain")
+	}
+}
+
 type stubSplitter struct {
 	disconnected bool
 }
@@ -78,3 +120,18 @@ func (s *stubSplitter) Tick(ticks uint64)           {}
 func (s *stubSplitter) GC()                         {}
 func (s *stubSplitter) Upstreams() UpstreamStats    { return UpstreamStats{} }
 func (s *stubSplitter) Disconnect()                 { s.disconnected = true }
+
+type blockingStopSplitter struct {
+	disconnectedCh chan struct{}
+}
+
+func (s *blockingStopSplitter) Connect()                    {}
+func (s *blockingStopSplitter) OnLogin(event *LoginEvent)   {}
+func (s *blockingStopSplitter) OnSubmit(event *SubmitEvent) {}
+func (s *blockingStopSplitter) OnClose(event *CloseEvent)   {}
+func (s *blockingStopSplitter) Tick(ticks uint64)           {}
+func (s *blockingStopSplitter) GC()                         {}
+func (s *blockingStopSplitter) Upstreams() UpstreamStats    { return UpstreamStats{} }
+func (s *blockingStopSplitter) Disconnect() {
+	close(s.disconnectedCh)
+}