vendor: update buildkit to v0.16.0-rc2

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/google.golang.org/grpc/server.go

@@ -33,8 +33,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	"golang.org/x/net/trace"
-
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/encoding"
@@ -74,9 +72,6 @@ func init() {
 		return srv.isRegisteredMethod(method)
 	}
 	internal.ServerFromContext = serverFromContext
-	internal.DrainServerTransports = func(srv *Server, addr string) {
-		srv.drainServerTransports(addr)
-	}
 	internal.AddGlobalServerOptions = func(opt ...ServerOption) {
 		globalServerOptions = append(globalServerOptions, opt...)
 	}
@@ -134,12 +129,13 @@ type Server struct {
 	drain    bool
 	cv       *sync.Cond              // signaled when connections close for GracefulStop
 	services map[string]*serviceInfo // service name -> service info
-	events   trace.EventLog
+	events   traceEventLog
 
 	quit               *grpcsync.Event
 	done               *grpcsync.Event
 	channelzRemoveOnce sync.Once
-	serveWG            sync.WaitGroup // counts active Serve goroutines for GracefulStop
+	serveWG            sync.WaitGroup // counts active Serve goroutines for Stop/GracefulStop
+	handlersWG         sync.WaitGroup // counts active method handler goroutines
 
 	channelzID *channelz.Identifier
 	czData     *channelzData
@@ -176,6 +172,7 @@ type serverOptions struct {
 	headerTableSize       *uint32
 	numServerWorkers      uint32
 	recvBufferPool        SharedBufferPool
+	waitForHandlers       bool
 }
 
 var defaultServerOptions = serverOptions{
@@ -573,6 +570,21 @@ func NumStreamWorkers(numServerWorkers uint32) ServerOption {
 	})
 }
 
+// WaitForHandlers cause Stop to wait until all outstanding method handlers have
+// exited before returning.  If false, Stop will return as soon as all
+// connections have closed, but method handlers may still be running. By
+// default, Stop does not wait for method handlers to return.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WaitForHandlers(w bool) ServerOption {
+	return newFuncServerOption(func(o *serverOptions) {
+		o.waitForHandlers = w
+	})
+}
+
 // RecvBufferPool returns a ServerOption that configures the server
 // to use the provided shared buffer pool for parsing incoming messages. Depending
 // on the application's workload, this could result in reduced memory allocation.
@@ -656,7 +668,7 @@ func NewServer(opt ...ServerOption) *Server {
 	s.cv = sync.NewCond(&s.mu)
 	if EnableTracing {
 		_, file, line, _ := runtime.Caller(1)
-		s.events = trace.NewEventLog("grpc.Server", fmt.Sprintf("%s:%d", file, line))
+		s.events = newTraceEventLog("grpc.Server", fmt.Sprintf("%s:%d", file, line))
 	}
 
 	if s.opts.numServerWorkers > 0 {
@@ -932,6 +944,12 @@ func (s *Server) handleRawConn(lisAddr string, rawConn net.Conn) {
 		return
 	}
 
+	if cc, ok := rawConn.(interface {
+		PassServerTransport(transport.ServerTransport)
+	}); ok {
+		cc.PassServerTransport(st)
+	}
+
 	if !s.addConn(lisAddr, st) {
 		return
 	}
@@ -941,15 +959,6 @@ func (s *Server) handleRawConn(lisAddr string, rawConn net.Conn) {
 	}()
 }
 
-func (s *Server) drainServerTransports(addr string) {
-	s.mu.Lock()
-	conns := s.conns[addr]
-	for st := range conns {
-		st.Drain("")
-	}
-	s.mu.Unlock()
-}
-
 // newHTTP2Transport sets up a http/2 transport (using the
 // gRPC http2 server transport in transport/http2_server.go).
 func (s *Server) newHTTP2Transport(c net.Conn) transport.ServerTransport {
@@ -1010,9 +1019,11 @@ func (s *Server) serveStreams(ctx context.Context, st transport.ServerTransport,
 
 	streamQuota := newHandlerQuota(s.opts.maxConcurrentStreams)
 	st.HandleStreams(ctx, func(stream *transport.Stream) {
+		s.handlersWG.Add(1)
 		streamQuota.acquire()
 		f := func() {
 			defer streamQuota.release()
+			defer s.handlersWG.Done()
 			s.handleStream(st, stream)
 		}
 
@@ -1721,8 +1732,8 @@ func (s *Server) handleStream(t transport.ServerTransport, stream *transport.Str
 	ctx = contextWithServer(ctx, s)
 	var ti *traceInfo
 	if EnableTracing {
-		tr := trace.New("grpc.Recv."+methodFamily(stream.Method()), stream.Method())
-		ctx = trace.NewContext(ctx, tr)
+		tr := newTrace("grpc.Recv."+methodFamily(stream.Method()), stream.Method())
+		ctx = newTraceContext(ctx, tr)
 		ti = &traceInfo{
 			tr: tr,
 			firstLine: firstLine{
@@ -1911,6 +1922,10 @@ func (s *Server) stop(graceful bool) {
 		s.serverWorkerChannelClose()
 	}
 
+	if graceful || s.opts.waitForHandlers {
+		s.handlersWG.Wait()
+	}
+
 	if s.events != nil {
 		s.events.Finish()
 		s.events = nil