fix query race. fix stream id collision behavior

request.go

@@ -140,6 +140,9 @@ func (m *RequestManager) newStream(
 	isQuery bool,
 	opts ...RequestOption,
 ) (string, <-chan ReqEvent, <-chan ReqClosed, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
 	var o requestOptions
 	for _, opt := range opts {
 		opt(&o)
@@ -147,6 +150,9 @@ func (m *RequestManager) newStream(
 
 	var id string
 	if o.id != "" {
+		if _, exists := m.reqs[o.id]; exists {
+			return "", nil, nil, fmt.Errorf("Stream: id %q already in use", o.id)
+		}
 		id = o.id
 	} else {
 		label := o.label
@@ -158,20 +164,11 @@ func (m *RequestManager) newStream(
 	buffer := make(chan ReqEvent, 64)
 	closed := make(chan ReqClosed, 1)
 
-	var events chan ReqEvent
+	events := make(chan ReqEvent)
-	if isQuery {
-		// Query reads directly from buffer. bufferedPipe drains asynchronously,
-		// so EOSE can close the pipe's output before all buffered EVENTs have
-		// passed through — causing Query's collect loop to exit short. Reading
-		// from the buffered channel directly avoids that race.
-		events = buffer
-	} else {
-		events = make(chan ReqEvent)
 	go func() {
 		bufferedPipe(buffer, events)
 		close(events)
 	}()
-	}
 
 	req := &request{
 		id:      id,
@@ -182,22 +179,10 @@ func (m *RequestManager) newStream(
 		isQuery: isQuery,
 	}
 
-	m.mu.Lock()
-	if _, exists := m.reqs[id]; exists {
-		m.mu.Unlock()
-		close(buffer)
-		if !isQuery {
-			// drain bufferedPipe goroutine
-			for range events {
-			}
-		}
-		return "", nil, nil, fmt.Errorf("Stream: id %q already in use", id)
-	}
 	m.reqs[id] = req
 	if m.envoy.IsConnected() {
 		m.activate(req)
 	}
-	m.mu.Unlock()
 
 	return id, events, closed, nil
 }
@@ -356,14 +341,8 @@ func (m *RequestManager) dispatchInbox(msg InboxMessage) {
 	}
 }
 
-// routeEvent, routeEOSE, and routeClosed use blocking sends into req.buffer.
+// routeEvent, routeEOSE, and routeClosed use blocking sends into req.buffer,
-// This preserves every event without dropping: req.buffer feeds either an
+// which reads eagerly into a slice buffer and cannot block the router.
-// unbounded bufferedPipe (streams) that absorbs a slow external reader, or
-// is read directly by Query's collect loop in the caller's goroutine.
-// ---
-// routeEvent, routeEOSE, and routeClosed are always called sequentially from
-// the same routeInbox goroutine via dispatchInbox. This makes it safe for
-// routeEOSE to close req.buffer: no concurrent routeEvent send can race it.
 func (m *RequestManager) routeEvent(msg InboxMessage) {
 	subID, event, err := envelope.FindSubscriptionEvent(msg.Data)
 	if err != nil {
@@ -382,6 +361,9 @@ func (m *RequestManager) routeEvent(msg InboxMessage) {
 	}
 }
 
+// routeEvent, routeEOSE, and routeClosed are always called sequentially from
+// the same routeInbox goroutine via dispatchInbox. This makes it safe for
+// routeEOSE to close req.buffer: no concurrent routeEvent send can race it.
 func (m *RequestManager) routeEOSE(msg InboxMessage) {
 	subID, err := envelope.FindEOSE(msg.Data)
 	if err != nil {