wintun: Check for user close in read loop regardless the load

Do the WaitForSingleObject() always to provide high-load responsiveness.

Reorder events so TUN_SIGNAL_CLOSE has priority over
TUN_SIGNAL_DATA_AVAIL, to provide high-load responsiveness at all.

Signed-off-by: Simon Rozman <simon@rozman.si>

diff --git a/tun/tun_windows.go b/tun/tun_windows.go
index f284baf89138146ce6f948c8d781cf8ff76fb5c5..687057a5f7bad3d6f4599c0a314b8d8b17f46fce 100644 (file)
--- a/tun/tun_windows.go
+++ b/tun/tun_windows.go
@@ -22,10 +22,10 @@ const (
 )
 
 const (
-       TUN_SIGNAL_DATA_AVAIL = 0
-       TUN_SIGNAL_CLOSE      = 1
+       TUN_SIGNAL_CLOSE = iota
+       TUN_SIGNAL_DATA_AVAIL
 
-       TUN_SIGNAL_MAX = 2
+       TUN_SIGNAL_MAX
 )
 
 type tunPacket struct {
@@ -229,27 +229,25 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
                                }
                        }
 
-                       if tun.rdBuff.numPackets < TUN_MAX_PACKET_EXCHANGE || !tun.rdBuff.left {
-                               // Buffer was not full. Wait for the interface data or user close.
-                               r, err := windows.WaitForMultipleObjects(tun.signals[:], false, windows.INFINITE)
-                               if err != nil {
-                                       return 0, errors.New("Waiting for data failed: " + err.Error())
-                               }
-                               switch r {
-                               case windows.WAIT_OBJECT_0 + TUN_SIGNAL_DATA_AVAIL:
-                                       // Data is available.
-                               case windows.WAIT_ABANDONED + TUN_SIGNAL_DATA_AVAIL:
-                                       // TUN stopped. Reopen it.
-                                       tun.closeTUN()
-                                       continue
-                               case windows.WAIT_OBJECT_0 + TUN_SIGNAL_CLOSE, windows.WAIT_ABANDONED + TUN_SIGNAL_CLOSE:
-                                       return 0, errors.New("TUN closed")
-                               case windows.WAIT_TIMEOUT:
-                                       // Congratulations, we reached infinity. Let's do it again! :)
-                                       continue
-                               default:
-                                       return 0, errors.New("unexpected result from WaitForMultipleObjects")
-                               }
+                       // Wait for user close or interface data.
+                       r, err := windows.WaitForMultipleObjects(tun.signals[:], false, windows.INFINITE)
+                       if err != nil {
+                               return 0, errors.New("Waiting for data failed: " + err.Error())
+                       }
+                       switch r {
+                       case windows.WAIT_OBJECT_0 + TUN_SIGNAL_CLOSE, windows.WAIT_ABANDONED + TUN_SIGNAL_CLOSE:
+                               return 0, errors.New("TUN closed")
+                       case windows.WAIT_OBJECT_0 + TUN_SIGNAL_DATA_AVAIL:
+                               // Data is available.
+                       case windows.WAIT_ABANDONED + TUN_SIGNAL_DATA_AVAIL:
+                               // TUN stopped. Reopen it.
+                               tun.closeTUN()
+                               continue
+                       case windows.WAIT_TIMEOUT:
+                               // Congratulations, we reached infinity. Let's do it again! :)
+                               continue
+                       default:
+                               return 0, errors.New("unexpected result from WaitForMultipleObjects")
                        }
 
                        // Fill queue.