Introduce a kSetEventMaskCommand, some cleanups in windows eventhandler

dart/runtime/bin/eventhandler.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef BIN_EVENTHANDLER_H_
 #define BIN_EVENTHANDLER_H_
 
 #include "bin/builtin.h"
 #include "bin/isolate_data.h"
 
 namespace dart {
 namespace bin {
 
 // Flags used to provide information and actions to the eventhandler
 // when sending a message about a file descriptor. These flags should
 // be kept in sync with the constants in socket_impl.dart. For more
 // information see the comments in socket_impl.dart
 enum MessageFlags {
   kInEvent = 0,
   kOutEvent = 1,
   kErrorEvent = 2,
   kCloseEvent = 3,
   kDestroyedEvent = 4,
   kCloseCommand = 8,
   kShutdownReadCommand = 9,
   kShutdownWriteCommand = 10,
   kReturnTokenCommand = 11,
+  kSetEventMaskCommand = 12,
   kListeningSocket = 16,
   kPipe = 17,
 };
 
 #define COMMAND_MASK ((1 << kCloseCommand) | \
                       (1 << kShutdownReadCommand) | \
                       (1 << kShutdownWriteCommand) | \
-                      (1 << kReturnTokenCommand))
+                      (1 << kReturnTokenCommand) | \
+                      (1 << kSetEventMaskCommand))
+#define EVENT_MASK ((1 << kInEvent) | \
+                    (1 << kOutEvent) | \
+                    (1 << kErrorEvent) | \
+                    (1 << kCloseEvent) | \
+                    (1 << kDestroyedEvent))
 #define IS_COMMAND(data, command_bit) \
     ((data & COMMAND_MASK) == (1 << command_bit))  // NOLINT
-#define ASSERT_NO_COMMAND(data) ASSERT((data & COMMAND_MASK) == 0)  // NOLINT
+#define IS_EVENT(data, event_bit) \
+    ((data & EVENT_MASK) == (1 << event_bit))  // NOLINT
+#define IS_LISTENING_SOCKET(data) \
+    ((data & (1 << kListeningSocket)) != 0)  // NOLINT
 #define TOKEN_COUNT(data) (data & ((1 << kCloseCommand) - 1))
 
 class TimeoutQueue {
  private:
   class Timeout {
    public:
     Timeout(Dart_Port port, int64_t timeout, Timeout* next)
         : port_(port), timeout_(timeout), next_(next) {}
 
     Dart_Port port() const { return port_; }
@@ skipping 162 matching lines @@
 
  private:
   friend class EventHandlerImplementation;
   EventHandlerImplementation delegate_;
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_EVENTHANDLER_H_