Make event-handlers edge-triggered and move socket-state to Dart.

runtime/bin/eventhandler_macos.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_MACOS_H_
 #define BIN_EVENTHANDLER_MACOS_H_
 
 #if !defined(BIN_EVENTHANDLER_H_)
 #error Do not include eventhandler_macos.h directly; use eventhandler.h instead.
 #endif
 
 #include <unistd.h>
+#include <errno.h>
 #include <sys/event.h>  // NOLINT
 #include <sys/socket.h>
 
 #include "platform/hashmap.h"
 
 
 namespace dart {
 namespace bin {
 
 class InterruptMessage {
  public:
   intptr_t id;
   Dart_Port dart_port;
   int64_t data;
 };
 
 
-enum PortDataFlags {
-  kClosedRead = 0,
-  kClosedWrite = 1,
-};
-
-
 class SocketData {
  public:
   explicit SocketData(intptr_t fd)
       : fd_(fd),
         port_(0),
         mask_(0),
-        flags_(0),
-        read_tracked_by_kqueue_(false),
-        write_tracked_by_kqueue_(false) {
+        tracked_by_kqueue_(false) {
     ASSERT(fd_ != -1);
   }
 
   bool HasReadEvent();
   bool HasWriteEvent();
 
   void ShutdownRead() {
     shutdown(fd_, SHUT_RD);
-    MarkClosedRead();
   }
 
   void ShutdownWrite() {
     shutdown(fd_, SHUT_WR);
-    MarkClosedWrite();
   }
 
   void Close() {
     port_ = 0;
     mask_ = 0;
-    flags_ = 0;
     close(fd_);
     fd_ = -1;
   }
 
   bool IsListeningSocket() { return (mask_ & (1 << kListeningSocket)) != 0; }
   bool IsPipe() { return (mask_ & (1 << kPipe)) != 0; }
-  bool IsClosedRead() { return (flags_ & (1 << kClosedRead)) != 0; }
-  bool IsClosedWrite() { return (flags_ & (1 << kClosedWrite)) != 0; }
-
-  void MarkClosedRead() { flags_ |= (1 << kClosedRead); }
-  void MarkClosedWrite() { flags_ |= (1 << kClosedWrite); }
 
   void SetPortAndMask(Dart_Port port, intptr_t mask) {
     ASSERT(fd_ != -1);
     port_ = port;
     mask_ = mask;
   }
 
   intptr_t fd() { return fd_; }
   Dart_Port port() { return port_; }
   intptr_t mask() { return mask_; }
-  bool read_tracked_by_kqueue() { return read_tracked_by_kqueue_; }
-  void set_read_tracked_by_kqueue(bool value) {
-    read_tracked_by_kqueue_ = value;
-  }
-  bool write_tracked_by_kqueue() { return write_tracked_by_kqueue_; }
-  void set_write_tracked_by_kqueue(bool value) {
-    write_tracked_by_kqueue_ = value;
+  bool tracked_by_kqueue() { return tracked_by_kqueue_; }
+  void set_tracked_by_kqueue(bool value) {
+    tracked_by_kqueue_ = value;
   }
 
  private:
   intptr_t fd_;
   Dart_Port port_;
   intptr_t mask_;
-  intptr_t flags_;
-  bool read_tracked_by_kqueue_;
-  bool write_tracked_by_kqueue_;
+  bool tracked_by_kqueue_;
 };
 
 
 class EventHandlerImplementation {
  public:
   EventHandlerImplementation();
   ~EventHandlerImplementation();
 
   // Gets the socket data structure for a given file
   // descriptor. Creates a new one if one is not found.
-  SocketData* GetSocketData(intptr_t fd);
+  SocketData* GetSocketData(intptr_t fd, bool* is_new);
   void SendData(intptr_t id, Dart_Port dart_port, int64_t data);
   void Start(EventHandler* handler);
   void Shutdown();
 
  private:
   int64_t GetTimeout();
   void HandleEvents(struct kevent* events, int size);
   void HandleTimeout();
   static void EventHandlerEntry(uword args);
   void WakeupHandler(intptr_t id, Dart_Port dart_port, int64_t data);
   void HandleInterruptFd();
   void SetPort(intptr_t fd, Dart_Port dart_port, intptr_t mask);
   intptr_t GetEvents(struct kevent* event, SocketData* sd);
   static void* GetHashmapKeyFromFd(intptr_t fd);
   static uint32_t GetHashmapHashFromFd(intptr_t fd);
 
   HashMap socket_map_;
   TimeoutQueue timeout_queue_;
   bool shutdown_;
   int interrupt_fds_[2];
   int kqueue_fd_;
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_EVENTHANDLER_MACOS_H_