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

runtime/bin/eventhandler_macos.h

Index: runtime/bin/eventhandler_macos.h
diff --git a/runtime/bin/eventhandler_macos.h b/runtime/bin/eventhandler_macos.h
index cb765c64c8bf8c92aed931a91af9e50971e4b42d..96865669c050e5ad4f5333e904decf2197719e3a 100644
--- a/runtime/bin/eventhandler_macos.h
+++ b/runtime/bin/eventhandler_macos.h
@@ -10,6 +10,7 @@
 #endif
 
 #include <unistd.h>
+#include <errno.h>
 #include <sys/event.h>  // NOLINT
 #include <sys/socket.h>
 
@@ -27,21 +28,13 @@ class InterruptMessage {
 };
 
 
-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);
   }
 
@@ -50,29 +43,21 @@ class SocketData {
 
   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);
@@ -83,22 +68,16 @@ class SocketData {
   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_;
 };
 
 
@@ -109,7 +88,7 @@ class 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();