Run all directory async operations on a separate thread using native ports

runtime/bin/directory_impl.dart

Index: runtime/bin/directory_impl.dart
diff --git a/runtime/bin/directory_impl.dart b/runtime/bin/directory_impl.dart
index 598a5a4e14e5c58dfbba03bd88cb4e9146b58992..021599d37567f94cf1964f44f04429d545876d44 100644
--- a/runtime/bin/directory_impl.dart
+++ b/runtime/bin/directory_impl.dart
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
@@ -157,6 +157,8 @@ class _DirectoryOperationScheduler {
 
 
 class _Directory implements Directory {
+  static final int kCreateService = 0;
+  static final int kDeleteService = 1;
 
   _Directory(String this._path)
       : _scheduler = new _DirectoryOperationScheduler();
@@ -166,6 +168,8 @@ class _Directory implements Directory {
   static int _exists(String path) native "Directory_Exists";
   static bool _create(String path) native "Directory_Create";
   static bool _delete(String path) native "Directory_Delete";
+  static SendPort _newServicePort(int service_id)
+      native "Directory_NewServicePort";
 
   void exists() {
     var handler = (_existsHandler != null) ? _existsHandler : (result) => null;
@@ -190,15 +194,16 @@ class _Directory implements Directory {
   }
 
   void create() {
-    var handler = (_createHandler != null) ? _createHandler : () => null;
-    var operation = new _DirCreateOperation(_path);
-    _scheduler.enqueue(operation, (result, ignored) {
-      if (result) {
-        handler();
-      } else if (_errorHandler != null) {
-        _errorHandler("Directory creation failed: $_path");
-      }
-    });
+    if (_directoryCreateService == null) {
+      _directoryCreateService = _newServicePort(kCreateService);
+    }
+    _directoryCreateService.call(_path).receive((result, replyTo) {
+        if (result) {
+          if (_createHandler != null) _createHandler();
+        } else if (_errorHandler != null) {
+          _errorHandler("Directory creation failed: $_path");
+        }
+      });
   }
 
   void createSync() {
@@ -236,15 +241,16 @@ class _Directory implements Directory {
   }
 
   void delete() {
-    var handler = (_deleteHandler != null) ? _deleteHandler : () => null;
-    var operation = new _DirDeleteOperation(_path);
-    _scheduler.enqueue(operation, (result, ignored) {
-      if (result) {
-        handler();
-      } else if (_errorHandler != null) {
-        _errorHandler("Directory deletion failed: $_path");
-      }
-    });
+    if (_directoryDeleteService == null) {
+      _directoryDeleteService = _newServicePort(kDeleteService);
+    }
+    _directoryDeleteService.call(_path).receive((result, replyTo) {
+        if (result) {
+          if (_deleteHandler != null) _deleteHandler();
+        } else if (_errorHandler != null) {
+          _errorHandler("Directory deletion failed: $_path");
+        }
+      });
   }
 
   void deleteSync() {
@@ -368,4 +374,7 @@ class _Directory implements Directory {
 
   String _path;
   _DirectoryOperationScheduler _scheduler;
+
+  static SendPort _directoryCreateService;
+  static SendPort _directoryDeleteService;
 }