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

runtime/bin/directory_impl.dart

-// 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.
 
 
 // Used for holding error code and error message for failed OS system calls.
 class _OSStatus {
   int _errorCode;
   String _errorMessage;
 }
 
@@ skipping 138 matching lines @@
       });
     }
   }
 
   Queue<_DirectoryOperation> _queue;
   _DirectoryOperationIsolate _isolate;
 }
 
 
 class _Directory implements Directory {
+  static final int kCreateService = 0;
+  static final int kDeleteService = 1;
 
   _Directory(String this._path)
       : _scheduler = new _DirectoryOperationScheduler();
 
   static String _createTemp(String template,
                             _OSStatus status) native "Directory_CreateTemp";
   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;
     var operation = new _DirExistsOperation(_path);
     _scheduler.enqueue(operation, (result, ignored) {
       if (result < 0) {
         if (_errorHandler != null) {
           _errorHandler("Diretory exists test failed: $_path");
         }
       } else {
         handler(result == 1);
       }
     });
   }
 
   bool existsSync() {
     int exists = _exists(_path);
     if (exists < 0) {
       throw new DirectoryException("Diretory exists test failed: $_path");
     }
     return (exists == 1);
   }
 
   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() {
     if (!_create(_path)) {
       throw new DirectoryException("Directory creation failed: $_path");
     }
   }
 
   void createTemp() {
     var handler =
@@ skipping 17 matching lines @@
       _path = result;
     } else {
       throw new DirectoryException(
           "Could not create temporary directory [$_path]: " +
           "${status._errorMessage}",
           status._errorCode);
     }
   }
 
   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() {
     if (!_delete(_path)) {
       throw new DirectoryException("Directory deletion failed: $_path");
     }
   }
 
   void list([bool recursive = false]) {
     new _DirectoryListingIsolate().spawn().then((port) {
@@ skipping 103 matching lines @@
   var _fileHandler;
   var _doneHandler;
   var _existsHandler;
   var _createHandler;
   var _createTempHandler;
   var _deleteHandler;
   var _errorHandler;
 
   String _path;
   _DirectoryOperationScheduler _scheduler;
+
+  static SendPort _directoryCreateService;
+  static SendPort _directoryDeleteService;
 }