Merge services into a shared IOService in dart:io, and use a native port.

runtime/bin/io_service_patch.dart

+// Copyright (c) 2013, 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.
+
+const int FILE_EXISTS = 0;
+const int FILE_CREATE = 1;
+const int FILE_DELETE = 2;
+const int FILE_RENAME = 3;
+const int FILE_OPEN = 4;
+const int FILE_RESOLVE_SYMBOLIC_LINKS = 5;
+const int FILE_CLOSE = 6;
+const int FILE_POSITION = 7;
+const int FILE_SET_POSITION = 8;
+const int FILE_TRUNCATE = 9;
+const int FILE_LENGTH = 10;
+const int FILE_LENGTH_FROM_PATH = 11;
+const int FILE_LAST_MODIFIED = 12;
+const int FILE_FLUSH = 13;
+const int FILE_READ_BYTE = 14;
+const int FILE_WRITE_BYTE = 15;
+const int FILE_READ = 16;
+const int FILE_READ_INTO = 17;
+const int FILE_WRITE_FROM = 18;
+const int FILE_CREATE_LINK = 19;
+const int FILE_DELETE_LINK = 20;
+const int FILE_RENAME_LINK = 21;
+const int FILE_LINK_TARGET = 22;
+const int FILE_TYPE = 23;
+const int FILE_IDENTICAL = 24;
+const int FILE_STAT = 25;
+const int SOCKET_LOOKUP = 26;
+const int SOCKET_LIST_INTERFACES = 27;
+const int SOCKET_REVERSE_LOOKUP = 28;
+const int DIRECTORY_CREATE = 29;
+const int DIRECTORY_DELETE = 30;
+const int DIRECTORY_EXISTS = 31;
+const int DIRECTORY_CREATE_TEMP = 32;
+const int DIRECTORY_LIST_START = 33;
+const int DIRECTORY_LIST_NEXT = 34;
+const int DIRECTORY_LIST_STOP = 35;
+const int DIRECTORY_RENAME = 36;
+const int SSL_PROCESS_FILTER = 37;
+
+class IOService {
+  // Lazy initialize service ports, 32 per isolate.
+  static const int _SERVICE_PORT_COUNT = 32;
+  static List<SendPort> _servicePort = new List(_SERVICE_PORT_COUNT);
+  static ReceivePort _receivePort;
+  static SendPort _replyToPort;
+  static Map<int, Completer> _messageMap = {};
+  static int _id = 0;
+
+  static Future dispatch(int request, List data) {
+    int id;
+    do {
+      id = _getNextId();
+    } while (_messageMap.containsKey(id));
+    int index = id % _SERVICE_PORT_COUNT;
+    _initialize(index);
+    var completer = new Completer();
+    _messageMap[id] = completer;
+    _servicePort[index].send([id, request, data], _replyToPort);
+    return completer.future;
+  }
+
+  static void _initialize(int index) {
+    if (_servicePort[index] == null) {
+      _servicePort[index] = _newServicePort();
+    }
+    if (_receivePort == null) {
+      _receivePort = new ReceivePort();
+      _replyToPort = _receivePort.toSendPort();
+      _receivePort.receive((data, _) {
+        assert(data is List && data.length == 2);
+        _messageMap.remove(data[0]).complete(data[1]);
+        if (_messageMap.length == 0) {
+          _id = 0;
+          _receivePort.close();
+          _receivePort = null;
+        }
+      });
+    }
+  }
+
+  static int _getNextId() {
+    if (_id == 0x7FFFFFFF) _id = 0;
+    return _id++;
+  }
+
+  static SendPort _newServicePort() native "IOService_NewServicePort";
+}