| // 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. |
| |
| // part of "common_patch.dart"; |
| |
| class _IOServicePorts { |
| // We limit the number of IO Service ports per isolate so that we don't |
| // spawn too many threads all at once, which can crash the VM on Windows. |
| static const int maxPorts = 32; |
| List<SendPort> _ports = <SendPort>[]; |
| List<SendPort> _freePorts = <SendPort>[]; |
| Map<int, SendPort> _usedPorts = new HashMap<int, SendPort>(); |
| |
| _IOServicePorts(); |
| |
| SendPort _getPort(int forRequestId) { |
| if (_freePorts.isEmpty && _usedPorts.length < maxPorts) { |
| final SendPort port = _newServicePort(); |
| _ports.add(port); |
| _freePorts.add(port); |
| } |
| if (!_freePorts.isEmpty) { |
| final SendPort port = _freePorts.removeLast(); |
| assert(!_usedPorts.containsKey(forRequestId)); |
| _usedPorts[forRequestId] = port; |
| return port; |
| } |
| // We have already allocated the max number of ports. Re-use an |
| // existing one. |
| final SendPort port = _ports[forRequestId % maxPorts]; |
| _usedPorts[forRequestId] = port; |
| return port; |
| } |
| |
| void _returnPort(int forRequestId) { |
| final SendPort port = _usedPorts.remove(forRequestId)!; |
| if (!_usedPorts.values.contains(port)) { |
| _freePorts.add(port); |
| } |
| } |
| |
| static SendPort _newServicePort() native "IOService_NewServicePort"; |
| } |
| |
| @patch |
| class _IOService { |
| static _IOServicePorts _servicePorts = new _IOServicePorts(); |
| static RawReceivePort? _receivePort; |
| static late SendPort _replyToPort; |
| static HashMap<int, Completer> _messageMap = new HashMap<int, Completer>(); |
| static int _id = 0; |
| |
| @patch |
| static Future _dispatch(int request, List data) { |
| int id; |
| do { |
| id = _getNextId(); |
| } while (_messageMap.containsKey(id)); |
| final SendPort servicePort = _servicePorts._getPort(id); |
| _ensureInitialize(); |
| final Completer completer = new Completer(); |
| _messageMap[id] = completer; |
| try { |
| servicePort.send(<dynamic>[id, _replyToPort, request, data]); |
| } catch (error) { |
| _messageMap.remove(id)!.complete(error); |
| if (_messageMap.length == 0) { |
| _finalize(); |
| } |
| } |
| return completer.future; |
| } |
| |
| static void _ensureInitialize() { |
| if (_receivePort == null) { |
| _receivePort = new RawReceivePort(); |
| _replyToPort = _receivePort!.sendPort; |
| _receivePort!.handler = (data) { |
| assert(data is List && data.length == 2); |
| _messageMap.remove(data[0])!.complete(data[1]); |
| _servicePorts._returnPort(data[0]); |
| if (_messageMap.length == 0) { |
| _finalize(); |
| } |
| }; |
| } |
| } |
| |
| static void _finalize() { |
| _id = 0; |
| _receivePort!.close(); |
| _receivePort = null; |
| } |
| |
| static int _getNextId() { |
| if (_id == 0x7FFFFFFF) _id = 0; |
| return _id++; |
| } |
| } |