Various fixes for sync socket implementation.

tests/standalone/io/raw_synchronous_socket_test.dart

+// Copyright (c) 2017, 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.
+
+import "dart:async";
+import "dart:io";
+import "dart:isolate";
+import "dart:math";
+
+import "package:async_helper/async_helper.dart";
+import "package:expect/expect.dart";
+
+const String LOOPBACK_IP_V4_STRING = "127.0.0.1";
+
+void testArguments() {
+  Expect.throws(() => RawSynchronousSocket.connectSync(null, 0));
+  Expect.throws(
+      () => RawSynchronousSocket.connectSync(LOOPBACK_IP_V4_STRING, null));
+  Expect.throws(
+      () => RawSynchronousSocket.connectSync(LOOPBACK_IP_V4_STRING, 65536));
+  Expect.throws(
+      () => RawSynchronousSocket.connectSync(LOOPBACK_IP_V4_STRING, -1));
+  Expect.throws(() =>
+      RawSynchronousSocket.connectSync(LOOPBACK_IP_V4_STRING, 0, backlog: -1));
+}
+
+// The connection attempt happens on the main Dart thread and the OS timeout can
+// be arbitrarily long, causing timeout issues on the build bots. This isn't an
+// issue with the async sockets since the lookup for a connect call happens on
+// the IO service thread.
+/*
+void testInvalidConnect() {
+  // Connect to an unknown DNS name.
+  try {
+    var socket = RawSynchronousSocket.connectSync("ko.faar.__hest__", 0);
+    Expect.fail("Failure expected");
+  } catch (e) {
+    Expect.isTrue(e is SocketException);
+  }
+
+  // Connect to an unavaliable IP-address.
+  try {
+    var socket = RawSynchronousSocket.connectSync("1.2.3.4", 0);
+    Expect.fail("Failure expected");
+  } catch (e) {
+    Expect.isTrue(e is SocketException);
+  }
+}
+*/
+
+void testSimpleConnect() {
+  asyncStart();
+  RawServerSocket.bind(InternetAddress.LOOPBACK_IP_V4, 0).then((server) {
+    var socket =
+        RawSynchronousSocket.connectSync(LOOPBACK_IP_V4_STRING, server.port);
+    server.listen((serverSocket) {
+      Expect.equals(socket.address, serverSocket.remoteAddress);
+      Expect.equals(socket.port, serverSocket.remotePort);
+      Expect.equals(socket.remoteAddress, server.address);
+      Expect.equals(socket.remotePort, server.port);
+      socket.closeSync();
+      server.close();
+      asyncEnd();
+    });
+  });
+}
+
+void testServerListenAfterConnect() {
+  asyncStart();
+  RawServerSocket.bind(InternetAddress.LOOPBACK_IP_V4, 0).then((server) {
+    Expect.isTrue(server.port > 0);
+    var client =
+        RawSynchronousSocket.connectSync(LOOPBACK_IP_V4_STRING, server.port);
+    server.listen((socket) {
+      client.closeSync();
+      server.close();
+      socket.close();
+      asyncEnd();
+    });
+  });
+}
+
+const messageSize = 1000;
+// Configuration fields for the EchoServer.
+enum EchoServerTypes {
+  // Max accumulated connections to server before close. Defaults to 1.
+  CONNECTION_COUNT,
+  // Sets the range of the fields to check in the list generated by
+  // createTestData().
+  OFFSET_END,
+  OFFSET_START,
+  // The port used to communicate with an isolate.
+  ISOLATE_SEND_PORT,
+  // The port of the newly created echo server.
+  SERVER_PORT
+}
+
+List<int> createTestData() {
+  return new List<int>.generate(messageSize, (index) => index & 0xff);
+}
+
+// Consumes data generated by a test and compares it against the original test
+// data. The optional fields, start and end, are used to compare against
+// segments of the original test data list. In other words, data.length == (end
+// - start).
+void verifyTestData(List<int> data, [int start = 0, int end]) {
+  assert(data != null);
+  List<int> expected = createTestData();
+  if (end == null) {
+    end = data.length;
+  }
+  end = min(messageSize, end);
+  Expect.equals(end - start, data.length);
+  for (int i = 0; i < (end - start); i++) {
+    Expect.equals(expected[start + i], data[i]);
+  }
+}
+
+// The echo server is spawned in a new isolate and is used to test various
+// synchronous read/write operations by echoing any data received back to the
+// sender. The server should shutdown automatically after a specified number of
+// socket disconnections (default: 1).
+Future echoServer(var sendPort) async {
+  RawServerSocket.bind(InternetAddress.LOOPBACK_IP_V4, 0).then((server) async {
+    ReceivePort receivePort = new ReceivePort();
+    Map response = {
+      EchoServerTypes.ISOLATE_SEND_PORT: receivePort.sendPort,
+      EchoServerTypes.SERVER_PORT: server.port
+    };
+    sendPort.send(response);
+    Map limits = await receivePort.first;
+    int start = limits[EchoServerTypes.OFFSET_START];
+    int end = limits[EchoServerTypes.OFFSET_END];
+    int length = end - start;
+    int connection_count = limits[EchoServerTypes.CONNECTION_COUNT] ?? 1;
+    int connections = 0;
+    sendPort = limits[EchoServerTypes.ISOLATE_SEND_PORT];
+    server.listen((client) {
+      int bytesRead = 0;
+      int bytesWritten = 0;
+      bool closedEventReceived = false;
+      List<int> data = new List<int>(length);
+      client.writeEventsEnabled = false;
+      client.listen((event) {
+        switch (event) {
+          case RawSocketEvent.READ:
+            Expect.isTrue(bytesWritten == 0);
+            Expect.isTrue(client.available() > 0);
+            var buffer = client.read(client.available());
+            data.setRange(bytesRead, bytesRead + buffer.length, buffer);
+            bytesRead += buffer.length;
+            // Once we've read all the data, we can echo it back. Otherwise,
+            // keep waiting for more bytes.
+            if (bytesRead >= length) {
+              verifyTestData(data, start, end);
+              client.writeEventsEnabled = true;
+            }
+            break;
+          case RawSocketEvent.WRITE:
+            Expect.isFalse(client.writeEventsEnabled);
+            bytesWritten +=
+                client.write(data, bytesWritten, data.length - bytesWritten);
+            if (bytesWritten < length) {
+              client.writeEventsEnabled = true;
+            } else if (bytesWritten == length) {
+              // Close the socket for writing from the server since we're done
+              // writing to this socket. The connection is closed completely
+              // after the client closes the socket for reading from the server.
+              client.shutdown(SocketDirection.SEND);
+            }
+            break;
+          case RawSocketEvent.READ_CLOSED:
+            client.close();
+            break;
+          case RawSocketEvent.CLOSED:
+            Expect.isFalse(closedEventReceived);
+            closedEventReceived = true;
+            break;
+          default:
+            throw "Unexpected event $event";
+        }
+      }, onDone: () {
+        Expect.isTrue(closedEventReceived);
+        connections++;
+        if (connections >= connection_count) {
+          server.close();
+        }
+      });
+    }, onDone: () {
+      // Let the client know we're shutting down then kill the isolate.
+      sendPort.send(null);
+      kill();
+    });
+  });
+}
+
+Future testSimpleReadWrite({bool dropReads}) async {
+  asyncStart();
+  // This test creates a server and a client connects. The client writes data
+  // to the socket and the server echos it back. The client confirms the data it
+  // reads is the same as the data sent, then closes the socket, resulting in
+  // the closing of the server, which responds on receivePort with null to
+  // specify the echo server isolate is about to be killed. If an error occurs
+  // in the echo server, the exception and stack trace are sent to receivePort,
+  // which prints the exception and stack trace before eventually throwing an
+  // error.
+  ReceivePort receivePort = new ReceivePort();
+  Isolate echo = await Isolate.spawn(echoServer, receivePort.sendPort);
+
+  Map response = await receivePort.first;
+  SendPort sendPort = response[EchoServerTypes.ISOLATE_SEND_PORT];
+  int serverInternetPort = response[EchoServerTypes.SERVER_PORT];
+
+  receivePort = new ReceivePort();
+  echo.addErrorListener(receivePort.sendPort);
+
+  Map limits = {
+    EchoServerTypes.OFFSET_START: 0,
+    EchoServerTypes.OFFSET_END: messageSize,
+    EchoServerTypes.ISOLATE_SEND_PORT: receivePort.sendPort
+  };
+  sendPort.send(limits);
+
+  try {
+    var socket = RawSynchronousSocket.connectSync(
+        LOOPBACK_IP_V4_STRING, serverInternetPort);
+    List<int> data = createTestData();
+    socket.writeFromSync(data);
+    List<int> result = socket.readSync(data.length);
+    verifyTestData(result);
+    socket.shutdown(SocketDirection.SEND);
+    socket.closeSync();
+  } catch (e, stack) {
+    print("Echo test failed in the client");
+    rethrow;
+  }
+  // Wait for the server to shutdown before finishing the test.
+  var result = await receivePort.first;
+  if (result != null) {
+    throw "Echo test failed in server!\nError: ${result[0]}\nStack trace:" +
+        " ${result[1]}";
+  }
+  asyncEnd();
+}
+
+Future testPartialRead() async {
+  asyncStart();
+  // This test is based on testSimpleReadWrite, but instead of reading the
+  // entire echoed message at once, it reads it in two calls to readIntoSync.
+  ReceivePort receivePort = new ReceivePort();
+  Isolate echo = await Isolate.spawn(echoServer, receivePort.sendPort);
+
+  Map response = await receivePort.first;
+  SendPort sendPort = response[EchoServerTypes.ISOLATE_SEND_PORT];
+  int serverInternetPort = response[EchoServerTypes.SERVER_PORT];
+  List<int> data = createTestData();
+
+  receivePort = new ReceivePort();
+  echo.addErrorListener(receivePort.sendPort);
+
+  Map limits = {
+    EchoServerTypes.OFFSET_START: 0,
+    EchoServerTypes.OFFSET_END: 1000,
+    EchoServerTypes.ISOLATE_SEND_PORT: receivePort.sendPort
+  };
+  sendPort.send(limits);
+
+  try {
+    var socket = RawSynchronousSocket.connectSync(
+        LOOPBACK_IP_V4_STRING, serverInternetPort);
+    int half_length = (data.length / 2).toInt();
+
+    // Send the full data list to the server.
+    socket.writeFromSync(data);
+    List<int> result = new List<int>(data.length);
+
+    // Read half at a time and check that there's still more bytes available.
+    socket.readIntoSync(result, 0, half_length);
+    verifyTestData(result.sublist(0, half_length), 0, half_length);
+    Expect.isTrue(socket.available() == (data.length - half_length));
+
+    // Read the second half and verify again.
+    socket.readIntoSync(result, half_length);
+    verifyTestData(result);
+    Expect.isTrue(socket.available() == 0);
+
+    socket.closeSync();
+  } catch (e, stack) {
+    print("Echo test failed in the client.");
+    rethrow;
+  }
+  // Wait for the server to shutdown before finishing the test.
+  var result = await receivePort.first;
+  if (result != null) {
+    throw "Echo test failed in server!\nError: ${result[0]}\nStack trace:" +
+        " ${result[1]}";
+  }
+  asyncEnd();
+}
+
+Future testPartialWrite() async {
+  asyncStart();
+  // This test is based on testSimpleReadWrite, but instead of writing the
+  // entire data buffer at once, it writes different parts of the buffer over
+  // multiple calls to writeFromSync.
+  ReceivePort receivePort = new ReceivePort();
+  Isolate echo = await Isolate.spawn(echoServer, receivePort.sendPort);
+
+  Map response = await receivePort.first;
+  List<int> data = createTestData();
+  SendPort sendPort = response[EchoServerTypes.ISOLATE_SEND_PORT];
+  int startOffset = 32;
+  int endOffset = (data.length / 2).toInt();
+  int serverInternetPort = response[EchoServerTypes.SERVER_PORT];
+
+  receivePort = new ReceivePort();
+  echo.addErrorListener(receivePort.sendPort);
+
+  Map limits = {
+    EchoServerTypes.OFFSET_START: startOffset,
+    EchoServerTypes.OFFSET_END: endOffset,
+    EchoServerTypes.ISOLATE_SEND_PORT: receivePort.sendPort
+  };
+  sendPort.send(limits);
+  try {
+    var socket = RawSynchronousSocket.connectSync(
+        LOOPBACK_IP_V4_STRING, serverInternetPort);
+    List<int> data = createTestData();
+
+    // Write a subset of data to the server.
+    socket.writeFromSync(data, startOffset, endOffset);
+
+    // Grab the response and verify it's correct.
+    List<int> result = new List<int>(endOffset - startOffset);
+    socket.readIntoSync(result);
+
+    Expect.equals(result.length, endOffset - startOffset);
+    verifyTestData(result, startOffset, endOffset);
+    socket.closeSync();
+  } catch (e, stack) {
+    print("Echo test failed in the client.");
+    rethrow;
+  }
+
+  // Wait for the server to shutdown before finishing the test.
+  var result = await receivePort.first;
+  if (result != null) {
+    throw "Echo test failed in server!\nError: ${result[0]}\nStack trace:" +
+        " ${result[1]}";
+  }
+  asyncEnd();
+}
+
+Future testShutdown() async {
+  asyncStart();
+  // This test creates a server and a client connects. The client then tries to
+  // perform various operations after being shutdown in a specific direction, to
+  // ensure reads or writes cannot be performed if the socket has been shutdown
+  // for reading or writing.
+  ReceivePort receivePort = new ReceivePort();
+  Isolate echo = await Isolate.spawn(echoServer, receivePort.sendPort);
+
+  Map response = await receivePort.first;
+  SendPort sendPort = response[EchoServerTypes.ISOLATE_SEND_PORT];
+  int serverInternetPort = response[EchoServerTypes.SERVER_PORT];
+  List<int> data = createTestData();
+
+  receivePort = new ReceivePort();
+  echo.addErrorListener(receivePort.sendPort);
+
+  Map limits = {
+    EchoServerTypes.OFFSET_START: 0,
+    EchoServerTypes.OFFSET_END: data.length,
+    EchoServerTypes.ISOLATE_SEND_PORT: receivePort.sendPort,
+    // Tell the server to shutdown after 3 sockets disconnect.
+    EchoServerTypes.CONNECTION_COUNT: 3
+  };
+  sendPort.send(limits);
+
+  try {
+    var socket = RawSynchronousSocket.connectSync(
+        LOOPBACK_IP_V4_STRING, serverInternetPort);
+
+    // Close from both directions. Shouldn't be able to read/write to the
+    // socket.
+    socket.shutdown(SocketDirection.BOTH);
+    Expect.throws(
+        () => socket.writeFromSync(data), (e) => e is SocketException);
+    Expect.throws(
+        () => socket.readSync(data.length), (e) => e is SocketException);
+    socket.closeSync();
+
+    // Close the socket for reading, do a write, and see if we can get any
+    // response from the server (we shouldn't be able to).
+    socket = RawSynchronousSocket.connectSync(
+        LOOPBACK_IP_V4_STRING, serverInternetPort);
+    socket.shutdown(SocketDirection.RECEIVE);
+    socket.writeFromSync(data);
+    // Throws exception when the socket is closed for RECEIVE.
+    Expect.throws(
+        () => socket.readSync(data.length), (e) => e is SocketException);
+    Expect.isTrue(socket.available() == 0);
+    socket.closeSync();
+
+    // Close the socket for writing and try to do a write. This should cause an
+    // OSError to be throw as the pipe is closed for writing.
+    socket = RawSynchronousSocket.connectSync(
+        LOOPBACK_IP_V4_STRING, serverInternetPort);
+    socket.shutdown(SocketDirection.SEND);
+    Expect.throws(
+        () => socket.writeFromSync(data), (e) => e is SocketException);
+    socket.closeSync();
+  } catch (e, stack) {
+    print("Echo test failed in client.");
+    rethrow;
+  }
+  // Wait for the server to shutdown before finishing the test.
+  var result = await receivePort.first;
+  if (result != null) {
+    throw "Echo test failed in server!\nError: ${result[0]}\nStack trace:" +
+        " ${result[1]}";
+  }
+  asyncEnd();
+}
+
+Future testInvalidReadWriteOperations() {
+  asyncStart();
+  RawServerSocket.bind(InternetAddress.LOOPBACK_IP_V4, 0).then((server) {
+    server.listen((socket) {});
+    List<int> data = createTestData();
+    var socket =
+        RawSynchronousSocket.connectSync(LOOPBACK_IP_V4_STRING, server.port);
+
+    // Invalid writeFromSync invocations
+    Expect.throws(() => socket.writeFromSync(data, data.length + 1),
+        (e) => e is RangeError);
+    Expect.throws(() => socket.writeFromSync(data, 0, data.length + 1),
+        (e) => e is RangeError);
+    Expect.throws(
+        () => socket.writeFromSync(data, 1, 0), (e) => e is RangeError);
+    Expect.throws(
+        () => socket.writeFromSync(data, null), (e) => e is ArgumentError);
+
+    // Invalid readIntoSync invocations
+    List<int> buffer = new List<int>(10);
+    Expect.throws(() => socket.readIntoSync(buffer, buffer.length + 1),
+        (e) => e is RangeError);
+    Expect.throws(() => socket.readIntoSync(buffer, 0, buffer.length + 1),
+        (e) => e is RangeError);
+    Expect.throws(
+        () => socket.readIntoSync(buffer, 1, 0), (e) => e is RangeError);
+    Expect.throws(
+        () => socket.readIntoSync(buffer, null), (e) => e is ArgumentError);
+
+    // Invalid readSync invocation
+    Expect.throws(() => socket.readSync(-1), (e) => e is ArgumentError);
+
+    server.close();
+    socket.closeSync();
+    asyncEnd();
+  });
+}
+
+void testClosedError() {
+  asyncStart();
+  RawServerSocket.bind(InternetAddress.LOOPBACK_IP_V4, 0).then((server) {
+    server.listen((socket) {
+      socket.close();
+    });
+    var socket =
+        RawSynchronousSocket.connectSync(LOOPBACK_IP_V4_STRING, server.port);
+    server.close();
+    socket.closeSync();
+    Expect.throws(() => socket.remotePort, (e) => e is SocketException);
+    Expect.throws(() => socket.remoteAddress, (e) => e is SocketException);
+    asyncEnd();
+  });
+}
+
+main() async {
+  asyncStart();
+  testArguments();
+  // testInvalidConnect(); Long timeout for bad lookups, so disable for bots.
+  await testShutdown();
+  testSimpleConnect();
+  testServerListenAfterConnect();
+  await testSimpleReadWrite();
+  await testPartialRead();
+  await testPartialWrite();
+  testInvalidReadWriteOperations();
+  testClosedError();
+  asyncEnd();
+}