runtime/bin/vmservice/vmservice_io.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.

library vmservice_io;

import 'dart:async';
import 'dart:collection';
import 'dart:convert';
import 'dart:io';
import 'dart:isolate';
import 'dart:_vmservice';

part 'loader.dart';
part 'server.dart';

// The TCP ip/port that the HTTP server listens on.
int _port;
String _ip;
// Should the HTTP server auto start?
bool _autoStart;

bool _isWindows = false;
var _signalWatch;
var _signalSubscription;

// HTTP server.
Server server;
Future<Server> serverFuture;

_lazyServerBoot() {
  if (server != null) {
    return;
  }
  // Lazily create service.
  var service = new VMService();
  // Lazily create server.
  server = new Server(service, _ip, _port);
}

Future cleanupCallback() async {
  // Cancel the sigquit subscription.
  if (_signalSubscription != null) {
    await _signalSubscription.cancel();
    _signalSubscription = null;
  }
  if (server != null) {
    try {
      await server.cleanup(true);
    } catch (e, st) {
      print("Error in vm-service shutdown: $e\n$st\n");
    }
  }
  // Call out to embedder's shutdown callback.
  _shutdown();
}

_clearFuture(_) {
  serverFuture = null;
}

_onSignal(ProcessSignal signal) {
  if (serverFuture != null) {
    // Still waiting.
    return;
  }
  _lazyServerBoot();
  // Toggle HTTP server.
  if (server.running) {
    serverFuture = server.shutdown(true).then(_clearFuture);
  } else {
    serverFuture = server.startup().then(_clearFuture);
  }
}

_registerSignalHandler() {
  if (_signalWatch == null) {
    // Cannot register for signals.
    return;
  }
  if (_isWindows) {
    // Cannot register for signals on Windows.
    return;
  }
  _signalSubscription = _signalWatch(ProcessSignal.SIGQUIT).listen(_onSignal);
}

main() {
  // Set embedder hooks.
  VMServiceEmbedderHooks.cleanup = cleanupCallback;
  if (_autoStart) {
    _lazyServerBoot();
    server.startup();
    // It's just here to push an event on the event loop so that we invoke the
    // scheduled microtasks.
    Timer.run(() {});
  }
  // TODO(johnmccutchan): Fixup service isolate shutdown in the general case.
  // See ServiceIsolate::KillServiceIsolate and ServiceIsolate::Shutdown.
  scriptLoadPort.handler = _processLoadRequest;
  // Register signal handler after a small delay to avoid stalling main
  // isolate startup.
  new Timer(shortDelay, _registerSignalHandler);
  return scriptLoadPort;
}

_shutdown() native "VMServiceIO_Shutdown";