packages/flutter_tools/lib/src/commands/run.dart - mirrors/flutter - Git at Google

 // Copyright 2015 The Chromium Authors. 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 'package:path/path.dart' as path;

 import '../application_package.dart';
 import '../base/common.dart';
 import '../base/logger.dart';
 import '../base/utils.dart';
 import '../build_info.dart';
 import '../device.dart';
 import '../globals.dart';
 import '../observatory.dart';
 import '../runner/flutter_command.dart';
 import 'build_apk.dart';
 import 'install.dart';
 import 'trace.dart';

 abstract class RunCommandBase extends FlutterCommand {
   RunCommandBase() {
     addBuildModeFlags();

     argParser.addFlag('trace-startup',
         negatable: true,
         defaultsTo: false,
         help: 'Start tracing during startup.');
     argParser.addOption('route',
         help: 'Which route to load when running the app.');
     usesTargetOption();
   }

   bool get traceStartup => argResults['trace-startup'];
   String get target => argResults['target'];
   String get route => argResults['route'];
 }

 class RunCommand extends RunCommandBase {
   @override
   final String name = 'run';

   @override
   final String description = 'Run your Flutter app on an attached device.';

   RunCommand() {
     argParser.addFlag('full-restart',
         defaultsTo: true,
         help: 'Stop any currently running application process before running the app.');
     argParser.addFlag('start-paused',
         defaultsTo: false,
         negatable: false,
         help: 'Start in a paused mode and wait for a debugger to connect.');
     argParser.addOption('debug-port',
         help: 'Listen to the given port for a debug connection (defaults to $kDefaultObservatoryPort).');
     usesPubOption();

     // A temporary, hidden flag to experiment with a different run style.
     // TODO(devoncarew): Remove this.
     argParser.addFlag('resident',
         defaultsTo: false,
         negatable: false,
         hide: true,
         help: 'Stay resident after running the app.');

     // Hidden option to enable a benchmarking mode. This will run the given
     // application, measure the startup time and the app restart time, write the
     // results out to 'refresh_benchmark.json', and exit. This flag is intended
     // for use in generating automated flutter benchmarks.
     argParser.addFlag('benchmark', negatable: false, hide: true);
   }

   @override
   bool get requiresDevice => true;

   @override
   String get usagePath {
     Device device = deviceForCommand;

     if (device == null)
       return name;

     // Return 'run/ios'.
     return '$name/${getNameForTargetPlatform(device.platform)}';
   }

   @override
   Future<int> runInProject() async {
     int debugPort;

     if (argResults['debug-port'] != null) {
       try {
         debugPort = int.parse(argResults['debug-port']);
       } catch (error) {
         printError('Invalid port for `--debug-port`: $error');
         return 1;
       }
     }

     DebuggingOptions options;

     if (getBuildMode() != BuildMode.debug) {
       options = new DebuggingOptions.disabled(getBuildMode());
     } else {
       options = new DebuggingOptions.enabled(
         getBuildMode(),
         startPaused: argResults['start-paused'],
         observatoryPort: debugPort
       );
     }

     if (argResults['resident']) {
       _RunAndStayResident runner = new _RunAndStayResident(
         deviceForCommand,
         target: target,
         debuggingOptions: options,
         buildMode: getBuildMode()
       );

       return runner.run(traceStartup: traceStartup, benchmark: argResults['benchmark']);
     } else {
       return startApp(
         deviceForCommand,
         target: target,
         stop: argResults['full-restart'],
         install: true,
         debuggingOptions: options,
         traceStartup: traceStartup,
         benchmark: argResults['benchmark'],
         route: route,
         buildMode: getBuildMode()
       );
     }
   }
 }

 Future<int> startApp(
   Device device, {
   String target,
   bool stop: true,
   bool install: true,
   DebuggingOptions debuggingOptions,
   bool traceStartup: false,
   bool benchmark: false,
   String route,
   BuildMode buildMode: BuildMode.debug
 }) async {
   String mainPath = findMainDartFile(target);
   if (!FileSystemEntity.isFileSync(mainPath)) {
     String message = 'Tried to run $mainPath, but that file does not exist.';
     if (target == null)
       message += '\nConsider using the -t option to specify the Dart file to start.';
     printError(message);
     return 1;
   }

   ApplicationPackage package = getApplicationPackageForPlatform(device.platform);

   if (package == null) {
     String message = 'No application found for ${device.platform}.';
     String hint = _getMissingPackageHintForPlatform(device.platform);
     if (hint != null)
       message += '\n$hint';
     printError(message);
     return 1;
   }

   Stopwatch stopwatch = new Stopwatch()..start();

   // TODO(devoncarew): We shouldn't have to do type checks here.
   if (install && device is AndroidDevice) {
     printTrace('Running build command.');

     int result = await buildApk(
       device.platform,
       target: target,
       buildMode: buildMode
     );

     if (result != 0)
       return result;
   }

   // TODO(devoncarew): Move this into the device.startApp() impls. They should
   // wait on the stop command to complete before (re-)starting the app. We could
   // plumb a Future through the start command from here, but that seems a little
   // messy.
   if (stop) {
     if (package != null) {
       printTrace("Stopping app '${package.name}' on ${device.name}.");
       // We don't wait for the stop command to complete.
       device.stopApp(package);
     }
   }

   // Allow any stop commands from above to start work.
   await new Future<Duration>.delayed(Duration.ZERO);

   // TODO(devoncarew): This fails for ios devices - we haven't built yet.
   if (install && device is AndroidDevice) {
     printStatus('Installing $package to $device...');

     if (!(installApp(device, package)))
       return 1;
   }

   Map<String, dynamic> platformArgs = <String, dynamic>{};

   if (traceStartup != null)
     platformArgs['trace-startup'] = traceStartup;

   printStatus('Running ${_getDisplayPath(mainPath)} on ${device.name}...');

   LaunchResult result = await device.startApp(
     package,
     buildMode,
     mainPath: mainPath,
     route: route,
     debuggingOptions: debuggingOptions,
     platformArgs: platformArgs
   );

   stopwatch.stop();

   if (!result.started) {
     printError('Error running application on ${device.name}.');
   } else if (traceStartup) {
     try {
       Observatory observatory = await Observatory.connect(result.observatoryPort);
       await _downloadStartupTrace(observatory);
     } catch (error) {
       printError('Error connecting to observatory: $error');
       return 1;
     }
   }

   if (benchmark)
     _writeBenchmark(stopwatch);

   return result.started ? 0 : 2;
 }

 /// Given the value of the --target option, return the path of the Dart file
 /// where the app's main function should be.
 String findMainDartFile([String target]) {
   if (target == null)
     target = '';
   String targetPath = path.absolute(target);
   if (FileSystemEntity.isDirectorySync(targetPath))
     return path.join(targetPath, 'lib', 'main.dart');
   else
     return targetPath;
 }

 String _getMissingPackageHintForPlatform(TargetPlatform platform) {
   switch (platform) {
     case TargetPlatform.android_arm:
     case TargetPlatform.android_x64:
       return 'Is your project missing an android/AndroidManifest.xml?';
     case TargetPlatform.ios:
       return 'Is your project missing an ios/Info.plist?';
     default:
       return null;
   }
 }

 /// Return a relative path if [fullPath] is contained by the cwd, else return an
 /// absolute path.
 String _getDisplayPath(String fullPath) {
   String cwd = Directory.current.path + Platform.pathSeparator;
   return fullPath.startsWith(cwd) ?  fullPath.substring(cwd.length) : fullPath;
 }

 class _RunAndStayResident {
   _RunAndStayResident(
     this.device, {
     this.target,
     this.debuggingOptions,
     this.buildMode : BuildMode.debug
   });

   final Device device;
   final String target;
   final DebuggingOptions debuggingOptions;
   final BuildMode buildMode;

   Completer<int> _exitCompleter;
   StreamSubscription<String> _loggingSubscription;

   Observatory observatory;
   String _isolateId;

   /// Start the app and keep the process running during its lifetime.
   Future<int> run({ bool traceStartup: false, bool benchmark: false }) async {
     String mainPath = findMainDartFile(target);
     if (!FileSystemEntity.isFileSync(mainPath)) {
       String message = 'Tried to run $mainPath, but that file does not exist.';
       if (target == null)
         message += '\nConsider using the -t option to specify the Dart file to start.';
       printError(message);
       return 1;
     }

     ApplicationPackage package = getApplicationPackageForPlatform(device.platform);

     if (package == null) {
       String message = 'No application found for ${device.platform}.';
       String hint = _getMissingPackageHintForPlatform(device.platform);
       if (hint != null)
         message += '\n$hint';
       printError(message);
       return 1;
     }

     Stopwatch stopwatch = new Stopwatch()..start();

     // TODO(devoncarew): We shouldn't have to do type checks here.
     if (device is AndroidDevice) {
       printTrace('Running build command.');

       int result = await buildApk(
         device.platform,
         target: target,
         buildMode: buildMode
       );

       if (result != 0)
         return result;
     }

     // TODO(devoncarew): Move this into the device.startApp() impls.
     if (package != null) {
       printTrace("Stopping app '${package.name}' on ${device.name}.");
       // We don't wait for the stop command to complete.
       device.stopApp(package);
     }

     // Allow any stop commands from above to start work.
     await new Future<Duration>.delayed(Duration.ZERO);

     // TODO(devoncarew): This fails for ios devices - we haven't built yet.
     if (device is AndroidDevice) {
       printTrace('Running install command.');
       if (!(installApp(device, package)))
         return 1;
     }

     Map<String, dynamic> platformArgs;
     if (traceStartup != null)
       platformArgs = <String, dynamic>{ 'trace-startup': traceStartup };

     printStatus('Running ${_getDisplayPath(mainPath)} on ${device.name}...');

     _loggingSubscription = device.logReader.logLines.listen((String line) {
       if (!line.contains('Observatory listening on http') && !line.contains('Diagnostic server listening on http'))
         printStatus(line);
     });

     LaunchResult result = await device.startApp(
       package,
       buildMode,
       mainPath: mainPath,
       debuggingOptions: debuggingOptions,
       platformArgs: platformArgs
     );

     if (!result.started) {
       printError('Error running application on ${device.name}.');
       await _loggingSubscription.cancel();
       return 2;
     }

     stopwatch.stop();

     _exitCompleter = new Completer<int>();

     // Connect to observatory.
     if (debuggingOptions.debuggingEnabled) {
       observatory = await Observatory.connect(result.observatoryPort);
       printTrace('Connected to observatory port: ${result.observatoryPort}.');

       observatory.onIsolateEvent.listen((Event event) {
         if (event['isolate'] != null)
           _isolateId = event['isolate']['id'];
       });
       observatory.streamListen('Isolate');

       // Listen for observatory connection close.
       observatory.done.whenComplete(() {
         _handleExit();
       });

       observatory.getVM().then((VM vm) {
         if (vm.isolates.isNotEmpty)
           _isolateId = vm.isolates.first['id'];
       });
     }

     printStatus('Application running.');

     if (observatory != null && traceStartup) {
       printStatus('Downloading startup trace info...');

       await _downloadStartupTrace(observatory);

       _handleExit();
     } else {
       _printHelp();

       terminal.singleCharMode = true;

       terminal.onCharInput.listen((String code) {
         String lower = code.toLowerCase();

         if (lower == 'h' || code == AnsiTerminal.KEY_F1) {
           // F1, help
           _printHelp();
         } else if (lower == 'r' || code == AnsiTerminal.KEY_F5) {
           // F5, refresh
           _handleRefresh();
         } else if (lower == 'q' || code == AnsiTerminal.KEY_F10) {
           // F10, exit
           _handleExit();
         }
       });

       ProcessSignal.SIGINT.watch().listen((ProcessSignal signal) {
         _handleExit();
       });
       ProcessSignal.SIGTERM.watch().listen((ProcessSignal signal) {
         _handleExit();
       });
     }

     if (benchmark) {
       _writeBenchmark(stopwatch);
       new Future<Null>.delayed(new Duration(seconds: 2)).then((_) {
         _handleExit();
       });
     }

     return _exitCompleter.future.then((int exitCode) async {
       if (observatory != null && !observatory.isClosed && _isolateId != null) {
         observatory.flutterExit(_isolateId);

         // WebSockets do not have a flush() method.
         await new Future<Null>.delayed(new Duration(milliseconds: 100));
       }

       return exitCode;
     });
   }

   void _printHelp() {
     printStatus('Type "h" or F1 for help, "r" or F5 to restart the app, and "q", F10, or ctrl-c to quit.');
   }

   void _handleRefresh() {
     if (observatory == null) {
       printError('Debugging is not enabled.');
     } else {
       printStatus('Re-starting application...');

       observatory.isolateReload(_isolateId).catchError((dynamic error) {
         printError('Error restarting app: $error');
       });
     }
   }

   void _handleExit() {
     terminal.singleCharMode = false;

     if (!_exitCompleter.isCompleted) {
       _loggingSubscription?.cancel();
       printStatus('Application finished.');
       _exitCompleter.complete(0);
     }
   }
 }

 Future<Null> _downloadStartupTrace(Observatory observatory) async {
   Tracing tracing = new Tracing(observatory);

   Map<String, dynamic> timeline = await tracing.stopTracingAndDownloadTimeline(
     waitForFirstFrame: true
   );

   int extractInstantEventTimestamp(String eventName) {
     List<Map<String, dynamic>> events = timeline['traceEvents'];
     Map<String, dynamic> event = events.firstWhere(
       (Map<String, dynamic> event) => event['name'] == eventName, orElse: () => null
     );
     return event == null ? null : event['ts'];
   }

   int engineEnterTimestampMicros = extractInstantEventTimestamp(kFlutterEngineMainEnterEventName);
   int frameworkInitTimestampMicros = extractInstantEventTimestamp(kFrameworkInitEventName);
   int firstFrameTimestampMicros = extractInstantEventTimestamp(kFirstUsefulFrameEventName);

   if (engineEnterTimestampMicros == null) {
     printError('Engine start event is missing in the timeline. Cannot compute startup time.');
     return null;
   }

   if (firstFrameTimestampMicros == null) {
     printError('First frame event is missing in the timeline. Cannot compute startup time.');
     return null;
   }

   File traceInfoFile = new File('build/start_up_info.json');
   int timeToFirstFrameMicros = firstFrameTimestampMicros - engineEnterTimestampMicros;
   Map<String, dynamic> traceInfo = <String, dynamic>{
     'engineEnterTimestampMicros': engineEnterTimestampMicros,
     'timeToFirstFrameMicros': timeToFirstFrameMicros,
   };

   if (frameworkInitTimestampMicros != null) {
     traceInfo['timeToFrameworkInitMicros'] = frameworkInitTimestampMicros - engineEnterTimestampMicros;
     traceInfo['timeAfterFrameworkInitMicros'] = firstFrameTimestampMicros - frameworkInitTimestampMicros;
   }

   traceInfoFile.writeAsStringSync(toPrettyJson(traceInfo));

   printStatus('Time to first frame: ${timeToFirstFrameMicros ~/ 1000}ms.');
   printStatus('Saved startup trace info in ${traceInfoFile.path}.');
 }

 void _writeBenchmark(Stopwatch stopwatch) {
   final String benchmarkOut = 'refresh_benchmark.json';
   Map<String, dynamic> data = <String, dynamic>{
     'time': stopwatch.elapsedMilliseconds
   };
   new File(benchmarkOut).writeAsStringSync(toPrettyJson(data));
   printStatus('Run benchmark written to $benchmarkOut ($data).');
 }
	// Copyright 2015 The Chromium Authors. 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 'package:path/path.dart' as path;

	import '../application_package.dart';
	import '../base/common.dart';
	import '../base/logger.dart';
	import '../base/utils.dart';
	import '../build_info.dart';
	import '../device.dart';
	import '../globals.dart';
	import '../observatory.dart';
	import '../runner/flutter_command.dart';
	import 'build_apk.dart';
	import 'install.dart';
	import 'trace.dart';

	abstract class RunCommandBase extends FlutterCommand {
	RunCommandBase() {
	addBuildModeFlags();

	argParser.addFlag('trace-startup',
	negatable: true,
	defaultsTo: false,
	help: 'Start tracing during startup.');
	argParser.addOption('route',
	help: 'Which route to load when running the app.');
	usesTargetOption();
	}

	bool get traceStartup => argResults['trace-startup'];
	String get target => argResults['target'];
	String get route => argResults['route'];
	}

	class RunCommand extends RunCommandBase {
	@override
	final String name = 'run';

	@override
	final String description = 'Run your Flutter app on an attached device.';

	RunCommand() {
	argParser.addFlag('full-restart',
	defaultsTo: true,
	help: 'Stop any currently running application process before running the app.');
	argParser.addFlag('start-paused',
	defaultsTo: false,
	negatable: false,
	help: 'Start in a paused mode and wait for a debugger to connect.');
	argParser.addOption('debug-port',
	help: 'Listen to the given port for a debug connection (defaults to $kDefaultObservatoryPort).');
	usesPubOption();

	// A temporary, hidden flag to experiment with a different run style.
	// TODO(devoncarew): Remove this.
	argParser.addFlag('resident',
	defaultsTo: false,
	negatable: false,
	hide: true,
	help: 'Stay resident after running the app.');

	// Hidden option to enable a benchmarking mode. This will run the given
	// application, measure the startup time and the app restart time, write the
	// results out to 'refresh_benchmark.json', and exit. This flag is intended
	// for use in generating automated flutter benchmarks.
	argParser.addFlag('benchmark', negatable: false, hide: true);
	}

	@override
	bool get requiresDevice => true;

	@override
	String get usagePath {
	Device device = deviceForCommand;

	if (device == null)
	return name;

	// Return 'run/ios'.
	return '$name/${getNameForTargetPlatform(device.platform)}';
	}

	@override
	Future<int> runInProject() async {
	int debugPort;

	if (argResults['debug-port'] != null) {
	try {
	debugPort = int.parse(argResults['debug-port']);
	} catch (error) {
	printError('Invalid port for `--debug-port`: $error');
	return 1;
	}
	}

	DebuggingOptions options;

	if (getBuildMode() != BuildMode.debug) {
	options = new DebuggingOptions.disabled(getBuildMode());
	} else {
	options = new DebuggingOptions.enabled(
	getBuildMode(),
	startPaused: argResults['start-paused'],
	observatoryPort: debugPort
	);
	}

	if (argResults['resident']) {
	_RunAndStayResident runner = new _RunAndStayResident(
	deviceForCommand,
	target: target,
	debuggingOptions: options,
	buildMode: getBuildMode()
	);

	return runner.run(traceStartup: traceStartup, benchmark: argResults['benchmark']);
	} else {
	return startApp(
	deviceForCommand,
	target: target,
	stop: argResults['full-restart'],
	install: true,
	debuggingOptions: options,
	traceStartup: traceStartup,
	benchmark: argResults['benchmark'],
	route: route,
	buildMode: getBuildMode()
	);
	}
	}
	}

	Future<int> startApp(
	Device device, {
	String target,
	bool stop: true,
	bool install: true,
	DebuggingOptions debuggingOptions,
	bool traceStartup: false,
	bool benchmark: false,
	String route,
	BuildMode buildMode: BuildMode.debug
	}) async {
	String mainPath = findMainDartFile(target);
	if (!FileSystemEntity.isFileSync(mainPath)) {
	String message = 'Tried to run $mainPath, but that file does not exist.';
	if (target == null)
	message += '\nConsider using the -t option to specify the Dart file to start.';
	printError(message);
	return 1;
	}

	ApplicationPackage package = getApplicationPackageForPlatform(device.platform);

	if (package == null) {
	String message = 'No application found for ${device.platform}.';
	String hint = _getMissingPackageHintForPlatform(device.platform);
	if (hint != null)
	message += '\n$hint';
	printError(message);
	return 1;
	}

	Stopwatch stopwatch = new Stopwatch()..start();

	// TODO(devoncarew): We shouldn't have to do type checks here.
	if (install && device is AndroidDevice) {
	printTrace('Running build command.');

	int result = await buildApk(
	device.platform,
	target: target,
	buildMode: buildMode
	);

	if (result != 0)
	return result;
	}

	// TODO(devoncarew): Move this into the device.startApp() impls. They should
	// wait on the stop command to complete before (re-)starting the app. We could
	// plumb a Future through the start command from here, but that seems a little
	// messy.
	if (stop) {
	if (package != null) {
	printTrace("Stopping app '${package.name}' on ${device.name}.");
	// We don't wait for the stop command to complete.
	device.stopApp(package);
	}
	}

	// Allow any stop commands from above to start work.
	await new Future<Duration>.delayed(Duration.ZERO);

	// TODO(devoncarew): This fails for ios devices - we haven't built yet.
	if (install && device is AndroidDevice) {
	printStatus('Installing $package to $device...');

	if (!(installApp(device, package)))
	return 1;
	}

	Map<String, dynamic> platformArgs = <String, dynamic>{};

	if (traceStartup != null)
	platformArgs['trace-startup'] = traceStartup;

	printStatus('Running ${_getDisplayPath(mainPath)} on ${device.name}...');

	LaunchResult result = await device.startApp(
	package,
	buildMode,
	mainPath: mainPath,
	route: route,
	debuggingOptions: debuggingOptions,
	platformArgs: platformArgs
	);

	stopwatch.stop();

	if (!result.started) {
	printError('Error running application on ${device.name}.');
	} else if (traceStartup) {
	try {
	Observatory observatory = await Observatory.connect(result.observatoryPort);
	await _downloadStartupTrace(observatory);
	} catch (error) {
	printError('Error connecting to observatory: $error');
	return 1;
	}
	}

	if (benchmark)
	_writeBenchmark(stopwatch);

	return result.started ? 0 : 2;
	}

	/// Given the value of the --target option, return the path of the Dart file
	/// where the app's main function should be.
	String findMainDartFile([String target]) {
	if (target == null)
	target = '';
	String targetPath = path.absolute(target);
	if (FileSystemEntity.isDirectorySync(targetPath))
	return path.join(targetPath, 'lib', 'main.dart');
	else
	return targetPath;
	}

	String _getMissingPackageHintForPlatform(TargetPlatform platform) {
	switch (platform) {
	case TargetPlatform.android_arm:
	case TargetPlatform.android_x64:
	return 'Is your project missing an android/AndroidManifest.xml?';
	case TargetPlatform.ios:
	return 'Is your project missing an ios/Info.plist?';
	default:
	return null;
	}
	}

	/// Return a relative path if [fullPath] is contained by the cwd, else return an
	/// absolute path.
	String _getDisplayPath(String fullPath) {
	String cwd = Directory.current.path + Platform.pathSeparator;
	return fullPath.startsWith(cwd) ? fullPath.substring(cwd.length) : fullPath;
	}

	class _RunAndStayResident {
	_RunAndStayResident(
	this.device, {
	this.target,
	this.debuggingOptions,
	this.buildMode : BuildMode.debug
	});

	final Device device;
	final String target;
	final DebuggingOptions debuggingOptions;
	final BuildMode buildMode;

	Completer<int> _exitCompleter;
	StreamSubscription<String> _loggingSubscription;

	Observatory observatory;
	String _isolateId;

	/// Start the app and keep the process running during its lifetime.
	Future<int> run({ bool traceStartup: false, bool benchmark: false }) async {
	String mainPath = findMainDartFile(target);
	if (!FileSystemEntity.isFileSync(mainPath)) {
	String message = 'Tried to run $mainPath, but that file does not exist.';
	if (target == null)
	message += '\nConsider using the -t option to specify the Dart file to start.';
	printError(message);
	return 1;
	}

	ApplicationPackage package = getApplicationPackageForPlatform(device.platform);

	if (package == null) {
	String message = 'No application found for ${device.platform}.';
	String hint = _getMissingPackageHintForPlatform(device.platform);
	if (hint != null)
	message += '\n$hint';
	printError(message);
	return 1;
	}

	Stopwatch stopwatch = new Stopwatch()..start();

	// TODO(devoncarew): We shouldn't have to do type checks here.
	if (device is AndroidDevice) {
	printTrace('Running build command.');

	int result = await buildApk(
	device.platform,
	target: target,
	buildMode: buildMode
	);

	if (result != 0)
	return result;
	}

	// TODO(devoncarew): Move this into the device.startApp() impls.
	if (package != null) {
	printTrace("Stopping app '${package.name}' on ${device.name}.");
	// We don't wait for the stop command to complete.
	device.stopApp(package);
	}

	// Allow any stop commands from above to start work.
	await new Future<Duration>.delayed(Duration.ZERO);

	// TODO(devoncarew): This fails for ios devices - we haven't built yet.
	if (device is AndroidDevice) {
	printTrace('Running install command.');
	if (!(installApp(device, package)))
	return 1;
	}

	Map<String, dynamic> platformArgs;
	if (traceStartup != null)
	platformArgs = <String, dynamic>{ 'trace-startup': traceStartup };

	printStatus('Running ${_getDisplayPath(mainPath)} on ${device.name}...');

	_loggingSubscription = device.logReader.logLines.listen((String line) {
	if (!line.contains('Observatory listening on http') && !line.contains('Diagnostic server listening on http'))
	printStatus(line);
	});

	LaunchResult result = await device.startApp(
	package,
	buildMode,
	mainPath: mainPath,
	debuggingOptions: debuggingOptions,
	platformArgs: platformArgs
	);

	if (!result.started) {
	printError('Error running application on ${device.name}.');
	await _loggingSubscription.cancel();
	return 2;
	}

	stopwatch.stop();

	_exitCompleter = new Completer<int>();

	// Connect to observatory.
	if (debuggingOptions.debuggingEnabled) {
	observatory = await Observatory.connect(result.observatoryPort);
	printTrace('Connected to observatory port: ${result.observatoryPort}.');

	observatory.onIsolateEvent.listen((Event event) {
	if (event['isolate'] != null)
	_isolateId = event['isolate']['id'];
	});
	observatory.streamListen('Isolate');

	// Listen for observatory connection close.
	observatory.done.whenComplete(() {
	_handleExit();
	});

	observatory.getVM().then((VM vm) {
	if (vm.isolates.isNotEmpty)
	_isolateId = vm.isolates.first['id'];
	});
	}

	printStatus('Application running.');

	if (observatory != null && traceStartup) {
	printStatus('Downloading startup trace info...');

	await _downloadStartupTrace(observatory);

	_handleExit();
	} else {
	_printHelp();

	terminal.singleCharMode = true;

	terminal.onCharInput.listen((String code) {
	String lower = code.toLowerCase();

	if (lower == 'h' \|\| code == AnsiTerminal.KEY_F1) {
	// F1, help
	_printHelp();
	} else if (lower == 'r' \|\| code == AnsiTerminal.KEY_F5) {
	// F5, refresh
	_handleRefresh();
	} else if (lower == 'q' \|\| code == AnsiTerminal.KEY_F10) {
	// F10, exit
	_handleExit();
	}
	});

	ProcessSignal.SIGINT.watch().listen((ProcessSignal signal) {
	_handleExit();
	});
	ProcessSignal.SIGTERM.watch().listen((ProcessSignal signal) {
	_handleExit();
	});
	}

	if (benchmark) {
	_writeBenchmark(stopwatch);
	new Future<Null>.delayed(new Duration(seconds: 2)).then((_) {
	_handleExit();
	});
	}

	return _exitCompleter.future.then((int exitCode) async {
	if (observatory != null && !observatory.isClosed && _isolateId != null) {
	observatory.flutterExit(_isolateId);

	// WebSockets do not have a flush() method.
	await new Future<Null>.delayed(new Duration(milliseconds: 100));
	}

	return exitCode;
	});
	}

	void _printHelp() {
	printStatus('Type "h" or F1 for help, "r" or F5 to restart the app, and "q", F10, or ctrl-c to quit.');
	}

	void _handleRefresh() {
	if (observatory == null) {
	printError('Debugging is not enabled.');
	} else {
	printStatus('Re-starting application...');

	observatory.isolateReload(_isolateId).catchError((dynamic error) {
	printError('Error restarting app: $error');
	});
	}
	}

	void _handleExit() {
	terminal.singleCharMode = false;

	if (!_exitCompleter.isCompleted) {
	_loggingSubscription?.cancel();
	printStatus('Application finished.');
	_exitCompleter.complete(0);
	}
	}
	}

	Future<Null> _downloadStartupTrace(Observatory observatory) async {
	Tracing tracing = new Tracing(observatory);

	Map<String, dynamic> timeline = await tracing.stopTracingAndDownloadTimeline(
	waitForFirstFrame: true
	);

	int extractInstantEventTimestamp(String eventName) {
	List<Map<String, dynamic>> events = timeline['traceEvents'];
	Map<String, dynamic> event = events.firstWhere(
	(Map<String, dynamic> event) => event['name'] == eventName, orElse: () => null
	);
	return event == null ? null : event['ts'];
	}

	int engineEnterTimestampMicros = extractInstantEventTimestamp(kFlutterEngineMainEnterEventName);
	int frameworkInitTimestampMicros = extractInstantEventTimestamp(kFrameworkInitEventName);
	int firstFrameTimestampMicros = extractInstantEventTimestamp(kFirstUsefulFrameEventName);

	if (engineEnterTimestampMicros == null) {
	printError('Engine start event is missing in the timeline. Cannot compute startup time.');
	return null;
	}

	if (firstFrameTimestampMicros == null) {
	printError('First frame event is missing in the timeline. Cannot compute startup time.');
	return null;
	}

	File traceInfoFile = new File('build/start_up_info.json');
	int timeToFirstFrameMicros = firstFrameTimestampMicros - engineEnterTimestampMicros;
	Map<String, dynamic> traceInfo = <String, dynamic>{
	'engineEnterTimestampMicros': engineEnterTimestampMicros,
	'timeToFirstFrameMicros': timeToFirstFrameMicros,
	};

	if (frameworkInitTimestampMicros != null) {
	traceInfo['timeToFrameworkInitMicros'] = frameworkInitTimestampMicros - engineEnterTimestampMicros;
	traceInfo['timeAfterFrameworkInitMicros'] = firstFrameTimestampMicros - frameworkInitTimestampMicros;
	}

	traceInfoFile.writeAsStringSync(toPrettyJson(traceInfo));

	printStatus('Time to first frame: ${timeToFirstFrameMicros ~/ 1000}ms.');
	printStatus('Saved startup trace info in ${traceInfoFile.path}.');
	}

	void _writeBenchmark(Stopwatch stopwatch) {
	final String benchmarkOut = 'refresh_benchmark.json';
	Map<String, dynamic> data = <String, dynamic>{
	'time': stopwatch.elapsedMilliseconds
	};
	new File(benchmarkOut).writeAsStringSync(toPrettyJson(data));
	printStatus('Run benchmark written to $benchmarkOut ($data).');
	}