Update charted to 0.4.8 and roll

packages/pool/lib/pool.dart

 // Copyright (c) 2014, 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 pool;
-
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:async/async.dart';
 import 'package:stack_trace/stack_trace.dart';
 
 /// Manages an abstract pool of resources with a limit on how many may be in use
 /// at once.
 ///
 /// When a resource is needed, the user should call [request]. When the returned
@@ skipping 41 matching lines @@
   /// The amount of time to wait before timing out the pending resources.
   final Duration _timeout;
 
   /// A [FutureGroup] that tracks all the `onRelease` callbacks for resources
   /// that have been marked releasable.
   ///
   /// This is `null` until [close] is called.
   FutureGroup _closeGroup;
 
   /// Whether [close] has been called.
-  bool get isClosed => _closeGroup != null;
+  bool get isClosed => _closeMemo.hasRun;
+
+  /// A future that completes once the pool is closed and all its outstanding
+  /// resources have been released.
+  ///
+  /// If any [PoolResource.allowRelease] callback throws an exception after the
+  /// pool is closed, this completes with that exception.
+  Future get done => _closeMemo.future;
 
   /// Creates a new pool with the given limit on how many resources may be
   /// allocated at once.
   ///
   /// If [timeout] is passed, then if that much time passes without any activity
   /// all pending [request] futures will throw a [TimeoutException]. This is
   /// intended to avoid deadlocks.
   Pool(this._maxAllocatedResources, {Duration timeout})
       : _timeout = timeout {
     if (timeout != null) {
@@ skipping 22 matching lines @@
       _requestedResources.add(completer);
       _resetTimer();
       return completer.future;
     }
   }
 
   /// Requests a resource for the duration of [callback], which may return a
   /// Future.
   ///
   /// The return value of [callback] is piped to the returned Future.
-  Future withResource(callback()) {
+  Future<T> withResource<T>(FutureOr<T> callback()) {
     if (isClosed) {
       throw new StateError(
           "withResource() may not be called on a closed Pool.");
     }
 
-    // TODO(nweiz): Use async/await when sdk#23497 is fixed.
-    return request().then((resource) {
-      return new Future.sync(callback).whenComplete(resource.release);
+    // We can't use async/await here because we need to start the request
+    // synchronously in case the pool is closed immediately afterwards. Async
+    // functions have an asynchronous gap between calling and running the body,
+    // and [close] could be called during that gap. See #3.
+    return request().then<Future<T>>((resource) {
+      return new Future<T>.sync(callback).whenComplete(resource.release);
     });
   }
 
   /// Closes the pool so that no more resources are requested.
   ///
   /// Existing resource requests remain unchanged.
   ///
   /// Any resources that are marked as releasable using
   /// [PoolResource.allowRelease] are released immediately. Once all resources
   /// have been released and any `onRelease` callbacks have completed, the
   /// returned future completes successfully. If any `onRelease` callback throws
   /// an error, the returned future completes with that error.
   ///
   /// This may be called more than once; it returns the same [Future] each time.
-  Future close() {
+  Future close() => _closeMemo.runOnce(() {
     if (_closeGroup != null) return _closeGroup.future;
 
     _resetTimer();
 
     _closeGroup = new FutureGroup();
     for (var callback in _onReleaseCallbacks) {
       _closeGroup.add(new Future.sync(callback));
     }
 
     _allocatedResources -= _onReleaseCallbacks.length;
     _onReleaseCallbacks.clear();
 
     if (_allocatedResources == 0) _closeGroup.close();
     return _closeGroup.future;
-  }
+  });
+  final _closeMemo = new AsyncMemoizer();
 
   /// If there are any pending requests, this will fire the oldest one.
   void _onResourceReleased() {
     _resetTimer();
 
     if (_requestedResources.isNotEmpty) {
       var pending = _requestedResources.removeFirst();
       pending.complete(new PoolResource._(this));
     } else {
       _allocatedResources--;
@@ skipping 24 matching lines @@
   ///
   /// Futures returned by [_runOnRelease] always complete in the order they were
   /// created, even if earlier [onRelease] callbacks take longer to run.
   Future<PoolResource> _runOnRelease(onRelease()) {
     new Future.sync(onRelease).then((value) {
       _onReleaseCompleters.removeFirst().complete(new PoolResource._(this));
     }).catchError((error, stackTrace) {
       _onReleaseCompleters.removeFirst().completeError(error, stackTrace);
     });
 
-    var completer = new Completer.sync();
+    var completer = new Completer<PoolResource>.sync();
     _onReleaseCompleters.add(completer);
     return completer.future;
   }
 
   /// A resource has been requested, allocated, or released.
   void _resetTimer() {
     if (_timer == null) return;
 
     if (_requestedResources.isEmpty) {
       _timer.cancel();
@@ skipping 52 matching lines @@
   /// produce additional information later on. For example, an isolate's task
   /// may be complete, but it could still emit asynchronous errors.
   void allowRelease(onRelease()) {
     if (_released) {
       throw new StateError("A PoolResource may only be released once.");
     }
     _released = true;
     _pool._onResourceReleaseAllowed(onRelease);
   }
 }