Add timeouts to HttpClient.

sdk/lib/io/http_impl.dart

Index: sdk/lib/io/http_impl.dart
diff --git a/sdk/lib/io/http_impl.dart b/sdk/lib/io/http_impl.dart
index b2d63b6a393a235fb017ba160bef1ed609b04a8e..1afbb43bdfdcab2087628ce3def5d9645a5ec65f 100644
--- a/sdk/lib/io/http_impl.dart
+++ b/sdk/lib/io/http_impl.dart
@@ -1071,6 +1071,7 @@ class _HttpClientConnection {
   StreamSubscription _subscription;
   final _HttpClient _httpClient;
   bool _dispose = false;
+  Timer _idleTimer;
   bool closed = false;
 
   Completer<_HttpIncoming> _nextResponseCompleter;
@@ -1285,6 +1286,22 @@ class _HttpClientConnection {
     return isSecure ? "ssh:$host:$port" : "$host:$port";
   }
 
+  void stopTimer() {
+    if (_idleTimer != null) {
+      _idleTimer.cancel();
+      _idleTimer = null;
+    }
+  }
+
+  void startTimer() {
+    assert(_idleTimer == null);
+    _idleTimer = new Timer(
+        _httpClient.idleTimeout,
+        () {
+          _idleTimer = null;
+          close();
+        });
+  }
 }
 
 class _ConnnectionInfo {
@@ -1296,7 +1313,6 @@ class _ConnnectionInfo {
 
 class _HttpClient implements HttpClient {
   // TODO(ajohnsen): Use eviction timeout.
-  static const int DEFAULT_EVICTION_TIMEOUT = 60000;
   bool _closing = false;
 
   final Map<String, Set<_HttpClientConnection>> _idleConnections
@@ -1308,6 +1324,21 @@ class _HttpClient implements HttpClient {
   Function _authenticate;
   Function _authenticateProxy;
   Function _findProxy = HttpClient.findProxyFromEnvironment;
+  Duration _idleTimeout = const Duration(seconds: 15);
+
+  Timer _noActiveTimer;
+
+  Duration get idleTimeout => _idleTimeout;
+
+  void set idleTimeout(Duration timeout) {
+    _idleTimeout = timeout;
+    var idle = _idleConnections.values.forEach(
+        (l) => l.forEach((c) {
+          // Reset timer. This is fine, as it's not happening often.
+          c.stopTimer();
+          c.startTimer();
+        }));
+  }
 
   Future<HttpClientRequest> open(String method,
                                  String host,
@@ -1485,15 +1516,17 @@ class _HttpClient implements HttpClient {
       connection.close();
       return;
     }
-    // TODO(ajohnsen): Listen for socket close events.
     if (!_idleConnections.containsKey(connection.key)) {
       _idleConnections[connection.key] = new LinkedHashSet();
     }
     _idleConnections[connection.key].add(connection);
+    connection.startTimer();
+    _updateTimers();
   }
 
   // Remove a closed connnection from the active set.
   void _connectionClosed(_HttpClientConnection connection) {
+    connection.stopTimer();
     _activeConnections.remove(connection);
     if (_idleConnections.containsKey(connection.key)) {
       _idleConnections[connection.key].remove(connection);
@@ -1501,6 +1534,24 @@ class _HttpClient implements HttpClient {
         _idleConnections.remove(connection.key);
       }
     }
+    _updateTimers();
+  }
+
+  void _updateTimers() {
+    if (_activeConnections.isEmpty) {
+      if (!_idleConnections.isEmpty && _noActiveTimer == null) {
+        _noActiveTimer = new Timer(const Duration(milliseconds: 100), () {
+          _noActiveTimer = null;
+          if (_activeConnections.isEmpty) {
+            close();
+            _closing = false;
+          }
+        });
+      }
+    } else if (_noActiveTimer != null) {
+      _noActiveTimer.cancel();
+      _noActiveTimer = null;
+    }
   }
 
   // Get a new _HttpClientConnection, either from the idle pool or created from
@@ -1523,7 +1574,9 @@ class _HttpClient implements HttpClient {
         if (_idleConnections[key].isEmpty) {
           _idleConnections.remove(key);
         }
+        connection.stopTimer();
         _activeConnections.add(connection);
+        _updateTimers();
         return new Future.value(new _ConnnectionInfo(connection, proxy));
       }
       return (isSecure && proxy.isDirect