[
https://issues.apache.org/jira/browse/TINKERPOP-1978?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16522475#comment-16522475
]
ASF GitHub Bot commented on TINKERPOP-1978:
-------------------------------------------
Github user FlorianHockmann commented on a diff in the pull request:
https://github.com/apache/tinkerpop/pull/885#discussion_r197855449
--- Diff: gremlin-dotnet/src/Gremlin.Net/Driver/ConnectionPool.cs ---
@@ -45,19 +44,28 @@ public ConnectionPool(ConnectionFactory
connectionFactory)
public async Task<IConnection> GetAvailableConnectionAsync()
{
- Connection connection = null;
- lock (_connectionsLock)
- {
- if (!_connections.IsEmpty)
- _connections.TryTake(out connection);
- }
-
- if (connection == null)
+ if (!TryGetConnectionFromPool(out var connection))
connection = await
CreateNewConnectionAsync().ConfigureAwait(false);
return new ProxyConnection(connection, AddConnectionIfOpen);
}
+ private bool TryGetConnectionFromPool(out Connection connection)
+ {
+ while (true)
+ {
+ connection = null;
+ lock (_connectionsLock)
+ {
+ if (_connections.IsEmpty) return false;
+ _connections.TryTake(out connection);
+ }
+
+ if (connection.IsOpen) return true;
+ connection.Dispose();
--- End diff --
`_connections.TryTake(out connection)` removes the connection from the
collection. So, here it is already no longer part of `_connections`. That may
be a bit confusing as `_connections` doesn't contain all connections in the
pool but only those that are currently unused. That made this class a lot
easier to implement as no checks are needed of whether a connection is already
in use or not.
For reference: The
[`ConcurrentBag<T>.TryTake`](https://msdn.microsoft.com/en-us/library/dd381774(v=vs.110).aspx)
docs.
> Check for Websocket connection state when retrieved from Connection Pool
> missing
> --------------------------------------------------------------------------------
>
> Key: TINKERPOP-1978
> URL: https://issues.apache.org/jira/browse/TINKERPOP-1978
> Project: TinkerPop
> Issue Type: Bug
> Components: dotnet
> Affects Versions: 3.3.3
> Reporter: Jamilu Abubakar
> Assignee: Florian Hockmann
> Priority: Major
>
> When retrieving a connection from the connection pool there is no check to
> see what the current connection state of the websocket is before it is used.
> This means that if the websocket were to be closed because the server
> recycled or the connection was aborted by the server since it was last used
> and its Send method were to be called the following exception would be thrown:
> {quote}Error during execution ExecuteJObjectQueryAsync method. Exception:
> System.Net.Http.WinHttpException (0x80072EFF): The connection with the server
> was terminated abnormally
> at System.Net.WebSockets.WinHttpWebSocket.SendAsync(ArraySegment`1 buffer,
> WebSocketMessageType messageType, Boolean endOfMessage, CancellationToken
> cancellationToken)
> at System.Net.WebSockets.WebSocketHandle.SendAsync(ArraySegment`1 buffer,
> WebSocketMessageType messageType, Boolean endOfMessage, CancellationToken
> cancellationToken)
> at Gremlin.Net.Driver.WebSocketConnection.<SendMessageAsync>d__5.MoveNext()
> {quote}
>
> Please add check the Websocket state before use, handle exceptions due to
> closed or aborted connections and ideally have an extensible retry handler.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
