Thomas Wolf created DIRMINA-1169:
------------------------------------
Summary: BindException on Java >= 11 due to race condition in
AbstractPollingIoAcceptor
Key: DIRMINA-1169
URL: https://issues.apache.org/jira/browse/DIRMINA-1169
Project: MINA
Issue Type: Bug
Affects Versions: 2.2.1, 2.0.23, 2.1.6
Reporter: Thomas Wolf
See also SSHD-1256.
The main acceptor loop does basically (somewhat simplified):
{code:java}
while (selectable) {
registerHandles(); // Process registration queue: add new sockets (from
bind()) to the selector with OP_ACCEPT, fulfills their open futures
int selected = select();
if (/* nothing to do */) {
break; // and end the thread; higher layers will create a new one if needed
}
if (selected > 0) {
processHandles(selectedHandles()); // Handle and hand off new connections
}
unregisterHandles(); // Process cancel queue: cancel SelectionKey, close
ServerSocketChannel, fulfill the cancel future
}
{code}
With Java 11, unbinding a {{ServerSocketChannel}} changed:
* [JDK-8214430|https://bugs.openjdk.org/browse/JDK-8214430]
* [Java 11 Release
Notes|https://www.oracle.com/java/technologies/javase/11-relnote-issues.html#JDK-8198562]
Essentially the unbind gives up the socket only at the next {{select()}} call.
This causes two problems in Apache MINA's acceptor:
* The unbind future is set "done" before the socket is actually released.
* If a new binding for one of the unbound sockets is registered before that
{{select()}} has been done, {{registerHandles()}} gets a {{BindException}}
("address already in use").
So for Java >= 11, the code must ensure that there is a {{select()}} between
processing unbindings and processing new bindings, and the unbind futures must
be set "done" only after that {{select()}}.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
