SpringSource/spring-integration — pull request #407 by garyrussell (2012-04-19 17:45:38+00:00)
Title: INT-2519 Fix Memory Leak 2.0.x Backport

When using NIO, a Map of connections is maintained (keyed
by the SocketChannel) and used to manage registrations
for NIO events, timeouts etc.

When a connection is closed, the corresponding entry
should be removed from the map. The code to do this
is in AbstractConnectionFactory.processNioSelections().
However, if no socket timeout (soTimeout) has been set,
or it was explicitly set to 0, connections are not
removed from the map. This was because the timeout
logic and map cleanup is done in the same iteration
loop.

Now, if soTimeout is not set, the clean up loop
operates every nioHarvestInterval milliseconds
(default 2000), we don't want to run it on
every selector event.

In addition, it runs if the selectionCount is
zero - this might occur when a socket
is closed, when the selector.wakeup() is called.