NioEventLoop closes channel even if channel is not registered

Motivation:
If a channel is deregistered from an NioEventLoop the associated SelectionKey is cancelled. If the NioEventLoop has yet to process a pending event as a result of that SelectionKey then the NioEventLoop will see the SelecitonKey is invalid and close the channel. The NioEventLoop should not close a channel if it is not registered with that NioEventLoop.

Modifications:
- NioEventLoop.processSelectedKeys should check that the channel is still registered to itself before closing the channel

Result:
NioEventLoop doesn't close a channel that is no longer registered to it when the SelectionKey is invalid
Fixes https://github.com/netty/netty/issues/5125
This commit is contained in:
Scott Mitchell 2016-04-14 10:42:13 -07:00
parent f60698a538
commit 04e33fd2d8

View File

@ -17,6 +17,7 @@ package io.netty.channel.nio;
import io.netty.channel.Channel;
import io.netty.channel.ChannelException;
import io.netty.channel.EventLoop;
import io.netty.channel.EventLoopException;
import io.netty.channel.SelectStrategy;
import io.netty.channel.SingleThreadEventLoop;
@ -511,9 +512,25 @@ public final class NioEventLoop extends SingleThreadEventLoop {
}
}
private static void processSelectedKey(SelectionKey k, AbstractNioChannel ch) {
private void processSelectedKey(SelectionKey k, AbstractNioChannel ch) {
final AbstractNioChannel.NioUnsafe unsafe = ch.unsafe();
if (!k.isValid()) {
final EventLoop eventLoop;
try {
eventLoop = ch.eventLoop();
} catch (Throwable ignored) {
// If the channel implementation throws an exception because there is no event loop, we ignore this
// because we are only trying to determine if ch is registered to this event loop and thus has authority
// to close ch.
return;
}
// Only close ch if ch is still registerd to this EventLoop. ch could have deregistered from the event loop
// and thus the SelectionKey could be cancelled as part of the deregistration process, but the channel is
// still healthy and should not be closed.
// See https://github.com/netty/netty/issues/5125
if (eventLoop != this || eventLoop == null) {
return;
}
// close the channel if the key is not valid anymore
unsafe.close(unsafe.voidPromise());
return;