andreacavalli/netty5
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Add workaround for epoll bug that cause 100% cpu usage also in the NioClientSocketPipelineSink

Browse Source
This commit is contained in:
norman 2012-08-27 11:12:15 +02:00
parent db1a72c02e
commit 292a186d16
1 changed files with 71 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

72
src/main/java/org/jboss/netty/channel/socket/nio/NioClientSocketPipelineSink.java
View File

@ -21,6 +21,7 @@ import java.io.IOException;
import java.net.ConnectException;
import java.net.SocketAddress;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectableChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.util.Iterator;
@ -236,13 +237,44 @@ class NioClientSocketPipelineSink extends AbstractNioChannelSink {
public void run() {
boolean shutdown = false;
int selectReturnsImmediately = 0;
Selector selector = this.selector;
long lastConnectTimeoutCheckTimeNanos = System.nanoTime();
// use 80% of the timeout for measure
long minSelectTimeout = SelectorUtil.SELECT_TIMEOUT_NANOS / 100 * 80;
for (;;) {
wakenUp.set(false);
try {
SelectorUtil.select(selector);
long beforeSelect = System.nanoTime();
int selected = SelectorUtil.select(selector);
if (selected == 0) {
long timeBlocked = System.nanoTime() - beforeSelect;
if (timeBlocked < minSelectTimeout) {
// returned before the minSelectTimeout elapsed with nothing select.
// this may be the cause of the jdk epoll(..) bug, so increment the counter
// which we use later to see if its really the jdk bug.
selectReturnsImmediately++;
} else {
selectReturnsImmediately = 0;
}
if (selectReturnsImmediately == 10) {
// The selector returned immediately for 10 times in a row,
// so recreate one selector as it seems like we hit the
// famous epoll(..) jdk bug.
selector = recreateSelector();
selectReturnsImmediately = 0;
// try to select again
continue;
}
} else {
// reset counter
selectReturnsImmediately = 0;
}
// 'wakenUp.compareAndSet(false, true)' is always evaluated
// before calling 'selector.wakeup()' to reduce the wake-up
@ -415,6 +447,44 @@ class NioClientSocketPipelineSink extends AbstractNioChannelSink {
NioClientSocketChannel ch = (NioClientSocketChannel) k.attachment();
ch.worker.close(ch, succeededFuture(ch));
}
// Create a new selector and "transfer" all channels from the old
// selector to the new one
private Selector recreateSelector() throws IOException {
Selector newSelector = Selector.open();
Selector selector = this.selector;
this.selector = newSelector;
// loop over all the keys that are registered with the old Selector
// and register them with the new one
for (SelectionKey key: selector.keys()) {
SelectableChannel ch = key.channel();
int ops = key.interestOps();
Object att = key.attachment();
// cancel the old key
key.cancel();
try {
// register the channel with the new selector now
ch.register(newSelector, ops, att);
} catch (ClosedChannelException e) {
// close the Channel if we can't register it
AbstractNioChannel<?> channel = (AbstractNioChannel<?>) att;
channel.worker.close(channel, succeededFuture(channel));
}
key.cancel();
}
try {
// time to close the old selector as everything else is registered to the new one
selector.close();
} catch (Throwable t) {
logger.warn("Failed to close a selector.", t);
}
logger.debug("Recreated Selector because of possible jdk epoll(..) bug");
return newSelector;
}
}
private static final class RegisterTask implements Runnable {