private void dispose(Selector localSelector, LinkedBlockingQueue localSelectorTasks) {
Assert.eval(Thread.currentThread() == this);
if (localSelector != null) {
for (Object element : localSelector.keys()) {
try {
SelectionKey key = (SelectionKey) element;
cleanupChannel(key.channel(), null);
} catch (Exception e) {
logger.warn("Exception trying to close channel", e);
}
}
try {
localSelector.close();
} catch (Exception e) {
if ((Os.isMac()) && (Os.isUnix()) && (e.getMessage().equals("Bad file descriptor"))) {
// I can't find a specific bug about this, but I also can't seem to prevent the
// exception on the Mac.
// So just logging this as warning.
logger.warn("Exception trying to close selector: " + e.getMessage());
} else {
logger.error("Exception trying to close selector", e);
}
}
}
}
@Override
public void run() {
selectorManager.notifyReady();
while (selectorManager.isStarted() && selector.isOpen()) {
try {
beforeSelect();
wakenUp.set(false);
long before = -1;
// Wether to look jvm bug
if (isNeedLookingJVMBug()) {
before = System.currentTimeMillis();
}
long wait = DEFAULT_WAIT;
if (nextTimeout > 0) {
wait = nextTimeout;
}
int selected = selector.select(wait);
if (selected == 0) {
if (before != -1) {
lookJVMBug(before, selected, wait);
}
selectTries++;
// check tmeout and idle
nextTimeout = checkSessionTimeout();
continue;
} else {
selectTries = 0;
}
} catch (ClosedSelectorException e) {
break;
} catch (IOException e) {
log.error("Reactor select error", e);
if (selector.isOpen()) {
continue;
} else {
break;
}
}
Set<SelectionKey> selectedKeys = selector.selectedKeys();
gate.lock();
try {
postSelect(selectedKeys, selector.keys());
dispatchEvent(selectedKeys);
} finally {
gate.unlock();
}
}
if (selector != null) {
if (selector.isOpen()) {
try {
controller.closeChannel(selector);
selector.close();
} catch (IOException e) {
controller.notifyException(e);
log.error("stop reactor error", e);
}
}
}
}
/** Return the set of SelectionKey registered on this Selector. */
public Set<SelectionKey> keys() {
if (selector != null) {
return selector.keys();
} else {
throw new IllegalStateException("Selector is not created!");
}
}
void unregisterChannels(SelectionKeyRegistrationReference registrationReference)
throws Exception {
registrationReference.cancelRegistration();
SelectorIntraband defaultIntraband = (SelectorIntraband) registrationReference.getIntraband();
Selector selector = defaultIntraband.selector;
Set<SelectionKey> keys = selector.keys();
while (!keys.isEmpty()) {
selector.wakeup();
}
SelectionKey readSelectionKey = registrationReference.readSelectionKey;
SelectionKey writeSelectionKey = registrationReference.writeSelectionKey;
SelectableChannel readSelectableChannel = readSelectionKey.channel();
SelectableChannel writeSelectableChannel = writeSelectionKey.channel();
while (readSelectableChannel.keyFor(selector) != null) ;
while (writeSelectableChannel.keyFor(selector) != null) ;
writeSelectableChannel.close();
readSelectableChannel.close();
}
public boolean processNow() throws IOException {
int numKeys = selector.selectNow();
if (selector.keys().isEmpty()) return false;
if (numKeys > 0) dispatchMessages();
return true;
}
public void stop() {
try {
lock.lock();
if (networkJob != null && !networkJob.isCancelled()) {
networkJob.cancel(true);
networkJob = null;
}
try {
if (selector != null) {
selector.wakeup();
boolean isContinue = true;
while (isContinue) {
try {
for (SelectionKey selectionKey : selector.keys()) {
selectionKey.channel().close();
selectionKey.cancel();
}
isContinue = false; // continue till all keys are cancelled
} catch (ConcurrentModificationException e) {
logger.warn(
"An exception occurred while closing a selector key : '{}'", e.getMessage());
}
}
selector.close();
}
} catch (IOException e) {
logger.warn("An exception occurred while closing the selector : '{}'", e.getMessage());
}
if (broadcastKey != null) {
try {
broadcastKey.channel().close();
} catch (IOException e) {
logger.warn(
"An exception occurred while closing the broadcast channel : '{}'", e.getMessage());
}
}
if (unicastKey != null) {
try {
unicastKey.channel().close();
} catch (IOException e) {
logger.warn(
"An exception occurred while closing the unicast channel : '{}'", e.getMessage());
}
}
ipAddress = null;
} finally {
lock.unlock();
}
}
public void shutdown(final long period, final TimeUnit timeUnit) {
channelDispatcher.stop();
for (SelectionKey selectionKey : socketChannelSelector.keys()) {
final AbstractChannelReader reader = (AbstractChannelReader) selectionKey.attachment();
selectionKey.cancel();
if (reader != null) {
while (!reader.isClosed()) {
try {
Thread.sleep(channelReaderFrequencyMSecs);
} catch (InterruptedException e) {
}
}
final ScheduledFuture<?> readerFuture = reader.getScheduledFuture();
readerFuture.cancel(false);
}
IOUtils.closeQuietly(
selectionKey
.channel()); // should already be closed via reader, but if reader did not exist...
}
IOUtils.closeQuietly(socketChannelSelector);
for (SelectionKey selectionKey : serverSocketSelector.keys()) {
selectionKey.cancel();
IOUtils.closeQuietly(selectionKey.channel());
}
IOUtils.closeQuietly(serverSocketSelector);
executor.shutdown();
try {
executor.awaitTermination(period, timeUnit);
} catch (final InterruptedException ex) {
LOGGER.warn("Interrupted while trying to shutdown executor");
}
final int currentBufferPoolSize = bufferPool.size();
final String warning =
(currentBufferPoolSize != initialBufferPoolSize)
? "Initial buffer count="
+ initialBufferPoolSize
+ " Current buffer count="
+ currentBufferPoolSize
+ " Could indicate a buffer leak. Ensure all consumers are executed until they complete."
: "";
LOGGER.info("Channel listener shutdown. " + warning);
}
private void listen() throws IOException {
// TODO Auto-generated method stub
// 监听所有的事件
while (true) {
selector.select(); // 返回值为本次触发的事件数
Set<SelectionKey> selectionKeys = selector.keys();
for (SelectionKey key : selectionKeys) {
handle(key);
}
selectionKeys.clear(); // 清除处理过的事件
}
}
/** MemcachedClient calls this method to handle IO over the connections. */
@SuppressWarnings("unchecked")
public void handleIO() throws IOException {
if (shutDown) {
throw new IOException("No IO while shut down");
}
// Deal with all of the stuff that's been added, but may not be marked
// writable.
handleInputQueue();
getLogger().debug("Done dealing with queue.");
long delay = 0;
if (!reconnectQueue.isEmpty()) {
long now = System.currentTimeMillis();
long then = reconnectQueue.firstKey();
delay = Math.max(then - now, 1);
}
getLogger().debug("Selecting with delay of %sms", delay);
assert selectorsMakeSense() : "Selectors don't make sense.";
int selected = selector.select(delay);
Set<SelectionKey> selectedKeys = selector.selectedKeys();
if (selectedKeys.isEmpty() && !shutDown) {
getLogger().debug("No selectors ready, interrupted: " + Thread.interrupted());
if (++emptySelects > DOUBLE_CHECK_EMPTY) {
for (SelectionKey sk : selector.keys()) {
getLogger().info("%s has %s, interested in %s", sk, sk.readyOps(), sk.interestOps());
if (sk.readyOps() != 0) {
getLogger().info("%s has a ready op, handling IO", sk);
handleIO(sk);
} else {
queueReconnect((MemcachedNode) sk.attachment());
}
}
assert emptySelects < EXCESSIVE_EMPTY : "Too many empty selects";
}
} else {
getLogger().debug("Selected %d, selected %d keys", selected, selectedKeys.size());
emptySelects = 0;
for (SelectionKey sk : selectedKeys) {
handleIO(sk);
} // for each selector
selectedKeys.clear();
}
if (!shutDown && !reconnectQueue.isEmpty()) {
attemptReconnects();
}
}
public void close() {
selectable = false;
selector.wakeup();
// forcibly close remaining sockets
for (SelectionKey key : selector.keys()) {
if (key != null) {
safelyClose(key.channel());
}
}
safelyClose(selector);
safelyClose(agent);
safelyClose(channel);
if (authSocket != null) {
FileUtils.deleteQuietly(new File(authSocket));
}
}
@Override
public void update(Observable o, Object arg) {
// ENVIAR POSICIONS
// Si el que volem és actualitzar les posicions al joc
if (arg instanceof int[]) {
int[] lastPosition = (int[]) arg;
enviar(lastPosition);
}
// ACABAR PARTIDA
// Si el que volem és acabar la partida
else if (arg instanceof Integer) {
if ((int) arg == Const.ACABA_PARTIDA) {
System.out.println(
"~Partida Acabada | Desconectem " + arraySocketChannels.size() + " jugadors");
controlador.acaba();
enviar(Const.FINISH_CODE);
System.out.print("Cancelació de les Claus...");
// CONCURRENCIA claus
// Les claus son recursos compartits. Un dels problemes que ens podem trobar,
// es que abans de que els clients rebin el FINISH_CODE, enviïn un paquet,
// i quan es procesi la clau sigui cancelada.
// CANCELEM LES CLAUS
// Hem de cancelar només les claus que pertanyen a conexions amb
// clients, que son les que retornen un SocketChannel quan invoquem
// key.channel()
synchronized (this) {
for (SelectionKey key : selector.keys()) {
if (key.channel() instanceof SocketChannel
&& arraySocketChannels.contains((SocketChannel) key.channel())) {
key.cancel();
System.out.print(" | Clau cancelada");
}
}
}
arraySocketChannels.clear();
System.out.println("\nArray de SocketChannels 'cleared'");
}
}
}
/**
* Cleans up the contents of the selector, closing any server socket channels that might be
* associated with it. Any connections that might have been established through those channels
* should not be impacted.
*/
private void cleanUpSelector() {
try {
for (SelectionKey key : selector.keys()) {
try {
key.cancel();
} catch (Exception e) {
logger.traceException(e);
}
try {
key.channel().close();
} catch (Exception e) {
logger.traceException(e);
}
}
} catch (Exception e) {
logger.traceException(e);
}
}
public boolean process(long timeout) throws IOException {
while (timeout > 0) {
long start = System.nanoTime();
int numKeys = selector.select(timeout);
long end = System.nanoTime();
if (selector.keys().isEmpty()) return false;
if (numKeys > 0) {
dispatchMessages();
break;
}
timeout -= TimeUnit.NANOSECONDS.toMillis(end - start);
if (timeout <= 0) {
break;
}
}
return true;
}
/**
* Check session timeout or idle
*
* @return
*/
private final long checkSessionTimeout() {
long nextTimeout = 0;
if (configuration.getCheckSessionTimeoutInterval() > 0) {
gate.lock();
try {
if (selectTries * 1000 >= configuration.getCheckSessionTimeoutInterval()) {
nextTimeout = configuration.getCheckSessionTimeoutInterval();
for (SelectionKey key : selector.keys()) {
if (key.attachment() != null) {
long n = checkExpiredIdle(key, getSessionFromAttchment(key));
nextTimeout = n < nextTimeout ? n : nextTimeout;
}
}
selectTries = 0;
}
} finally {
gate.unlock();
}
}
return nextTimeout;
}
protected void timeout(int keyCount, boolean hasEvents) {
long now = System.currentTimeMillis();
// This method is called on every loop of the Poller. Don't process
// timeouts on every loop of the Poller since that would create too
// much load and timeouts can afford to wait a few seconds.
// However, do process timeouts if any of the following are true:
// - the selector simply timed out (suggests there isn't much load)
// - the nextExpiration time has passed
// - the server socket is being closed
if (nextExpiration > 0 && (keyCount > 0 || hasEvents) && (now < nextExpiration) && !close) {
return;
}
// timeout
int keycount = 0;
try {
for (SelectionKey key : selector.keys()) {
keycount++;
try {
NioSocketWrapper ka = (NioSocketWrapper) key.attachment();
if (ka == null) {
cancelledKey(key); // we don't support any keys without attachments
} else if (close) {
key.interestOps(0);
ka.interestOps(0); // avoid duplicate stop calls
processKey(key, ka);
} else if ((ka.interestOps() & SelectionKey.OP_READ) == SelectionKey.OP_READ
|| (ka.interestOps() & SelectionKey.OP_WRITE) == SelectionKey.OP_WRITE) {
boolean isTimedOut = false;
// Check for read timeout
if ((ka.interestOps() & SelectionKey.OP_READ) == SelectionKey.OP_READ) {
long delta = now - ka.getLastRead();
long timeout = ka.getReadTimeout();
isTimedOut = timeout > 0 && delta > timeout;
}
// Check for write timeout
if (!isTimedOut
&& (ka.interestOps() & SelectionKey.OP_WRITE) == SelectionKey.OP_WRITE) {
long delta = now - ka.getLastWrite();
long timeout = ka.getWriteTimeout();
isTimedOut = timeout > 0 && delta > timeout;
}
if (isTimedOut) {
key.interestOps(0);
ka.interestOps(0); // avoid duplicate timeout calls
ka.setError(new SocketTimeoutException());
if (!processSocket(ka, SocketEvent.ERROR, true)) {
cancelledKey(key);
}
}
}
} catch (CancelledKeyException ckx) {
cancelledKey(key);
}
} // for
} catch (ConcurrentModificationException cme) {
// See https://bz.apache.org/bugzilla/show_bug.cgi?id=57943
log.warn(sm.getString("endpoint.nio.timeoutCme"), cme);
}
long prevExp = nextExpiration; // for logging purposes only
nextExpiration = System.currentTimeMillis() + socketProperties.getTimeoutInterval();
if (log.isTraceEnabled()) {
log.trace(
"timeout completed: keys processed="
+ keycount
+ "; now="
+ now
+ "; nextExpiration="
+ prevExp
+ "; keyCount="
+ keyCount
+ "; hasEvents="
+ hasEvents
+ "; eval="
+ ((now < prevExp) && (keyCount > 0 || hasEvents) && (!close)));
}
}
@SelectorThreadOnly
private void abortAll(Throwable e) {
Set<NioTransport> pairs = new HashSet<NioTransport>();
for (SelectionKey k : selector.keys()) pairs.add((NioTransport) k.attachment());
for (NioTransport p : pairs) p.abort(e);
}
/**
* Attend to channels in the hub.
*
* <p>This method returns when {@link #close()} is called and the selector is shut down.
*/
public void run() {
synchronized (startedLock) {
started = true;
selectorThread = Thread.currentThread();
startedLock.notifyAll();
}
final String oldName = selectorThread.getName();
try {
while (true) {
try {
while (true) {
Callable<Void, IOException> t = selectorTasks.poll();
if (t == null) break;
try {
t.call();
} catch (IOException e) {
LOGGER.log(WARNING, "Failed to process selectorTasks", e);
// but keep on at the next task
}
}
selectorThread.setName(
"NioChannelHub keys=" + selector.keys().size() + " gen=" + (gen++) + ": " + oldName);
selector.select();
} catch (IOException e) {
whatKilledSelectorThread = e;
LOGGER.log(WARNING, "Failed to select", e);
abortAll(e);
return;
}
Iterator<SelectionKey> itr = selector.selectedKeys().iterator();
while (itr.hasNext()) {
SelectionKey key = itr.next();
itr.remove();
Object a = key.attachment();
if (a instanceof NioTransport) {
final NioTransport t = (NioTransport) a;
try {
if (key.isReadable()) {
if (t.rb.receive(t.rr()) == -1) {
t.closeR();
}
final byte[] buf = new byte[2]; // space for reading the chunk header
int pos = 0;
int packetSize = 0;
while (true) {
if (t.rb.peek(pos, buf) < buf.length)
break; // we don't have enough to parse header
int header = ChunkHeader.parse(buf);
int chunk = ChunkHeader.length(header);
pos += buf.length + chunk;
packetSize += chunk;
boolean last = ChunkHeader.isLast(header);
if (last
&& pos <= t.rb.readable()) { // do we have the whole packet in our buffer?
// read in the whole packet
final byte[] packet = new byte[packetSize];
int r_ptr = 0;
do {
int r = t.rb.readNonBlocking(buf);
assert r == buf.length;
header = ChunkHeader.parse(buf);
chunk = ChunkHeader.length(header);
last = ChunkHeader.isLast(header);
t.rb.readNonBlocking(packet, r_ptr, chunk);
packetSize -= chunk;
r_ptr += chunk;
} while (!last);
assert packetSize == 0;
if (packet.length > 0) {
t.swimLane.submit(
new Runnable() {
public void run() {
t.receiver.handle(packet);
}
});
}
pos = 0;
}
}
if (t.rb.writable() == 0 && t.rb.readable() > 0) {
String msg =
"Command buffer overflow. Read "
+ t.rb.readable()
+ " bytes but still too small for a single command";
LOGGER.log(WARNING, msg);
// to avoid infinite hang, abort this connection
t.abort(new IOException(msg));
}
if (t.rb.isClosed()) {
// EOF. process this synchronously with respect to packets
t.swimLane.submit(
new Runnable() {
public void run() {
// if this EOF is unexpected, report an error.
if (!t.getChannel().isInClosed())
t.getChannel().terminate(new EOFException());
}
});
}
}
if (key.isValid() && key.isWritable()) {
t.wb.send(t.ww());
if (t.wb.readable() < 0) {
// done with sending all the data
t.closeW();
}
}
t.reregister();
} catch (IOException e) {
LOGGER.log(WARNING, "Communication problem", e);
t.abort(e);
} catch (CancelledKeyException e) {
// see JENKINS-24050. I don't understand how this can happen, given that the selector
// thread is the only thread that cancels keys. So to better understand what's going
// on,
// report the problem.
LOGGER.log(SEVERE, "Unexpected key cancellation for " + t, e);
// to be on the safe side, abort the communication. if we don't do this, it's possible
// that the key never gets re-registered to the selector, and the traffic will hang
// on this channel.
t.abort(e);
}
} else {
onSelected(key);
}
}
}
} catch (ClosedSelectorException e) {
// end normally
// TODO: what happens to all the registered ChannelPairs? don't we need to shut them down?
whatKilledSelectorThread = e;
} catch (RuntimeException e) {
whatKilledSelectorThread = e;
LOGGER.log(WARNING, "Unexpected shutdown of the selector thread", e);
abortAll(e);
throw e;
} catch (Error e) {
whatKilledSelectorThread = e;
LOGGER.log(WARNING, "Unexpected shutdown of the selector thread", e);
abortAll(e);
throw e;
} finally {
selectorThread.setName(oldName);
selectorThread = null;
if (whatKilledSelectorThread == null)
whatKilledSelectorThread = new AssertionError("NioChannelHub shouldn't exit normally");
}
}
@Override
public void run() {
boolean shutdown = false;
Selector selector = this.selector;
long lastConnectTimeoutCheckTimeNanos = System.nanoTime();
for (; ; ) {
wakenUp.set(false);
try {
int selectedKeyCount = selector.select(10);
// 'wakenUp.compareAndSet(false, true)' is always evaluated
// before calling 'selector.wakeup()' to reduce the wake-up
// overhead. (Selector.wakeup() is an expensive operation.)
//
// However, there is a race condition in this approach.
// The race condition is triggered when 'wakenUp' is set to
// true too early.
//
// 'wakenUp' is set to true too early if:
// 1) Selector is waken up between 'wakenUp.set(false)' and
// 'selector.select(...)'. (BAD)
// 2) Selector is waken up between 'selector.select(...)' and
// 'if (wakenUp.get()) { ... }'. (OK)
//
// In the first case, 'wakenUp' is set to true and the
// following 'selector.select(...)' will wake up immediately.
// Until 'wakenUp' is set to false again in the next round,
// 'wakenUp.compareAndSet(false, true)' will fail, and therefore
// any attempt to wake up the Selector will fail, too, causing
// the following 'selector.select(...)' call to block
// unnecessarily.
//
// To fix this problem, we wake up the selector again if wakenUp
// is true immediately after selector.select(...).
// It is inefficient in that it wakes up the selector for both
// the first case (BAD - wake-up required) and the second case
// (OK - no wake-up required).
if (wakenUp.get()) {
selector.wakeup();
}
processRegisterTaskQueue();
if (selectedKeyCount > 0) {
processSelectedKeys(selector.selectedKeys());
}
// Handle connection timeout every 10 milliseconds approximately.
long currentTimeNanos = System.nanoTime();
if (currentTimeNanos - lastConnectTimeoutCheckTimeNanos >= 10 * 1000000L) {
lastConnectTimeoutCheckTimeNanos = currentTimeNanos;
processConnectTimeout(selector.keys(), currentTimeNanos);
}
// Exit the loop when there's nothing to handle.
// The shutdown flag is used to delay the shutdown of this
// loop to avoid excessive Selector creation when
// connection attempts are made in a one-by-one manner
// instead of concurrent manner.
if (selector.keys().isEmpty()) {
if (shutdown
|| bossExecutor instanceof ExecutorService
&& ((ExecutorService) bossExecutor).isShutdown()) {
synchronized (startStopLock) {
if (registerTaskQueue.isEmpty() && selector.keys().isEmpty()) {
started = false;
try {
selector.close();
} catch (IOException e) {
if (logger.isWarnEnabled()) {
logger.warn("Failed to close a selector.", e);
}
} finally {
this.selector = null;
}
break;
} else {
shutdown = false;
}
}
} else {
// Give one more second.
shutdown = true;
}
} else {
shutdown = false;
}
} catch (Throwable t) {
if (logger.isWarnEnabled()) {
logger.warn("Unexpected exception in the selector loop.", t);
}
// Prevent possible consecutive immediate failures.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore.
}
}
}
}
static void releaseTemporarySelector(Selector sel) throws IOException {
// Selector should be empty
sel.selectNow(); // Flush cancelled keys
assert sel.keys().isEmpty() : "Temporary selector not empty";
localSelectorWrapper.set(null);
}
@Override
public void run() {
LOG.debug(getName() + ": starting");
SERVER.set(Server.this);
long lastPurgeTime = 0; // last check for old calls.
while (running) {
try {
waitPending(); // If a channel is being registered, wait.
writeSelector.select(PURGE_INTERVAL);
Iterator<SelectionKey> iter = writeSelector.selectedKeys().iterator();
while (iter.hasNext()) {
SelectionKey key = iter.next();
iter.remove();
try {
if (key.isValid() && key.isWritable()) {
doAsyncWrite(key);
}
} catch (IOException e) {
LOG.info(getName() + ": doAsyncWrite threw exception " + e);
}
}
long now = System.currentTimeMillis();
if (now < lastPurgeTime + PURGE_INTERVAL) {
continue;
}
lastPurgeTime = now;
//
// If there were some calls that have not been sent out for a
// long time, discard them.
//
ArrayList<Call> calls;
// get the list of channels from list of keys.
synchronized (writeSelector.keys()) {
calls = new ArrayList<Call>(writeSelector.keys().size());
iter = writeSelector.keys().iterator();
while (iter.hasNext()) {
SelectionKey key = iter.next();
Call call = (Call) key.attachment();
if (call != null && key.channel() == call.connection.channel) {
calls.add(call);
}
}
}
for (Call call : calls) {
try {
doPurge(call, now);
} catch (IOException e) {
LOG.warn("Error in purging old calls " + e);
}
}
} catch (OutOfMemoryError e) {
//
// we can run out of memory if we have too many threads
// log the event and sleep for a minute and give
// some thread(s) a chance to finish
//
LOG.warn("Out of Memory in server select", e);
try {
Thread.sleep(60000);
} catch (Exception ie) {
}
} catch (Exception e) {
LOG.warn("Exception in Responder " + e.toString());
}
}
LOG.debug("Stopping " + this.getName());
this.shutDown = true;
}
public void run() {
while (!stopping) {
// Execute any due timers.
long timeout = execute_timers();
if (retired) {
for (SelectableChannel ch : fd_table.keySet()) {
SelectionKey key = ch.keyFor(selector);
if (key == null) {
try {
key = ch.register(selector, pollset.get(ch));
key.attach(fd_table.get(ch));
} catch (ClosedChannelException e) {
continue;
}
} else if (key.isValid()) {
key.attach(fd_table.get(ch));
key.interestOps(pollset.get(ch));
}
}
for (SelectionKey key : selector.keys()) {
if (!fd_table.containsKey(key.channel())) {
// removed
key.cancel();
}
}
retired = false;
}
// Wait for events.
int rc;
try {
rc = selector.select(timeout);
} catch (IOException e) {
throw new ZError.IOException(e);
}
if (rc == 0) continue;
Iterator<SelectionKey> it = selector.selectedKeys().iterator();
while (it.hasNext()) {
SelectionKey key = it.next();
IPollEvents evt = (IPollEvents) key.attachment();
it.remove();
try {
if (key.isWritable()) {
evt.out_event();
}
if (key.isReadable()) {
evt.in_event();
} else if (key.isAcceptable()) {
evt.accept_event();
} else if (key.isConnectable()) {
evt.connect_event();
}
} catch (CancelledKeyException e) {
// channel might have been closed
}
}
}
stopped = true;
}
@Override
public void run() {
thread = Thread.currentThread();
boolean shutdown = false;
Selector selector = this.selector;
for (; ; ) {
wakenUp.set(false);
if (CONSTRAINT_LEVEL != 0) {
selectorGuard.writeLock().lock();
// This empty synchronization block prevents the selector
// from acquiring its lock.
selectorGuard.writeLock().unlock();
}
try {
SelectorUtil.select(selector);
// 'wakenUp.compareAndSet(false, true)' is always evaluated
// before calling 'selector.wakeup()' to reduce the wake-up
// overhead. (Selector.wakeup() is an expensive operation.)
//
// However, there is a race condition in this approach.
// The race condition is triggered when 'wakenUp' is set to
// true too early.
//
// 'wakenUp' is set to true too early if:
// 1) Selector is waken up between 'wakenUp.set(false)' and
// 'selector.select(...)'. (BAD)
// 2) Selector is waken up between 'selector.select(...)' and
// 'if (wakenUp.get()) { ... }'. (OK)
//
// In the first case, 'wakenUp' is set to true and the
// following 'selector.select(...)' will wake up immediately.
// Until 'wakenUp' is set to false again in the next round,
// 'wakenUp.compareAndSet(false, true)' will fail, and therefore
// any attempt to wake up the Selector will fail, too, causing
// the following 'selector.select(...)' call to block
// unnecessarily.
//
// To fix this problem, we wake up the selector again if wakenUp
// is true immediately after selector.select(...).
// It is inefficient in that it wakes up the selector for both
// the first case (BAD - wake-up required) and the second case
// (OK - no wake-up required).
if (wakenUp.get()) {
selector.wakeup();
}
cancelledKeys = 0;
processRegisterTaskQueue();
processEventQueue();
processWriteTaskQueue();
processSelectedKeys(selector.selectedKeys());
// Exit the loop when there's nothing to handle.
// The shutdown flag is used to delay the shutdown of this
// loop to avoid excessive Selector creation when
// connections are registered in a one-by-one manner instead of
// concurrent manner.
if (selector.keys().isEmpty()) {
if (shutdown
|| executor instanceof ExecutorService && ((ExecutorService) executor).isShutdown()) {
synchronized (startStopLock) {
if (registerTaskQueue.isEmpty() && selector.keys().isEmpty()) {
started = false;
try {
selector.close();
} catch (IOException e) {
if (logger.isWarnEnabled()) {
logger.warn("Failed to close a selector.", e);
}
} finally {
this.selector = null;
}
break;
} else {
shutdown = false;
}
}
} else {
// Give one more second.
shutdown = true;
}
} else {
shutdown = false;
}
} catch (Throwable t) {
if (logger.isWarnEnabled()) {
logger.warn("Unexpected exception in the selector loop.", t);
}
// Prevent possible consecutive immediate failures that lead to
// excessive CPU consumption.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore.
}
}
}
}
/** Shuntdown this instance by closing its Selector and associated channels. */
public void shutdown() {
// If shutdown was called for this SelectorHandler
if (isShutDown.getAndSet(true)) return;
stateHolder.setState(State.STOPPED);
if (selector != null) {
try {
boolean isContinue = true;
while (isContinue) {
try {
for (SelectionKey selectionKey : selector.keys()) {
selectionKeyHandler.close(selectionKey);
}
isContinue = false;
} catch (ConcurrentModificationException e) {
// ignore
}
}
} catch (ClosedSelectorException e) {
// If Selector is already closed - OK
}
}
try {
if (serverSocket != null) {
serverSocket.close();
serverSocket = null;
}
} catch (Throwable ex) {
Controller.logger().log(Level.SEVERE, "serverSocket.close", ex);
}
try {
if (serverSocketChannel != null) {
serverSocketChannel.close();
serverSocketChannel = null;
}
} catch (Throwable ex) {
Controller.logger().log(Level.SEVERE, "serverSocketChannel.close", ex);
}
try {
if (selector != null) selector.close();
} catch (Throwable ex) {
Controller.logger().log(Level.SEVERE, "selector.close", ex);
}
if (asyncQueueReader != null) {
asyncQueueReader.close();
asyncQueueReader = null;
}
if (asyncQueueWriter != null) {
asyncQueueWriter.close();
asyncQueueWriter = null;
}
selectorHandlerTasks.clear();
attributes = null;
}
/**
* Look jvm bug
*
* @param before
* @param selected
* @param wait
* @return
* @throws IOException
*/
private boolean lookJVMBug(long before, int selected, long wait) throws IOException {
boolean seeing = false;
long now = System.currentTimeMillis();
if (JVMBUG_THRESHHOLD > 0
&& selected == 0
&& wait > JVMBUG_THRESHHOLD
&& now - before < wait / 4
&& !wakenUp.get() /* waken up */
&& !Thread.currentThread().isInterrupted() /* Interrupted */) {
jvmBug.incrementAndGet();
if (jvmBug.get() >= JVMBUG_THRESHHOLD2) {
gate.lock();
try {
lastJVMBug = now;
log.warn(
"JVM bug occured at "
+ new Date(lastJVMBug)
+ ",http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6403933,reactIndex="
+ reactorIndex);
if (jvmBug1) {
log.debug("seeing JVM BUG(s) - recreating selector,reactIndex=" + reactorIndex);
} else {
jvmBug1 = true;
log.info("seeing JVM BUG(s) - recreating selector,reactIndex=" + reactorIndex);
}
seeing = true;
final Selector new_selector = SystemUtils.openSelector();
for (SelectionKey k : selector.keys()) {
if (!k.isValid() || k.interestOps() == 0) {
continue;
}
final SelectableChannel channel = k.channel();
final Object attachment = k.attachment();
channel.register(new_selector, k.interestOps(), attachment);
}
selector.close();
selector = new_selector;
} finally {
gate.unlock();
}
jvmBug.set(0);
} else if (jvmBug.get() == JVMBUG_THRESHHOLD || jvmBug.get() == JVMBUG_THRESHHOLD1) {
if (jvmBug0) {
log.debug("seeing JVM BUG(s) - cancelling interestOps==0,reactIndex=" + reactorIndex);
} else {
jvmBug0 = true;
log.info("seeing JVM BUG(s) - cancelling interestOps==0,reactIndex=" + reactorIndex);
}
gate.lock();
seeing = true;
try {
for (SelectionKey k : selector.keys()) {
if (k.isValid() && k.interestOps() == 0) {
k.cancel();
}
}
} finally {
gate.unlock();
}
}
} else {
jvmBug.set(0);
}
return seeing;
}