org.glassfish.grizzly.nio.tmpselectors.TemporarySelectorPool Maven / Gradle / Ivy
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package org.glassfish.grizzly.nio.tmpselectors;
import org.glassfish.grizzly.Grizzly;
import java.io.IOException;
import java.nio.channels.Selector;
import java.nio.channels.spi.SelectorProvider;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.glassfish.grizzly.localization.LogMessages;
import org.glassfish.grizzly.nio.Selectors;
/**
*
* @author oleksiys
*/
public class TemporarySelectorPool {
private static final Logger LOGGER = Grizzly.logger(TemporarySelectorPool.class);
public static final int DEFAULT_SELECTORS_COUNT = 32;
private static final int MISS_THRESHOLD = 10000;
/**
* The max number of Selector to create.
*/
private volatile int maxPoolSize;
private final AtomicBoolean isClosed;
/**
* Cache of Selector
*/
private final Queue selectors;
/**
* The current number of Selectors in the pool.
*/
private final AtomicInteger poolSize;
/**
* Number of times poll execution didn't find the available selector in the pool.
*/
private final AtomicInteger missesCounter;
private final SelectorProvider selectorProvider;
public TemporarySelectorPool(final SelectorProvider selectorProvider) {
this(selectorProvider, DEFAULT_SELECTORS_COUNT);
}
public TemporarySelectorPool(final SelectorProvider selectorProvider,
final int selectorsCount) {
this.selectorProvider = selectorProvider;
this.maxPoolSize = selectorsCount;
isClosed = new AtomicBoolean();
selectors = new ConcurrentLinkedQueue();
poolSize = new AtomicInteger();
missesCounter = new AtomicInteger();
}
public synchronized int size() {
return maxPoolSize;
}
public synchronized void setSize(int size) throws IOException {
if (isClosed.get()) {
return;
}
missesCounter.set(0);
this.maxPoolSize = size;
}
public SelectorProvider getSelectorProvider() {
return selectorProvider;
}
public Selector poll() throws IOException {
Selector selector = selectors.poll();
if (selector != null) {
poolSize.decrementAndGet();
} else {
try {
selector = Selectors.newSelector(selectorProvider);
} catch (IOException e) {
LOGGER.log(Level.WARNING,
LogMessages.WARNING_GRIZZLY_TEMPORARY_SELECTOR_POOL_CREATE_SELECTOR_EXCEPTION(),
e);
}
final int missesCount = missesCounter.incrementAndGet();
if (missesCount % MISS_THRESHOLD == 0) {
LOGGER.log(Level.WARNING,
LogMessages.WARNING_GRIZZLY_TEMPORARY_SELECTOR_POOL_MISSES_EXCEPTION(missesCount, maxPoolSize));
}
}
return selector;
}
public void offer(Selector selector) {
if (selector == null) {
return;
}
final boolean wasReturned;
if (poolSize.getAndIncrement() < maxPoolSize
&& (selector = checkSelector(selector)) != null) {
selectors.offer(selector);
wasReturned = true;
} else {
poolSize.decrementAndGet();
if (selector == null) {
return;
}
wasReturned = false;
}
if (isClosed.get()) {
if (selectors.remove(selector)) {
closeSelector(selector);
}
} else if (!wasReturned) {
closeSelector(selector);
}
}
public synchronized void close() {
if (!isClosed.getAndSet(true)) {
Selector selector;
while ((selector = selectors.poll()) != null) {
closeSelector(selector);
}
}
}
private void closeSelector(Selector selector) {
try {
selector.close();
} catch (IOException e) {
if (LOGGER.isLoggable(Level.FINE)) {
LOGGER.log(Level.FINE, "TemporarySelectorFactory: error " +
"occurred when trying to close the Selector", e);
}
}
}
private Selector checkSelector(final Selector selector) {
try {
selector.selectNow();
return selector;
} catch (IOException e) {
LOGGER.log(Level.WARNING,
LogMessages.WARNING_GRIZZLY_TEMPORARY_SELECTOR_POOL_SELECTOR_FAILURE_EXCEPTION(),
e);
try {
return Selectors.newSelector(selectorProvider);
} catch (IOException ee) {
LOGGER.log(Level.WARNING,
LogMessages.WARNING_GRIZZLY_TEMPORARY_SELECTOR_POOL_CREATE_SELECTOR_EXCEPTION(),
ee);
}
}
return null;
}
}