org.jboss.netty.channel.socket.nio.NioProviderMetadata Maven / Gradle / Ivy
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The Netty project is an effort to provide an asynchronous event-driven
network application framework and tools for rapid development of
maintainable high performance and high scalability protocol servers and
clients. In other words, Netty is a NIO client server framework which
enables quick and easy development of network applications such as protocol
servers and clients. It greatly simplifies and streamlines network
programming such as TCP and UDP socket server.
/*
* Copyright 2009 Red Hat, Inc.
*
* Red Hat licenses this file to you under the Apache License, version 2.0
* (the "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package org.jboss.netty.channel.socket.nio;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.spi.SelectorProvider;
import java.util.Set;
import java.util.Map.Entry;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
import org.jboss.netty.util.internal.SystemPropertyUtil;
/**
* Provides information which is specific to a NIO service provider
* implementation.
*
* @author The Netty Project
* @author Trustin Lee
*
* @version $Rev: 2162 $, $Date: 2010-02-18 11:23:51 +0900 (Thu, 18 Feb 2010) $
*
*/
class NioProviderMetadata {
static final InternalLogger logger =
InternalLoggerFactory.getInstance(NioProviderMetadata.class);
private static final String CONSTRAINT_LEVEL_PROPERTY =
"org.jboss.netty.channel.socket.nio.constraintLevel";
private static final String OLD_CONSTRAINT_LEVEL_PROPERTY =
"java.nio.channels.spi.constraintLevel";
/**
* 0 - no need to wake up to get / set interestOps (most cases)
* 1 - no need to wake up to get interestOps, but need to wake up to set.
* 2 - need to wake up to get / set interestOps (old providers)
*/
static final int CONSTRAINT_LEVEL;
static {
int constraintLevel = -1;
// Use the system property if possible.
constraintLevel = SystemPropertyUtil.get(CONSTRAINT_LEVEL_PROPERTY, -1);
if (constraintLevel < 0 || constraintLevel > 2) {
// Try the old property.
constraintLevel = SystemPropertyUtil.get(OLD_CONSTRAINT_LEVEL_PROPERTY, -1);
if (constraintLevel < 0 || constraintLevel > 2) {
constraintLevel = -1;
} else {
logger.warn(
"System property '" +
OLD_CONSTRAINT_LEVEL_PROPERTY +
"' has been deprecated. Use '" +
CONSTRAINT_LEVEL_PROPERTY + "' instead.");
}
}
if (constraintLevel >= 0) {
logger.debug(
"Setting the NIO constraint level to: " + constraintLevel);
}
if (constraintLevel < 0) {
constraintLevel = detectConstraintLevelFromSystemProperties();
if (constraintLevel < 0) {
constraintLevel = 2;
logger.debug(
"Couldn't determine the NIO constraint level from " +
"the system properties; using the safest level (2)");
} else if (constraintLevel != 0) {
logger.info(
"Using the autodetected NIO constraint level: " +
constraintLevel +
" (Use better NIO provider for better performance)");
} else {
logger.debug(
"Using the autodetected NIO constraint level: " +
constraintLevel);
}
}
CONSTRAINT_LEVEL = constraintLevel;
if (CONSTRAINT_LEVEL < 0 || CONSTRAINT_LEVEL > 2) {
throw new Error(
"Unexpected NIO constraint level: " +
CONSTRAINT_LEVEL + ", please report this error.");
}
}
private static int detectConstraintLevelFromSystemProperties() {
String version = SystemPropertyUtil.get("java.specification.version");
String vminfo = SystemPropertyUtil.get("java.vm.info", "");
String os = SystemPropertyUtil.get("os.name");
String vendor = SystemPropertyUtil.get("java.vm.vendor");
String provider;
try {
provider = SelectorProvider.provider().getClass().getName();
} catch (Exception e) {
// Perhaps security exception.
provider = null;
}
if (version == null || os == null || vendor == null || provider == null) {
return -1;
}
os = os.toLowerCase();
vendor = vendor.toLowerCase();
// System.out.println(version);
// System.out.println(vminfo);
// System.out.println(os);
// System.out.println(vendor);
// System.out.println(provider);
// Sun JVM
if (vendor.indexOf("sun") >= 0) {
// Linux
if (os.indexOf("linux") >= 0) {
if (provider.equals("sun.nio.ch.EPollSelectorProvider") ||
provider.equals("sun.nio.ch.PollSelectorProvider")) {
return 0;
}
// Windows
} else if (os.indexOf("windows") >= 0) {
if (provider.equals("sun.nio.ch.WindowsSelectorProvider")) {
return 0;
}
// Solaris
} else if (os.indexOf("sun") >= 0 || os.indexOf("solaris") >= 0) {
if (provider.equals("sun.nio.ch.DevPollSelectorProvider")) {
return 0;
}
}
// Apple JVM
} else if (vendor.indexOf("apple") >= 0) {
// Mac OS
if (os.indexOf("mac") >= 0 && os.indexOf("os") >= 0) {
if (provider.equals("sun.nio.ch.KQueueSelectorProvider")) {
return 0;
}
}
// IBM
} else if (vendor.indexOf("ibm") >= 0) {
// Linux or AIX
if (os.indexOf("linux") >= 0 || os.indexOf("aix") >= 0) {
if (version.equals("1.5") || version.matches("^1\\.5\\D.*$")) {
if (provider.equals("sun.nio.ch.PollSelectorProvider")) {
return 1;
}
} else if (version.equals("1.6") || version.matches("^1\\.6\\D.*$")) {
// IBM JDK 1.6 has different constraint level for different
// version. The exact version can be determined only by its
// build date.
Pattern datePattern = Pattern.compile(
"(?:^|[^0-9])(" +
"[2-9][0-9]{3}" + // year
"(?:0[1-9]|1[0-2])" + // month
"(?:0[1-9]|[12][0-9]|3[01])" + // day of month
")(?:$|[^0-9])");
Matcher dateMatcher = datePattern.matcher(vminfo);
if (dateMatcher.find()) {
long dateValue = Long.parseLong(dateMatcher.group(1));
if (dateValue < 20081105L) {
// SR0, 1, and 2
return 2;
} else {
// SR3 and later
if (provider.equals("sun.nio.ch.EPollSelectorProvider")) {
return 0;
} else if (provider.equals("sun.nio.ch.PollSelectorProvider")) {
return 1;
}
}
}
}
}
// BEA
} else if (vendor.indexOf("bea") >= 0 || vendor.indexOf("oracle") >= 0) {
// Linux
if (os.indexOf("linux") >= 0) {
if (provider.equals("sun.nio.ch.EPollSelectorProvider") ||
provider.equals("sun.nio.ch.PollSelectorProvider")) {
return 0;
}
// Windows
} else if (os.indexOf("windows") >= 0) {
if (provider.equals("sun.nio.ch.WindowsSelectorProvider")) {
return 0;
}
}
// Apache Software Foundation
} else if (vendor.indexOf("apache") >= 0) {
if (provider.equals("org.apache.harmony.nio.internal.SelectorProviderImpl")) {
return 1;
}
}
// Others (untested)
return -1;
}
private static final class ConstraintLevelAutodetector {
ConstraintLevelAutodetector() {
super();
}
int autodetect() {
final int constraintLevel;
ExecutorService executor = Executors.newCachedThreadPool();
boolean success;
long startTime;
int interestOps;
ServerSocketChannel ch = null;
SelectorLoop loop = null;
try {
// Open a channel.
ch = ServerSocketChannel.open();
// Configure the channel
try {
ch.socket().bind(new InetSocketAddress(0));
ch.configureBlocking(false);
} catch (Throwable e) {
logger.warn("Failed to configure a temporary socket.", e);
return -1;
}
// Prepare the selector loop.
try {
loop = new SelectorLoop();
} catch (Throwable e) {
logger.warn("Failed to open a temporary selector.", e);
return -1;
}
// Register the channel
try {
ch.register(loop.selector, 0);
} catch (Throwable e) {
logger.warn("Failed to register a temporary selector.", e);
return -1;
}
SelectionKey key = ch.keyFor(loop.selector);
// Start the selector loop.
executor.execute(loop);
// Level 0
success = true;
for (int i = 0; i < 10; i ++) {
// Increase the probability of calling interestOps
// while select() is running.
do {
while (!loop.selecting) {
Thread.yield();
}
// Wait a little bit more.
try {
Thread.sleep(50);
} catch (InterruptedException e) {
// Ignore
}
} while (!loop.selecting);
startTime = System.nanoTime();
key.interestOps(key.interestOps() | SelectionKey.OP_ACCEPT);
key.interestOps(key.interestOps() & ~SelectionKey.OP_ACCEPT);
if (System.nanoTime() - startTime >= 500000000L) {
success = false;
break;
}
}
if (success) {
constraintLevel = 0;
} else {
// Level 1
success = true;
for (int i = 0; i < 10; i ++) {
// Increase the probability of calling interestOps
// while select() is running.
do {
while (!loop.selecting) {
Thread.yield();
}
// Wait a little bit more.
try {
Thread.sleep(50);
} catch (InterruptedException e) {
// Ignore
}
} while (!loop.selecting);
startTime = System.nanoTime();
interestOps = key.interestOps();
synchronized (loop) {
loop.selector.wakeup();
key.interestOps(interestOps | SelectionKey.OP_ACCEPT);
key.interestOps(interestOps & ~SelectionKey.OP_ACCEPT);
}
if (System.nanoTime() - startTime >= 500000000L) {
success = false;
break;
}
}
if (success) {
constraintLevel = 1;
} else {
constraintLevel = 2;
}
}
} catch (Throwable e) {
return -1;
} finally {
if (ch != null) {
try {
ch.close();
} catch (Throwable e) {
logger.warn("Failed to close a temporary socket.", e);
}
}
if (loop != null) {
loop.done = true;
try {
executor.shutdownNow();
} catch (NullPointerException ex) {
// Some JDK throws NPE here, but shouldn't.
}
try {
for (;;) {
loop.selector.wakeup();
try {
if (executor.awaitTermination(1, TimeUnit.SECONDS)) {
break;
}
} catch (InterruptedException e) {
// Ignore
}
}
} catch (Throwable e) {
// Perhaps security exception.
}
try {
loop.selector.close();
} catch (Throwable e) {
logger.warn("Failed to close a temporary selector.", e);
}
}
}
return constraintLevel;
}
}
private static final class SelectorLoop implements Runnable {
final Selector selector;
volatile boolean done;
volatile boolean selecting; // Just an approximation
SelectorLoop() throws IOException {
selector = Selector.open();
}
public void run() {
while (!done) {
synchronized (this) {
// Guard
}
try {
selecting = true;
try {
selector.select(1000);
} finally {
selecting = false;
}
Set keys = selector.selectedKeys();
for (SelectionKey k: keys) {
k.interestOps(0);
}
keys.clear();
} catch (IOException e) {
logger.warn("Failed to wait for a temporary selector.", e);
}
}
}
}
public static void main(String[] args) throws Exception {
for (Entry e: System.getProperties().entrySet()) {
System.out.println(e.getKey() + ": " + e.getValue());
}
System.out.println();
System.out.println("Hard-coded Constraint Level: " + CONSTRAINT_LEVEL);
System.out.println(
"Auto-detected Constraint Level: " +
new ConstraintLevelAutodetector().autodetect());
}
private NioProviderMetadata() {
// Unused
}
}
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