我有一个服务器,为flash客户端安全接受请求提供服务。它只发送一个数据包,没有什么更多,但有能力容纳超过10000个并发连接?如果有的话,可能是65534。
无论如何,在24小时内为21万多个用户提供服务之后,内存使用量从12000MB上升到了74000MB。我想它会稳定下来,并继续思考,也许它的一些东西,得到了开箱登记,将被重新使用。但48小时后,它高达90MB,以这种速度,我将不得不每2天重新启动服务器,以防止OutOfMemoryException(还没有得到它,但我知道我会得到它只有300MB的内存备用)。
不管怎样,如果有人有任何时间,愿意帮助我,我真的很感激,这是来源。
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CodingErrorAction;
import java.nio.channels.CancelledKeyException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.channels.spi.SelectorProvider;
import java.util.*;
public class PolicyServer implements Runnable {
public static final String POLICY_REQUEST = "<policy-file-request/>";
public static final String POLICY_XML =
"<?xml version=\"1.0\"?>"
+ "<cross-domain-policy>"
+ "<allow-access-from domain=\"*\" to-ports=\"*\" />"
+ "</cross-domain-policy>"
+ (char)0;
// The host:port combination to listen on
private InetAddress hostAddress;
private int port;
// The channel on which we'll accept connections
private ServerSocketChannel serverChannel;
// The selector we'll be monitoring
private Selector selector;
// The buffer into which we'll read data when it's available
private ByteBuffer readBuffer = ByteBuffer.allocate(255);
// This decodes raw bytes into ascii data.
private CharsetDecoder asciiDecoder;
// A list of PendingChange instances
private List<ChangeRequest> pendingChanges = new LinkedList<ChangeRequest>();
// Maps a SocketChannel to a list of ByteBuffer instances
private Map<SocketChannel, List<ByteBuffer>> pendingData = new HashMap<SocketChannel, List<ByteBuffer>>();
public PolicyServer(InetAddress hostAddress, int port) throws IOException {
this.hostAddress = hostAddress;
this.port = port;
this.selector = this.initSelector();
this.asciiDecoder = Charset.forName("US-ASCII").newDecoder().onMalformedInput(
CodingErrorAction.REPLACE).onUnmappableCharacter(
CodingErrorAction.REPLACE);
}
public void send(SocketChannel socket, byte[] data) {
synchronized (this.pendingChanges) {
// Indicate we want the interest ops set changed
this.pendingChanges.add(new ChangeRequest(socket, ChangeRequest.CHANGEOPS, SelectionKey.OP_WRITE));
// And queue the data we want written
synchronized (this.pendingData) {
List<ByteBuffer> queue = (List<ByteBuffer>) this.pendingData.get(socket);
if (queue == null) {
queue = new ArrayList<ByteBuffer>();
this.pendingData.put(socket, queue);
}
queue.add(ByteBuffer.wrap(data));
}
}
// Finally, wake up our selecting thread so it can make the required changes
this.selector.wakeup();
}
public void run() {
while (true) {
try {
// Process any pending changes
synchronized (this.pendingChanges) {
Iterator changes = this.pendingChanges.iterator();
while (changes.hasNext()) {
ChangeRequest change = (ChangeRequest) changes.next();
if(change == null) continue;
switch (change.type) {
case ChangeRequest.CHANGEOPS:
SelectionKey key = change.socket.keyFor(this.selector);
try {
if(key!=null)
key.interestOps(change.ops);
} catch(Exception ex) {
if (key!=null)
key.cancel();
}
}
}
this.pendingChanges.clear();
}
// Wait for an event one of the registered channels
this.selector.select();
// Iterate over the set of keys for which events are available
Iterator selectedKeys = this.selector.selectedKeys().iterator();
while (selectedKeys.hasNext()) {
SelectionKey key = (SelectionKey) selectedKeys.next();
selectedKeys.remove();
if (!key.isValid()) {
continue;
}
// Check what event is available and deal with it
if (key.isAcceptable()) {
this.accept(key);
} else if (key.isReadable()) {
this.read(key);
} else if (key.isWritable()) {
this.write(key);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
private void accept(SelectionKey key) throws IOException {
// For an accept to be pending the channel must be a server socket channel.
ServerSocketChannel serverSocketChannel = (ServerSocketChannel) key.channel();
// Accept the connection and make it non-blocking
SocketChannel socketChannel = serverSocketChannel.accept();
Socket socket = socketChannel.socket();
socketChannel.configureBlocking(false);
// Register the new SocketChannel with our Selector, indicating
// we'd like to be notified when there's data waiting to be read
// also contains a attachment of a new StringBuffer (for storing imcomplete/multi packets)
socketChannel.register(this.selector, SelectionKey.OP_READ, new StringBuffer());
}
private void read(SelectionKey key) throws IOException {
SocketChannel socketChannel = (SocketChannel) key.channel();
// Clear out our read buffer so it's ready for new data
this.readBuffer.clear();
// Attempt to read off the channel
int numRead;
try {
numRead = socketChannel.read(this.readBuffer);
} catch (IOException e) {
// The remote forcibly closed the connection, cancel
// the selection key and close the channel.
key.cancel();
socketChannel.close();
return;
}
if (numRead == -1) {
// Remote entity shut the socket down cleanly. Do the
// same from our end and cancel the channel.
key.channel().close();
key.cancel();
return;
}
// Grab the StringBuffer we stored as the attachment
StringBuffer sb = (StringBuffer)key.attachment();
// Flips the readBuffer by setting the current position of
// packet stream to beginning.
// Append the data to the attachment StringBuffer
this.readBuffer.flip();
sb.append(this.asciiDecoder.decode(this.readBuffer).toString());
this.readBuffer.clear();
// Get the policy request as complete packet
if(sb.indexOf("\0") != -1) {
String packets = sb.substring(0, sb.lastIndexOf("\0")+1);
sb.delete(0, sb.lastIndexOf("\0")+1);
if(packets.indexOf(POLICY_REQUEST) != -1)
send(socketChannel, POLICY_XML.getBytes());
}
}
private void write(SelectionKey key) throws IOException {
SocketChannel socketChannel = (SocketChannel) key.channel();
synchronized (this.pendingData) {
List queue = (List) this.pendingData.get(socketChannel);
// Write until there's not more data ...
while (!queue.isEmpty()) {
ByteBuffer buf = (ByteBuffer) queue.get(0);
try {
socketChannel.write(buf);
if (buf.remaining() > 0) {
// ... or the socket's buffer fills up
break;
}
} catch(IOException e) {
// The remote forcibly closed the connection, cancel
// the selection key and close the channel.
key.cancel();
socketChannel.close();
return;
}
queue.remove(0);
}
if (queue.isEmpty()) {
// We wrote away all data, so we're no longer interested
// in writing on this socket. Switch back to waiting for
// data.
try {
if (key!=null)
key.interestOps(SelectionKey.OP_READ);
} catch(Exception ex) {
if (key!=null)
key.cancel();
}
}
}
}
private Selector initSelector() throws IOException {
// Create a new selector
Selector socketSelector = SelectorProvider.provider().openSelector();
// Create a new non-blocking server socket channel
this.serverChannel = ServerSocketChannel.open();
serverChannel.configureBlocking(false);
// Bind the server socket to the specified address and port
InetSocketAddress isa = new InetSocketAddress(this.hostAddress, this.port);
serverChannel.socket().bind(isa);
// Register the server socket channel, indicating an interest in
// accepting new connections
serverChannel.register(socketSelector, SelectionKey.OP_ACCEPT);
return socketSelector;
}
public static void main(String[] args) {
try {
new Thread(new PolicyServer(null, 5556)).start();
} catch (IOException e) {
e.printStackTrace();
}
}
}
这是ChangeRequest类
import java.nio.channels.SocketChannel;
public class ChangeRequest {
public static final int REGISTER = 1;
public static final int CHANGEOPS = 2;
public SocketChannel socket;
public int type;
public int ops;
public ChangeRequest(SocketChannel socket, int type, int ops) {
this.socket = socket;
this.type = type;
this.ops = ops;
}
}
