--- Begin Message ---
- To: Debian Bug Tracking System <submit@bugs.debian.org>
- Subject: libgcj4: ServerSocketChannel causes Selector.select() to return immediatly.
- From: Sebastian Andersson <sa@hogia.net>
- Date: Sun, 28 Mar 2004 01:14:48 +0100
- Message-id: <20040328001529.82B6A37E4F@smtp2-1-sn4.m-sp.skanova.net>
Package: libgcj4
Version: 1:3.3.3-5
Severity: normal
If a ServerSocketChannel has been registered for SelectionKey.OP_ACCEPT
at a Selector, select() will return immediatly with OP_ACCEPT on that
Channel, even when there is no connection waiting.
See example:
Server.java:
-------------------------8<---------------------------------------------
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
public class Server {
public static void main(String[] args) {
try {
Selector serverSelector = Selector.open();
ServerSocketChannel ssc = ServerSocketChannel.open();
ssc.configureBlocking(false);
ssc.socket().bind(new InetSocketAddress(2003));
ssc.register(serverSelector, SelectionKey.OP_ACCEPT);
while(true) {
System.out.println("Before selector");
while(serverSelector.select() > 0) {
System.out.println("Something was selected.");
java.util.Set readyKeys = serverSelector.selectedKeys();
Iterator iter = readyKeys.iterator();
while(iter.hasNext()) {
SelectionKey key = (SelectionKey)iter.next();
iter.remove();
if(key.isAcceptable()) {
ServerSocketChannel ssc2 = (ServerSocketChannel)key.channel();
System.out.println("Before accept.");
Socket socket = ssc2.socket().accept();
System.out.println("After accept.");
socket.getOutputStream().write("Hello World!\r\n".getBytes());
socket.close();
}
}
}
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
}
-------------------------8<---------------------------------------------
Compile and run it with:
gcj-3.3 --main=Server Server.java && ./a.out
and it will output:
Before selector
Something was selected.
Before accept.
and hang in the ServerSocket.accept() method until a connection
happens.
-- System Information:
Debian Release: testing/unstable
APT prefers testing
APT policy: (990, 'testing'), (500, 'unstable')
Architecture: i386 (i686)
Kernel: Linux 2.4.20-xfs
Locale: LANG=sv_SE, LC_CTYPE=sv_SE
Versions of packages libgcj4 depends on:
ii libc6 2.3.2.ds1-11 GNU C Library: Shared libraries an
ii libgcc1 1:3.3.3-1 GCC support library
ii libgcj-common 1:3.3.3-1 Java runtime library (common files
ii libstdc++5 1:3.3.3-1 The GNU Standard C++ Library v3
ii xlibs 4.2.1-12.1 X Window System client libraries
ii zlib1g 1:1.2.1-5 compression library - runtime
-- no debconf information
--- End Message ---