Bug ID: JDK-5053708 DNS provider does not cleanup resources properly

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Other	JDK 6	JDK 7
1.4.2_15Fixed	6u2Fixed	7 b12Fixed

The DNS provider context does not cleanup the network resources
upon a close.

This problem was posted on the JNDI forum at java.sun.com

import java.net.*;
import javax.naming.*;
import javax.naming.directory.*;
import java.util.*;

public class SocketLeak {
    public static void main(String argv[]) throws Exception {
        Map map = new HashMap();
        Hashtable env= new Hashtable();

        env.put(Context.INITIAL_CONTEXT_FACTORY,
                "com.sun.jndi.dns.DnsContextFactory");
        env.put(Context.PROVIDER_URL,"dns://xxx.xxx.xxx.xxx");
        int count = 0;

        while(true) {
            DirContext ctx = new InitialDirContext(env);
            ctx.close();
            ctx = null;
            count++;
            System.out.println(count);
        }
    }
}


The above program loops for around 1020 times on solaris 8, after which it runs
out of file descriptors, and fails with an exception below.

Exception in thread "main" javax.naming.ConfigurationException.  Root exception is java.net.SocketException: Too many open files
        at java.net.PlainDatagramSocketImpl.datagramSocketCreate(Native Method)
        at java.net.PlainDatagramSocketImpl.create(PlainDatagramSocketImpl.java:53)
        at java.net.DatagramSocket.createImpl(DatagramSocket.java:278)
        at java.net.DatagramSocket.<init>(DatagramSocket.java:127)
        at com.sun.jndi.dns.DnsClient.<init>(DnsClient.java:81)
        at com.sun.jndi.dns.Resolver.<init>(Resolver.java:33)
        at com.sun.jndi.dns.DnsContext.<init>(DnsContext.java:78)
        at com.sun.jndi.dns.DnsContextFactory.UrlToContext(DnsContextFactory.java:73)
        at com.sun.jndi.dns.DnsContextFactory.getInitialContext(DnsContextFactory.java:41)
        at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:662)
        at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:243)
        at javax.naming.InitialContext.init(InitialContext.java:219)
        at javax.naming.InitialContext.<init>(InitialContext.java:195)
        at javax.naming.directory.InitialDirContext.<init>(InitialDirContext.java:80)
        at SocketLeak.main(SocketLeak.java:17)

SUGGESTED FIX --- DnsContext.java Thu Mar 29 13:53:55 2007 *** 123,135 **** retries = ctx.retries; lookupCT = ctx.lookupCT; } public void close() { ! // When adding anything here, consider whether BindingEnumeration ! // needs a finalizer. } //---------- Environment operations /* --- 123,137 ---- retries = ctx.retries; lookupCT = ctx.lookupCT; } public void close() { ! if (resolver != null) { ! resolver.close(); ! resolver = null; } + } --- Resolver.java Thu Mar 29 13:54:25 2007 *** 44,53 **** --- 44,54 ---- dnsClient = new DnsClient(servers, timeout, retries); } public void close() { dnsClient.close(); + dnsClient = null; }

03-05-2007

EVALUATION See comments

02-09-2004

Duplicate :	JDK-6519688 - DNS provider does not cleanup resources properly
Relates :	JDK-6585239 - Regression: 2 DNS tests fail with JDK 5.0u13 b01 and pass with 5.0u12fcs
Relates :	JDK-6806783 - Regression : NullPointerException comes to occur in 1.4.2_15 - 1.4.2_20