[SNMP4J] Null Pointer Exception in DefaultTcpTransportMapping.close()

[Prusi, Jesse R]

Frank,

Thanks for the quick fix.  I tried it with version 1.7.4 and it's still
not working.  When I call close on the snmp object and subsequently the
DefaultTcpTransportMapping close method is invoked, it is hanging on the
server.join() call.  I put in some debug and it looks like the lock on
the transport mapping object is never being free so the server object
never gets set to null at the end of the ServerThread run() method.

Thanks,
Jesse

-----Original Message-----
From: Frank Fock [mailto:fock at agentpp.com] 
Sent: Thursday, August 17, 2006 12:24 PM
To: Frank Fock
Cc: Prusi, Jesse R; snmp4j at agentpp.org
Subject: Re: [SNMP4J] Null Pointer Exception in
DefaultTcpTransportMapping.close()

Hi,

SNMP4J v1.7.4 can now be downloaded from http://www.snmp4j.org.
This version should fix the below described problem.
Please let me know if you still encounter problems anyway!

Best regards,
Frank

Frank Fock wrote:
> I expect the fix to be available later today.
> I will post it here when it has been uploaded.
> 
> Best regards,
> Frank
> 
> Prusi, Jesse R wrote:
>> Thanks for the response Frank.  Do you have an estimate on when you
will
>> have the fix tested?  Can you please provide a patch when you have it
>> ready so I won't have to wait for the next release?
>>
>> Thanks,
>> Jesse
>>
>> -----Original Message-----
>> From: Frank Fock [mailto:fock at agentpp.com] Sent: Wednesday, August
16, 
>> 2006 12:20 AM
>> To: Prusi, Jesse R
>> Cc: snmp4j at agentpp.org
>> Subject: Re: [SNMP4J] Null Pointer Exception in
>> DefaultTcpTransportMapping.close()
>>
>> Hi Jesse,
>>
>> I am working on this. My current approach synchronizes
>> the access to the "server" member. I have to test if
>> it works now...
>>
>> Best regards,
>> Frank
>>
>> Prusi, Jesse R wrote:
>>> Upon further investigation this fix did not solve the problem.  The
>>> sockets are still not getting closed.  Any ideas?
>>>
>>> Thanks,
>>> Jesse
>>>
>>> -----Original Message-----
>>> From: snmp4j-bounces at agentpp.org [mailto:snmp4j-bounces at agentpp.org]
>> On
>>> Behalf Of Prusi, Jesse R
>>> Sent: Tuesday, August 15, 2006 7:27 AM
>>> To: snmp4j at agentpp.org
>>> Subject: RE: [SNMP4J] Null Pointer Exception in
>>> DefaultTcpTransportMapping.close()
>>>
>>> I updated the close() method to catch the NPE when join() is called
>> and
>>> the server thread has already been set to null because run() exited.
>>> This allows the sockets to be closed so the ports are freed up and
it
>>> seems to fix the problem.  Anyone else have a better solution?
>>>
>>>
>>>   /**
>>>    * Closes all open sockets and stops the internal server thread
that
>>>    * processes messages.
>>>    */
>>>   public synchronized void close() {
>>>     if (server != null) {
>>>       server.close();
>>>       try {
>>>         server.join();
>>>       }
>>>       catch (NullPointerException npe) {
>>>         logger.warn(npe);
>>>       }
>>>       catch (InterruptedException ex) {
>>>         logger.warn(ex);
>>>       }
>>>       server = null;
>>>       for (Iterator it = sockets.values().iterator(); it.hasNext();
)
>> {
>>>         SocketEntry entry = (SocketEntry)it.next();
>>>         try {
>>>           synchronized (entry) {
>>>              entry.getSocket().close();
>>>           }
>>>           logger.debug("Socket to "+entry.getPeerAddress()+"
closed");
>>>         }
>>>         catch (IOException iox) {
>>>           // ingore
>>>           logger.debug(iox);
>>>         }
>>>       }
>>>       if (socketCleaner != null) {
>>>         socketCleaner.cancel();
>>>       }
>>>       socketCleaner = null;
>>>     }
>>>   }
>>>
>>> Thanks,
>>> Jesse
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: snmp4j-bounces at agentpp.org [mailto:snmp4j-bounces at agentpp.org]
>> On
>>> Behalf Of Prusi, Jesse R
>>> Sent: Monday, August 14, 2006 6:44 PM
>>> To: snmp4j at agentpp.org
>>> Subject: [SNMP4J] Null Pointer Exception in
>>> DefaultTcpTransportMapping.close()
>>>
>>> Hello,
>>>
>>> I'm using SNMP4J 1.7.3 on a Windows XP machine.
>>>
>>> I find a get a Null Pointer Exception when snmp.close().  Here is my
>>> sample code:
>>>
>>> public class SnmpTest {
>>>
>>>     public static void main(String[] args) {
>>>         try{
>>>             DefaultTcpTransportMapping myTransport = new
>>> DefaultTcpTransportMapping(
>>>                     new
>>> TcpAddress(InetAddress.getLocalHost(),
>>>                             10163));
>>>             myTransport.setMaxInboundMessageSize(1400);
>>>             myTransport.setConnectionTimeout(1000);
>>>            
>>>             Snmp snmp = new Snmp(myTransport);
>>>             OctetString localEngineId = new
>>> OctetString(MPv3.createLocalEngineID());
>>>             USM usm = new
>>> USM(SecurityProtocols.getInstance(), localEngineId, 0);
>>>     
>>> SecurityModels.getInstance().addSecurityModel(usm);
>>>             snmp.listen();
>>>             System.out.println("Listening on port 10163");
>>>             for(int i=0; i < 10000; i++){
>>>                 System.out.println("spinning " + i);
>>>             }
>>>             snmp.close();
>>>             System.out.println("Closed Snmp Session");
>>>         }
>>>         catch(Exception e){
>>>             e.printStackTrace();
>>>         }
>>>     }
>>> }
>>>
>>> I get the following stack trace:
>>>
>>> java.lang.NullPointerException
>>>     at
>>>
>>
org.snmp4j.transport.DefaultTcpTransportMapping.close(DefaultTcpTranspor
>>> tMapping.java:186)
>>>     at org.snmp4j.Snmp.close(Snmp.java:429)
>>>     at SnmpTest.main(SnmpTest.java:31)
>>>
>>> The NPE does not occur if I comment out the spinning for loop.  I
>>> thought this might have something to do with the timeout setting of
>> the
>>> TCP transport mapping, but I still get the error after increasing
the
>>> timeout to 10000.  Any ideas why this is occurring?  Am I using the
>> TCP
>>> transport mapping incorrectly?
>>>
>>> Thanks, 
>>> Jesse Prusi
>>>
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>>>
>>>
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>>
> 

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