[snmp] Westhawk SNMP Stack version 5.1 stuck thread issue

[Alex Ioannou]

Hi there

I'm experiencing some problems when running SNMP requests using the
Westhawk SNMP stack, version 5.1.
Threads on the application server are becoming stuck when attempting
to clean up the SNMP context after
sending an SNMP request to a device.

We are running our application on BEA Weblogic 10 application server.
 We have an enterprise java bean
that manages our SNMP requests to the westhawk API.   The application
will send several SNMP requests
simultaneously to different devices so several SNMP context objects
will reside in memory and our application
will have the possibility of invoking the destroy method simultaneously.

I looked through the source code for version 6 and found that a fix
was made in Transmitter.java where
one thread set the "me" variable to null in destroy() but a second
would be about to call me.interrupt() in
interruptMe(), resulting in a null pointer.

Will this fix help with my stuck thread issue or is there still a
problem in the code?


	[deadlocked thread] ExecuteThread: '21' for queue: 'act-execute-queue':
	----------------------------------------------------------------------
	Thread 'ExecuteThread: '21' for queue: 'act-execute-queue'' is
waiting to acquir
	e lock 'uk.co.westhawk.snmp.stack.Transmitter at 984dea' that is held by
thread '73
	.106.72.80_161_null_v1_Trans0'

	Stack trace:
	------------
		uk.co.westhawk.snmp.stack.Transmitter.stand(Transmitter.java:144)
		uk.co.westhawk.snmp.stack.Transmitter.destroy(Transmitter.java:161)
		uk.co.westhawk.snmp.stack.AbstractSnmpContext.freeTransmitters(AbstractS
	nmpContext.java:934)
		uk.co.westhawk.snmp.stack.AbstractSnmpContext.destroy(AbstractSnmpContex
	t.java:470)
	
Thanks
Alex