snmpwalk in a threaded agent

[Nakamura, James]

I'm still working my way through getting my agent to work with an snmpwalk.
The setup is a process talking via a tcp
socket to my agent (using the agent++ library). I have it set up with
threads to handle the fact that data is being
passed asynchronously through the tcp socket. Anyway, when I do a snmpwalk,
it gets through all of the snmp
oids, but when it hits the first mib object that I create, it (or something)
gets confused: the logs indicate that 
the data that needed to be exchanged between the process and the agent
occured correctly, with the following
sequence is logged (meccmib is the derived mib object):

20010227.16:15:13: 01493: (2)EVENT  : RequestList: request received
(id)(siz)(fro)(ver)(com): (1567562870), (1), (206.64.210.9/48262), (SNMPv1),
(public).
20010227.16:15:13: 01493: (6)EVENT  : main: GOT MIB REQUEST.
20010227.16:15:13: 01527: (2)EVENT  : Agent: starting thread execution.
20010227.16:15:13: 01527: (2)EVENT  : Mib: process request: getnext request,
oid: (30), (1.3.6.1.2.1.11.32.0).
20010227.16:15:13: 01527: (3)EVENT  : Mib: process subrequest: getnext
request, oid: (30), (1.3.6.1.2.1.11.32.0).
20010227.16:15:13: 01527: (6)EVENT  : meccmib(get_request)::
(MCDN.MCDN.REG_COUNT).
20010227.16:15:13: 01527: (6)EVENT  : DataFromProcess: got data: :
(VMCDN.MCDN.REG_COUNT=0	), (23).
20010227.16:15:13: 01527: (6)EVENT  : DataFromProcess:MibData::
(MCDN.MCDN.REG_COUNT=0).
20010227.16:15:13: 01527: (6)EVENT  : DataFromProcess:calling handle
request.
20010227.16:15:13: 01527: (6)EVENT  : meccmib(handle_request from meccano)::
(MCDN.MCDN.REG_COUNT=0).
20010227.16:15:13: 01527: (3)EVENT  : RequestList: finished subrequest::
(0), (1.3.6.1.4.1.1102.1.3.6.30), (0).
20010227.16:15:13: 01527: (2)EVENT  : RequestList: answer request: (30).
20010227.16:15:13: 01527: (4)EVENT  : RequestList: request answered:
(1567562870), (30), (206.64.210.9/48262), (0), (0).
20010227.16:15:13: 01527: (1)ERROR  : RequestList: done: can't find request
id: (30).
20010227.16:15:13: 01527: (2)EVENT  : Agent: finished thread execution.

The disturbing line is the "can't find request id" which implies that the
request object got blasted along the way. 
It's interesting to note that the "request answered" deletes the request
after the conclusion which probably is
the reason why the request is no longer available. Why is the library now
trying to access an object that appears
to have been freed? Is there something amiss in the way I built my mib
objects (and placed them into the tree)?

The effect is that the snmpwalk only gets to the snmp data and then stops
without getting any of the process
specific data. Any ideas what's going on here? 

James Nakamura
naka at metricom.com
Work like you don't need the money. Love like you've never been hurt. Dance
like nobody is watching. -- Mark Twain