strange persistence problem

[Dave Mason]

Hi Frank,
I think I tracked this down.  I use this particular object 
programmatically (my speller doesnt seem to know how to handle that any 
better than I do), like this:

unsigned long   seqNum = 0ul;
while (running) {
   do some stuff, incremement seqNum
   wsSeqNum::instance->set_value(seqNum);
}

If you look in mib.cpp for MibLeaf::set_value(const unsigned long l), 
the first line is
set_syntax(sNMP_SYNTAX_INT32);
This apparently changes the syntax to signed integer, and it gets 
written to persistent storage that way.  Later, I get the error below 
when I try to read this back into an unsigned integer.  I believe this 
should be
set_syntax(sNMP_SYNTAX_GAUGE32);
or something similar (UINT32).

Regards,
Dave

Frank Fock wrote:

> Hi Dave,
>
> Are you sure that the syntax was Gauge32 when the object
> has been written to disk?
>
> May be the syntax had been changed accidentally by calling
> replace_value?
>
> The syntax is not checked when data is loaded, so if the
> syntax of an object changes, one has to write conversion
> routines to be able to use the old configuration files.
>
> Hope this helps.
>
> Best regards,
> Frank
>
> Dave Mason wrote:
>
>> Hi,
>> I have a problem where the syntax of an object appears to change 
>> after the persistence data is read in.  Here is a code fragment from 
>> agent.cpp.  In the MIB, wsSeqNum has SYNTAX Unsigned32, DEFVAL 0. 
>> AgentGen Pro appears to translate this to Gauge32.
>>
>>    // add supported objects
>>    init(*mib);
>>    // add user modules
>>    module_init(mib);
>>
>>    int rc;
>>    unsigned long seqNum;
>>    rc = wsSeqNum::instance->get_value(seqNum);
>>    // load persitent objects from disk
>>    mib->init();
>>    rc = wsSeqNum::instance->get_value(seqNum);
>>
>> The first get_value works fine, leaving seqNum with the initial 
>> default value of 0.  The return code rc is 0.  However, after the 
>> mib->init(), the same get_value fails because it now thinks the 
>> object syntax is a signed integer.  The return code is -10.  
>> Interestingly enough, the second get_value works if I delete the 
>> persistence data files.  Any ideas?
>>
>> Regards,
>> Dave
>>
>>