RE: Pointer or Parameter Error... -- RPG400-L

Hi Tommy,

The failing point was due to the GetOSInfo() procedure in the service
program.  I restructed the procedure to return a varying field (in this
case the BasicInfo DS)

It's because you're writing blanks into 31434 bytes of memory that don'tbelong to you. As luck would have it, you seem to be accidentally hittingthe area of memory where the system stores the indicator that keeps trackof whether a file is open.


Who knows what else you're corrupting!

Here's where you're calling GetOsInfo():

         // Get OS/400 Information From The User's Profile

          GetOSInfo( BasicInfo
                   : %Size(BasicInfo)
                   : 'USRI0300'
                   : Kr_SxUser
                   : Successful);

The first parameter is BasicInfo, which is defined as a data structurethat's 1333 bytes long. Here's the PI for the GetOsInfo proc:


     pGetOSInfo        B                   Export
     d GetOSInfo       PI
     d  ReturnData                32767a   Options(*VarSize)
     d  ReturnLength                 10i 0 Const
     d  Format                        8a   Const
     d  UserProfile                  10a   Const
     d  Successful                     n

Note that in this place, you've defined the first parameter as 32767 byteslong. Later in this procedure, you do the following:


         ReturnData = BasicInfo;

OOps... now you've made a mess of things. This statement doesn't justset the first 1333 bytes of ReturnData! It sets the first 1333 bytes tomatch what's in the BasicInfo data structure, and sets the other 31434bytes to blanks.

Unfortunately, ReturnData doesn't have any memory declared for it. It'susing the memory of the BasicInfo data structure from the calling module!And that's only 1333 bytes long.

That's, ostensibly, why you're passing the ReturnLength parameter. Sothat you know how much space the caller has allocated to the ReturnDataparameter -- but you're not using ReturnLength anywhere!


The fix should be to change that statement to read as follows:

         %subst(ReturnData:1:ReturnLength) = BasicInfo;

That will prevent it from corrupting memory. Assuming you're not doingthe same thing somewhere else, your problem should be solved.

Please remember to be very, very, very careful whenever you useOPTIONS(*VARSIZE).

program KR0057EX & it works fine now.  Should this be reported to IBM???
What's your opinion??


No, this is clearly a bug in your code, not IBM's.