Re: dynamic sql - receive fetched row values into host variables

On 2017-10-19 9:49 AM, dlclark@xxxxxxxxxxxxxxxx wrote:

...          The handler is in memory for the call from the second program and
apparently has some variables also in memory that aren't getting
reinitialized for each call.  That is also why RCLRSC works -- because it
forces the handler out of memory so that it gets new storage for its
variables when it is loaded again.  The solution is to make sure global
variable storage is reinitialized when either the calling program or
requested file changes.

Another way to handle multiple files is to use the "state info" mechanism to have a separate set of "global" data for each file. It would be necessary to use this mechanism if it was possible that a program with an OA file might call another program with an OA file, so the calls to the handler would be interleaved.

Create a data structure template with a subfield for each global variable. Then, while handling the open for the file, allocate the storage for the basing pointer of a "globals" based data structure and initialize the subfields, and also put the pointer in the stateInfo pointer of the handler parameter. On subsequent calls to the handler, use the stateInfo pointer to set the basing pointer for a based "globals" data structure.

dcl-ds globals_t qualified template;
   something char(1);
   whatever int(10);
end-ds;
dcl-ds globals likeds(globals_t) based(pGlobals);

   if parm.rpgOperation = QrnOperation_OPEN;
      // allocate globals for this file
      pGlobals = %alloc(%size(globals_t));
      parm.stateInfo = pGlobals;
      // initialize globals for this file
      globals.something = 'x';
      globals.whatever = 5;
   elseif parm.rpgOperation = QrnOperation_CLOSE;
      pGlobals = parm.stateInfo;
      ... do regular close stuff
      dealloc(n) parm.stateInfo;
      pGlobals = *null;
   elseif .... ;  // some other operation
      pGlobals = parm.stateInfo;
   ...