Use case: INCO procedure without asynchronous part

INOS code

Assume registered function on INOS that has no asynchronous execution part. It just returns a value than can be received by the PC code.

uint32 CMyModule::eGetValue()
{
    return 69;
}

PC code

Let's have a look at different use cases from PC code point of view, how to call the previously mentioned INOS function.

Correct usage

• Preferred solution 1: Use CallProcedureExSync

  double dResult = 0.0;
  uint32 uError = CallProcedureExSync("TargetName", "PathToProcedure.GetValue()", &dResult);
  if( uError == ER_INCO_NO_ERROR ) {
      // ok, calling the procedure succeeded!
      cout << "Value is: " << dResult << endl;
  } else {
      // error occurred
  }

• Preferred solution 2: Call the procedure by getting the return value:

  double dResult = 0.0;
  int32 iTicketOrError = CallProcedureEx("TargetName", "PathToProcedure.GetValue()", &dResult);
  if( iTicketOrError == ER_INCO_NO_ERROR ) {
      // ok, calling the procedure succeeded!
      cout << "Value is: " << dResult << endl;
  } else {
      // INCO error occurred
  }
  // note: iTicketOrError will for sure not be negative because the function has no asynchronous part

• Another possiblity: Use the 'old-style' CallProcedure:

  double dResult = 0.0;
  uint32 uError = CallProcedure("TargetName", "PathToProcedure.GetValue()", &dResult);
  if( uError == ER_INCO_NO_ERROR ) {
      // ok, calling the procedure succeeded!
      cout << "Value is: " << dResult << endl;
  } else {
      // INCO error occurred
  }

Strange (but valid) usage

• Calling the function but ignore the returned value (which is 69 in this example)

  uint32 uError = CallProcedureExSync("TargetName", "PathToProcedure.GetValue()");
  if( uError == ER_INCO_NO_ERROR ) {
      // ok, calling the procedure succeeded!
  } else {
      // error occurred
  }

  int32 iTicketOrError = CallProcedureEx("TargetName", "PathToProcedure.GetValue()");
  if( iTicketOrError == ER_INCO_NO_ERROR ) {
      // ok, calling the procedure succeeded! But: We didn't get the value...
  } else {
      // INCO error occurred
  }
  // note: iTicketOrError will for sure not be negative because the function has no asynchronous part

Forbidden/invalid usage

• It's not possible to get the result of a synchronously executed procedure after the call to CallProcedureEx. Therefore, in the following use case, the second call to CallProcedureExResult will for sure return an error (mainly because iTicketOrError is not a (valid) ticket):

  int32 iTicketOrError = CallProcedureEx("TargetName", "PathToProcedure.GetValue()");
  if( iTicketOrError == ER_INCO_NO_ERROR ) {
      // ok, calling the procedure succeeded!
      double dResult;
      uint32 uError = CallProcedureExResult("TargetName", iTicketOrError, &dResult); // ===> BAD IDEA: uError will for sure be set!
  } else {
      // INCO error occurred
  }