Coding Guidelines¶

Error Handling / Exceptions¶

• Use a common rsb::Exception for all exceptions
  • In languages where multiple inheritance is a pain, this class inherits from a runtime-like error and a custom exception tree with e.g. InvalidArgument is created underneath this root exception type.
  • If multiple inheritance is feasible, use it to reuse the existing language exception types.
• in C++, don't use exceptions in constructors if you have objects that need a manual deallocation (to be verified that the destructor is not called for half-constructed instances)

Barricade Strategy¶

• Generally user-induced data should be validated on the client level.
• Exception to this rule is the converter mechanism -> user data member of the event class
  • Generally performing a validation already in client-level code is too expensive
  • OutRoute:
    • Always using exceptions in the sending stack is not possible for asynchronous sending strategies.
    • An invalid combination of data and converter is a (user-induced) fatal error
    • exit the program (using a macro/function that creates a segfault in any case to get a backtrace, assert could be switched off and the error would be unnoticed or untraceable)
  • InRoute:
    • two cases:
      1. no converter available:
         • Could happen because the receiver is not the cause of the message
         • for Reader (pull-based model) an exception is possible without any problems
         • Asynchronous case requires user checking for exceptions:
           • Special event or tag in event for error condition
           • A method for the user to check whether the event is an error condition or not
      2. Error while converting