Charm++ parallel programming system

[Robert Steinke <rsteinke AT uwyo.edu>]

I have a general question about the design of some code I'm writing.  
I've got a situation with some Charm++ messages and some C++ 
inheritance.  Basically, I just want to get anyone's impression if 
there's a better way to do it than what I'm currently doing.

In my .ci file I have a chare array and some code like this:


thisProxy[some other array element].sendNeighborAttributes(some data);

...

when sendNeighborAttributes(const std::vector<NeighborMessage>& messages) {
  serial { receiveMessages(messages); }
}

...

thisProxy[some other array element].sendState(some data);

...

when sendState(const std::vector<StateMessage>& messages) {
  serial { receiveMessages(messages); }
}

...

thisProxy[some other array element].sendWater(some data);

...

when sendWater(const std::vector<WaterMessage>& messages) {
  serial { receiveMessages(messages); }
}


The thing is, NeighborMessage, StateMessage, and WaterMessage all 
inherit from a common base class.  When I receive a message I do the 
same thing for all three.  I hand the message to a contained class, and 
that class figures out polymorphically what to do with it. That's why I 
call the same receiveMessages function in all three cases.  But I still 
have nearly-duplicated code in the .ci file.

My first question is can I combine the three when clauses in the .ci 
file into one?  I think I might need them to have separate signatures 
because it needs to pup a vector of WaterMessage, not a vector of the 
base class.

My second question relates to the receiveMessages function.  It looks 
like this:

template <typename T> inline void receiveMessages(std::vector<T>& 
messages) {
    typename std::vector<T>::iterator it; // Loop iterator.

    // Loop over messages calling receiveMessage for each one.
    for (it = messages.begin(); it != messages.end(); ++it) {
        receiveMessage(*it);
    }
}

void receiveMessage(Message& message);

The only way I could get it working was to make receiveMessages a 
template function.  I'd rather have it be a polymorphic function taking 
the base class.  Notice that once I have a single message instead of a 
vector of them I can call a polymorphic function on the single object.  
I guess std::vector<SubClass> isn't a subclass of 
std::vector<SuperClass>.  I suppose this is really more of a C++ 
question than a Charm++ question, but is there any better way to do this?

Thanks for any help.  This is not urgent.  I have code that works. I'm 
just trying to improve my Charm++-Fu

Bob Steinke