Supermpi Interface

class TLoadBalancer
{
public:
    TLoadBalancer();
        // Create a load balancer, which will crash if you try to use it
        // before calling SetComm()

    ~TLoadBalancer();
        // Deletes some heap memory

    void SetComm(MPI_Comm comm);
        // Perform necessary initialisation tasks. Initially, each node will
        // get an equal amount of the task in DivideTask().

    template <class T> pair<T, T> DivideTask(T start, T end);
        // Divides up a task described by some sort of loop counter. Returns a
        // pair describing the start and end of the task, which is dependent on
        // the node. T must have all the usual arithmetic operators. Does not
        // require any communication.

    void StartClock();
        // Start timing a task which has been split up by DivideTask()

    void StopClock();
        // Stop timing. Communicate between processes so that every process 
        // knows how fast all the other processors are.
};


//-------------------------------------------------------------------------
// The value type "T" must have ++ and += operators, must have a constructor
// from 0, and must be laid out nicely in memory so it can be transmitted to
// another computer using &t and sizeof(T).

template <class T>
class TIncr
{
public:
    TIncr();
        // Create an incrementor, initialised to zero

    TIncr(T data_);
        // Starts it off on some value. For example, if you start it on the
        // constant 1, calling Flush() immediately will return the number of nodes.

    TIncr<T> & operator++();
        // Increments

    TIncr<T> & operator+=(T other);
        // Also increments, just by a variable amount

    T Flush(MPI_Comm comm);
        // Broadcasts the data value to all processes, and returns the
        // updated value.

    operator T() {return data;}
        // Cast to type T

    T data;
};

TLoadBalancer loadBalancer;
loadBalancer.SetComm(MPI_COMM_WORLD);

MPIFOR(i, 1, 1000) {
    printf("Look at me, I can print 1000 lines really fast!\n");
} END_MPIFOR

MPIFOR_64(i, 1, 1000000000000LL) {
    printf("I wonder how big that PBS spool can get?\n");
} END_MPIFOR