Cluster Class

[ryanmrichard]

The Cluster class generalizes the concept of an MPI group.

class Cluster {
public:
// Returns some identifying name of the cluster
std::string name(); 

// The number of nodes (MPI ranks) in the cluster
size_type size();

// Is the current node in the cluster?
bool has_me();

// Get the current node
Node me();

/// Get the number of network storage places this cluster has (these are things like network filesystems
/// not node-local storage places)
size_type n_storage();

/// Gets the i-th memory space
Storage memory_space(size_type i);

// Returns node i
Node operator[](size_type i);

// Collectives originating from all members going to one point
template<template <typename> typename Container, typename OperationType>
auto reduce(Container&& data, OperationType&& op, Node destination);

template<template <typename> typename Container>
auto gather(Container&& data, Node destination);

// Collectives originating from all members going to all members
template<template <typename> typename Container, typename OperationType>
auto reduce(Container&& data, OperationType&& op, Cluster destination);

template<template <typename> typename Container>
auto gather(Container&& data, Cluster destination);

// Standard output stream (lets all nodes in this cluster print)
std::ostream stdout;

// Standard error stream
std::ostream stderr;
};

Notes:

• The actual implementation should probably create Node instances on the fly, rather than storing them.
• Stream classes will need to properly account for MPI rank