vt::collective::tree::Tree struct
#include <src/vt/collective/tree/tree.h>

General interface for storing a spanning tree.

Holds the portion of a spanning tree on each node. Does not do any parallel coordination. Higher-level components must keep track of the pieces of the tree on each node.

Derived classes

struct vt::collective::barrier::Barrier virtual: Perform a collective barrier that is safe to use with VT handlers in flight.
struct vt::collective::reduce::Reduce virtual: A specific, isolated reducer instance for a given scope that sequences reduce operations via the reduction stamp within that scope.
struct vt::collective::scatter::Scatter virtual: Scatter data across all nodes from a single origin.
struct vt::term::TerminationDetector: Detect global termination and of subsets of work.

Public types

using NodeListType = std::vector<NodeType>
using OperationType = std::function<void(NodeType)>
using NumLevelsType = int32_t

Constructors, destructors, conversion operators

Tree(DefaultTreeConstructTag) explicit: Construct the default spanning tree across the whole communicator.
Tree(NodeListType const& in_children) explicit: Construct a spanning tree with a list of children nodes on the root node.
Tree(bool const in_is_root, NodeType const& parent, NodeListType const& in_children): Construct a spanning tree with a list of children nodes, parent node, and whether this is the root.

Public functions

void setupTree(): Setup the default (binomial) tree.
auto getParent() const -> NodeType: Get the parent node in the tree.
auto getNumChildren() const -> NodeType: Get the number of children nodes.
auto isRoot() const -> bool: Get whether this node is the root.
auto getChildren() const -> NodeListType const &: Get the (const) list of children.
auto getChildren(NodeType node) const -> NodeListType: Get the list of children for a particular node in the tree.
void foreachChild(OperationType op) const: Apply function (foreach) across all children.
auto numLevels() const -> NumLevelsType: Get number of levels in the tree.
void foreachChild(NumLevelsType level, OperationType op) const: Apply function (foreach) across all children with number of levels passed to apply function.
auto getNumDescendants(NodeType child) const -> std::size_t: Get total number of descendants for a particular node in the tree.
auto getNumDescendants() const -> std::size_t: Get total number of descendants in the tree.

Function documentation

vt::collective::tree::Tree::Tree(NodeListType const& in_children) explicit

Construct a spanning tree with a list of children nodes on the root node.

Parameters
in_children in	the list of children

vt::collective::tree::Tree::Tree(bool const in_is_root, NodeType const& parent, NodeListType const& in_children)

Construct a spanning tree with a list of children nodes, parent node, and whether this is the root.

Parameters
in_is_root in	if this is the root node
parent in	the node's parent in the tree
in_children in	the list of children

NodeType vt::collective::tree::Tree::getParent() const

Get the parent node in the tree.

Returns	the parent node

NodeType vt::collective::tree::Tree::getNumChildren() const

Get the number of children nodes.

Returns	the number of children nodes

bool vt::collective::tree::Tree::isRoot() const

Get whether this node is the root.

Returns	whether this node is the root

NodeListType const & vt::collective::tree::Tree::getChildren() const

Get the (const) list of children.

Returns	(const) list of children

NodeListType vt::collective::tree::Tree::getChildren(NodeType node) const

Get the list of children for a particular node in the tree.

Returns	list of children

void vt::collective::tree::Tree::foreachChild(OperationType op) const

Apply function (foreach) across all children.

Parameters
op in	action to apply, passed the node

NumLevelsType vt::collective::tree::Tree::numLevels() const

Get number of levels in the tree.

Returns	number of levels

void vt::collective::tree::Tree::foreachChild(NumLevelsType level, OperationType op) const

Apply function (foreach) across all children with number of levels passed to apply function.

Parameters
level in	number of levels in spanning tree
op in	action to apply, passed levels and node

std::size_t vt::collective::tree::Tree::getNumDescendants(NodeType child) const

Get total number of descendants for a particular node in the tree.

Parameters
child in	the node
Returns	number of descendants

\internalThe returned count does not include the node passed—only its descendants.

std::size_t vt::collective::tree::Tree::getNumDescendants() const

Get total number of descendants in the tree.

Returns	number of descendants