• 2021.4
  • 09/27/2021
  • Public Content
Contents

follows and precedes function templates

To enable this feature, define the
TBB_PREVIEW_FLOW_GRAPH_FEATURES
macro to 1.
The
follows
and
precedes
helper functions aid in expressing dependencies between nodes when building oneTBB flow graphs. These helper functions can only be used while constructing the node.

Description

The
follows
helper function specifies that the node being constructed is the successor of the set of nodes passed as an argument.
The
precedes
helper function specifies that the node being constructed is the predecessor of the set of nodes passed as an argument.
Functions
follows
and
precedes
are meant to replace the graph argument, which is passed as the first argument to the constructor of the node. The graph argument for the node being constructed is obtained either from the specified node set or the sequence of nodes passed to
follows
or
precedes
.
If the nodes passed to
follows
or
precedes
belong to different graphs, the behavior is undefined.

API

Header
#include <oneapi/tbb/flow_graph.h>
Syntax
// node_set is an exposition-only name for the type returned from make_node_set function template <typename NodeType, typename... NodeTypes> /*unspecified*/ follows( node_set<NodeType, NodeTypes...>& set ); template <typename NodeType, typename... NodeTypes> /*unspecified*/ follows( NodeType& node, NodeTypes&... nodes ); template <typename NodeType, typename... NodeTypes> /*unspecified*/ precedes( node_set<NodeType, NodeTypes...>& set ); template <typename NodeType, typename... NodeTypes> /*unspecified*/ precedes( NodeType& node, NodeTypes&... nodes );
Input Parameters
Either a set or a sequence of nodes can be used as arguments for
follows
and
precedes
. The following expressions are equivalent:
auto handlers = make_node_set(n1, n2, n3); broadcast_node<int> input(precedes(handlers));
broadcast_node<int> input(precedes(n1, n2, n3));

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.