1.. _attach_flow_graph_to_arena:
2
3Attach Flow Graph to an Arbitrary Task Arena
4=============================================
5
6
7|short_name| ``task_arena`` interface provides mechanisms to guide tasks
8execution within the arena by setting the preferred computation units,
9restricting part of computation units, or limiting arena concurrency. In some
10cases, you may want to apply such mechanisms when a flow graph executes.
11
12During its construction, a ``graph`` object attaches to the arena, in which the constructing
13thread occupies a slot.
14
15This example shows how to set the most performant core type as the preferred one
16for a graph execution:
17
18
19.. literalinclude:: ./snippets/flow_graph_examples.cpp
20   :language: c++
21   :start-after: /*begin_attach_to_arena_1*/
22   :end-before: /*end_attach_to_arena_1*/
23
24
25A ``graph`` object can be reattached to a different ``task_arena`` by calling
26the ``graph::reset()`` function. It reinitializes and reattaches the ``graph`` to
27the task arena instance, inside which the ``graph::reset()`` method is executed.
28
29This example shows how to reattach existing graph to an arena with the most performant
30core type as the preferred one for a work execution. Whenever a task is spawned on behalf
31of the graph, it is spawned in the arena of a graph it is attached to, disregarding
32the arena of the thread that the task is spawned from:
33
34
35.. literalinclude:: ./snippets/flow_graph_examples.cpp
36   :language: c++
37   :start-after: /*begin_attach_to_arena_2*/
38   :end-before: /*end_attach_to_arena_2*/
39
40See the following topics to learn more:
41
42.. toctree::
43   :maxdepth: 4
44
45   ../tbb_userguide/Guiding_Task_Scheduler_Execution
46   ../tbb_userguide/work_isolation
47
48