auto_partitioner Class


Specify that a parallel loop should optimize its range subdivision based on work-stealing events.


#include "tbb/partitioner.h"


class auto_partitioner;


A loop template with an auto_partitioner attempts to minimize range splitting while providing ample opportunities for work-stealing.

The range subdivision is initially limited to S subranges, where S is proportional to the number of threads specified by the task_scheduler_init or task_arena. Each of these subranges is not divided further unless it is stolen by an idle thread. If stolen, it is further subdivided to create additional subranges. Thus a loop template with an auto_partitioner creates additional subranges only when necessary to balance load.


When using auto_partitioner and a blocked_range for a parallel loop, the body may receive a subrange larger than the grain size of the blocked_range. Therefore do not assume that the grain size is an upper bound on the size of a subrange. Use simple_partitioner if an upper bound is required.


namespace tbb {
    class auto_partitioner {
The following table provides additional information on the members of this template class.
Member Description

Construct an auto_partitioner.


Destroy this auto_partitioner.

For more complete information about compiler optimizations, see our Optimization Notice.