X06 Chapter Contents
X06 Chapter Introduction
NAG Library Manual

# NAG Library Routine DocumentX06AHF

Note:  before using this routine, please read the Users' Note for your implementation to check the interpretation of bold italicised terms and other implementation-dependent details.

## 1  Purpose

X06AHF returns $1$ if nested OpenMP parallelism has been enabled, and $0$ otherwise.

## 2  Specification

 FUNCTION X06AHF ( )
 INTEGER X06AHF

## 3  Description

X06AHF, for multi-threaded implementations, tests whether the nesting of OpenMP parallel regions has been enabled as if with a call to X06AGF. The return value will be $1$ if nesting is enabled or $0$ if it is disabled.
Note the equivalent OpenMP routine omp_get_nested() returns a logical value.
In serial implementations of the NAG Library X06AHF will always return $0$. See the X06 Chapter Introduction for a discussion of the behaviour of these routines when called in serial.

## 4  References

OpenMP Specifications http://openmp.org/wp/OpenMP-Specifications
Chapman B, Jost G and van der Pas R (2008) Using OpenMP Portable Shared Memory Parallel Programming The MIT Press

None.

None.

Not applicable.

## 8  Parallelism and Performance

X06AHF is not threaded in any implementation.