# NAG CL Interfacex06afc (in_​parallel)

## 1Purpose

x06afc returns $1$ if called from within an active OpenMP parallel region, and $0$ otherwise.

## 2Specification

 #include
 Integer x06afc ()
The function may be called by the names: x06afc or nag_omp_in_parallel.

## 3Description

x06afc, for multithreaded implementations, returns $1$ if called from within an active OpenMP parallel region, and $0$ otherwise.
In serial implementations of the NAG Library this function will always return $0$. See the X06 Chapter Introduction for a discussion of the behaviour of these functions when called in serial.

## 4References

The OpenMP API Specification for Parallel Programming
Chapman B, Jost G and van der Pas R (2008) Using OpenMP Portable Shared Memory Parallel Programming The MIT Press

None.

None.

Not applicable.

## 8Parallelism and Performance

x06afc is not threaded in any implementation.