# NAG Library Routine Document

## g22zaf (handle_free)

Note: please be advised that this routine is classed as ‘experimental’ and its interface may be developed further in the future. Please see Section 3.1.1 in How to Use the NAG Library and its Documentation for further information.

## 1Purpose

g22zaf destroys a G22 handle and deallocates all the memory used.

## 2Specification

Fortran Interface
 Subroutine g22zaf (
 Integer, Intent (Inout) :: ifail Type (c_ptr), Intent (Inout) :: handle
#include <nagmk26.h>
 void g22zaf_ (void **handle, Integer *ifail)

## 3Description

Each G22 handle should be deallocated to avoid memory leaks. Therefore, g22zaf should be called on all such handles which are no longer needed. Please note that passing an uninitialized handle might cause unpredictable behaviour, including a crash of your program.

None.

## 5Arguments

1:     $\mathbf{handle}$ – Type (c_ptr)Input/Output
On entry: the G22 handle to be destroyed.
On exit: the handle is destroyed and set to c_null_ptr.
2:     $\mathbf{ifail}$ – IntegerInput/Output
On entry: ifail must be set to $0$, . If you are unfamiliar with this argument you should refer to Section 3.4 in How to Use the NAG Library and its Documentation for details.
For environments where it might be inappropriate to halt program execution when an error is detected, the value  is recommended. If the output of error messages is undesirable, then the value $1$ is recommended. Otherwise, if you are not familiar with this argument, the recommended value is $0$. When the value  is used it is essential to test the value of ifail on exit.
On exit: ${\mathbf{ifail}}={\mathbf{0}}$ unless the routine detects an error or a warning has been flagged (see Section 6).

## 6Error Indicators and Warnings

If on entry ${\mathbf{ifail}}=0$ or $-1$, explanatory error messages are output on the current error message unit (as defined by x04aaf).
Errors or warnings detected by the routine:
${\mathbf{ifail}}=11$
handle has not been initialized.
${\mathbf{ifail}}=12$
handle has been corrupted.
${\mathbf{ifail}}=13$
handle is a handle to an unknown data structure.
${\mathbf{ifail}}=-99$
See Section 3.9 in How to Use the NAG Library and its Documentation for further information.
${\mathbf{ifail}}=-399$
Your licence key may have expired or may not have been installed correctly.
See Section 3.8 in How to Use the NAG Library and its Documentation for further information.
${\mathbf{ifail}}=-999$
Dynamic memory allocation failed.
See Section 3.7 in How to Use the NAG Library and its Documentation for further information.

Not applicable.

## 8Parallelism and Performance

g22zaf is not threaded in any implementation.