Runs consistency checks on the heap.
int _heapchk( void );
| Routine | Required Header | Optional Headers | Compatibility |
| _heapchk | <malloc.h> | <errno.h> | Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| LIBC.LIB | Single thread static library, retail version |
| LIBCMT.LIB | Multithread static library, retail version |
| MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
Return Value
_heapchk returns one of the following integer manifest constants defined in MALLOC.H:
_HEAPBADBEGIN
Initial header information is bad or cannot be found
_HEAPBADNODE
Bad node has been found or heap is damaged
_HEAPBADPTR
Pointer into heap is not valid
_HEAPEMPTY
Heap has not been initialized
_HEAPOK
Heap appears to be consistent
In addition, if an error occurs, _heapchk sets errno to ENOSYS.
Remarks
The _heapchk function helps debug heap-related problems by checking for minimal consistency of the heap.
Example
/* HEAPCHK.C: This program checks the heap for
* consistency and prints an appropriate message.
*/
#include <malloc.h>
#include <stdio.h>
void main( void )
{
int heapstatus;
char *buffer;
/* Allocate and deallocate some memory */
if( (buffer = (char *)malloc( 100 )) != NULL )
free( buffer );
/* Check heap status */
heapstatus = _heapchk();
switch( heapstatus )
{
case _HEAPOK:
printf(" OK - heap is fine\n" );
break;
case _HEAPEMPTY:
printf(" OK - heap is empty\n" );
break;
case _HEAPBADBEGIN:
printf( "ERROR - bad start of heap\n" );
break;
case _HEAPBADNODE:
printf( "ERROR - bad node in heap\n" );
break;
}
}
Output
OK - heap is fine