_heapchk

Runs consistency checks on the heap.

int _heapchk( void );

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. If the operating system does not support _heapchk(for example, Windows 98), the function returns _HEAPOK and sets errno to ENOSYS.

Requirements

For more compatibility information, see Compatibility in the Introduction.

Example

// crt_heapchk.c
// This program checks the heap for
// consistency and prints an appropriate message.
 
#include <malloc.h>
#include <stdio.h>

int 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;
   }
}

 OK - heap is fine

.NET Framework Equivalent

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

See Also

Reference

Memory Allocation

_heapadd

_heapmin

_heapset

_heapwalk