_heapchk

Artiklu
08/03/2021
2 minuti biex taqra

Runs consistency checks on the heap.

Syntax

int _heapchk( void );

Return Value

_heapchk returns one of the following integer manifest constants defined in Malloc.h.

Return value	Condition
_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.

By default, this function's global state is scoped to the application. To change this, see Global state in the CRT.

Requirements

Routine	Required header	Optional header
_heapchk	<malloc.h>	<errno.h>

For more compatibility information, see Compatibility.

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