heapcheckfree

raw OCR

Checks the free blocks on the heap for a constant value.

Defined in header <alloc.h>

Syntax

#include <alloc.h>
int heapcheckfree(unsigned  int fillvalue);

Portability

DOS	UNIX	Windows	ANSI C	C++ only
■

Return value

The return value is less then zero for an error and greater than zero for success. The return values and their meaning is as follows:

_HEAPEMPTY	no heap (value 1).
_HEAPOK	heap is accurate (value 2).
_HEAPCORRUPT	heap has been corrupted (value -1).
_BADVALUE	a value other than the fill value was found (value -3).

Example

#include <stdio.h>
#include <alloc.h>
#include <mem.h>
#define NUM_PTRS  10
Mefine  NUM_BYTES 16
int main(void)
{
   char *arraY[ NUM_PTRS
   int i, res;

   for( i = 0; i < NUM_PTRS;  i++ )
      array [ i ] = (char *) malloc( NUM_BYTES
   for( i * 0; i < NUM_PTRS;  i += 2 )
      free( array [ i ] );
   if( heapfillfreel 1  ) < 0 ) {
      printf( "Heap corrupted. \n" );
      return 1;
   }
   for( i = 1; i < NUM_PTRS;  i += 2 )
      memset( array [ i ], 0, NUM_BYTES );
   res = heapcheckfree ( 1 );
   if( res < 0 )
      switch( res ) {
         case _HEAPCORRUPT:
              printf( "Heap corrupted. \n" );
              return 1;
         case _BADVALUE:
              printf (     value  in free space.\n"
              return 1;  ■
         default:
              printf ( "Unknown error.\n"
              return 1;

   printf( "Test successful.\n"
   return 0;

Differences from modern implementations

Nothing recorded yet.

Modern references

Microsoft C runtime (search)

These are search links, not yet checked by hand.

Stable link: /3.1/alloc.h/heapcheckfree/ · short form /3.1/heapcheckfree/