Returns the size of memory available.
| #include <malloc.h> | Required only for function declarations |
size_t _memavl( void );
The _memavl function returns the approximate size, in bytes, of the memory available for dynamic memory allocation in the near heap (default data segment). The _memavl function can be used with calloc, malloc, or realloc in tiny, small, and medium memory models and with _ncalloc, _nmalloc or _nrealloc in any memory model.
The number returned by the _memavl function may not be the number of contiguous bytes. Consequently, a call to malloc requesting allocation of the size returned by _memavl may not succeed. Use the _memmax function to find the size of the largest available contiguous block of memory.
The _memavl function returns the size in bytes as an unsigned integer.
Standards:None
16-Bit:DOS, QWIN, WIN, WIN DLL
32-Bit:None
calloc functions, _freect, malloc functions, _memmax, realloc functions
/* MEMAVL.C: This program uses _memavl to determine the amount of
* memory available for dynamic allocation. It then uses malloc to
* allocate space for 5,000 long integers and uses _memavl again to
* determine the new amount of available memory.
*/
#include <malloc.h>
#include <stdio.h>
void main( void )
{
long *longptr;
printf( "Memory available before _nmalloc = %u\n", _memavl() );
if( (longptr = _nmalloc( 5000 * sizeof( long ) )) != NULL )
{
printf( "Memory available after _nmalloc = %u\n", _memavl() );
_nfree( longptr );
}
}
Memory available before _nmalloc = 60906
Memory available after _nmalloc = 40390