heapchk.txt

[随书类]Dos6.0源代码

SUMMARY heapchk heapset heapinfo

#include <tools.h>

long lHeapSize;
long lHeapFree;
long lHeapLargest;

int heapchk ( );

int heapset ( fillchar )
int fillchar;

int heapinfo ( );

long heapsize ( );

long heapfree ( );

DESCRIPTION

heapchk checks the heap for consistency.

heapset sets free nodes in the heap to the fillchar.

heapinfo set the values of lHeapSize, lHeapFree, lHeapLargest. lHeapSize is
the size of the heap in bytes (including headers), lHeapFree is free space
(including headers), lHeapLargest is size in bytes of the largest free node
(doesn't include 2 bytes needed for the header).

heapsize calls heapinfo and if HEAPOK returns lHeapSize else returns
error code.

heapfree, same as heapsize, except returns number of free bytes (including
headers) in heap.


RETURN VALUE

heapchk, heapset and heapinfo return HEALPOK if operation successful.

All return HEAPCANTFIND or HEAPBADNODE if there are problems with the heap.
Since heapsize and heapfree return longs, you must do appropriate casting.

    HEAPOK          - completed okay, or not initialized yet
    HEAPCANTFIND    - can't find heap, initial node trashed
    HEAPBADNODE     - malformed node somewhere in heap


IMPLEMENTATION



EXAMPLE

#include <tools.h>

extern long lHeapSize;
extern long lHeapFree;

main(c, argv)
int c;
char *argv[];
{
    flagType fHeapChk;

    if ( ( fHeapChk = heapchk ( ) ) != HEAPOK )
        fprintf ( stderr, "%s\n", ( fHeapChk == HEAPCANTFIND ?
            "Can't find heap" : "Damaged heap" ) );

    if ( ( fHeapChk = heapset ( '?') ) != HEAPOK )
        fprintf ( stderr, "%s\n", ( fHeapChk == HEAPCANTFIND ?
            "Can't find heap" : "Damaged heap" ) );

    if ( heapinfo ( ) == HEAPOK )
        fprintf ( stderr, "Heap size:%5ld  used:%5ld\n", lHeapSize,
            lHeapSize - lHeapFree );
}