Virtual Memory Routines Use Far Heap

ID: Q117781

7.00 | 1.00 1.50 MS-DOS | WINDOWS kbprg

The information in this article applies to:

• The C Run-time (CRT), included with:

      - Microsoft C/C++ for MS-DOS, version 7.0
      - Microsoft Visual C++ for Windows, versions 1.0 and 1.5
  

The virtual memory functions in the Microsoft C Run Time libraries always use a far heap for managing internal information. The far heap is used for keeping a log of free memory blocks and consists of a series of 12-byte blocks.

If you are analyzing heap use with _heapwalk() in a small- or medium- memory model application, this information is hidden. However, _fheapwalk() correctly reports use of the far heap.

Using _vheapterm() to terminate the virtual memory manager frees any memory allocated for the virtual memory manager; therefore, the far heap is freed for applications that have a single data segment.

Additional reference words: kbinf 7.00 1.00 1.50 _vmalloc _vfree KBCategory: kbprg KBSubcategory: CRTIss Keywords : kb16bitonly

Last Reviewed: July 23, 1997