Virtual Memory Routines Use Far Heap

Last reviewed: July 22, 1997
Article 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

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Last reviewed: July 22, 1997
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