pcvmm.doc

公开的磁盘应用 C 语言工具包.zip

pcvmm.doc              Tuesday, March 1, 1990 1:00 pm                 Page 1

**********************************************************************
public functions - requires at least MSC 5.0+
**********************************************************************

unsigned int open_vmm(cha *swappath);
        This function inits. the VMM system. It will return ZERO
        on success otherwise a number indicating an error:

        VMM_ERR_NO_PAGE_MEM     1
            Not enough memory for page structures.


        VMM_ERR_NO_SWAP_FILE    2
            Could not create swap file

VHAND vmm_alloc(unsigned short size);
        Allocate size bytes in virtual memory heap. Returns a virtual
        handle (VHAND) that represents an allocated memory chunk. You
        must use vmm_deref() to bring the memory chunk into real
        memory.

VHAND vmm_realloc( VHAND vh, USHORT size );
        Re-allocate virtual memory chunk to passed size.

void far *vmm_deref( VHAND vmmaddr );
        Obtain a real memory address for passed virtual handle. The
        virtual memory page is only guaranteed to be in real memory
        until the next call to a vmm function.


USHORT vmm_size( VHAND vh)
        Returns the size in bytes of the allocated memory block. All
        allocations are rounded to an even number. So if the allocation
        request was three bytes it would be rounded to four bytes.

void vmm_dump(void)
        This procedure will dump all memory pages to external memory. This
        frees all DOS allocated memory. The next allocation or de-reference
        will start the DOS allocation process again.

void vmm_pack(void)
        This procedure will coalesce one "in memory" page for each call.
        This routine is intended to perform background packing of the heap.

void vmm_free( VHAND vh );
        Free virtual memory chunk.

void close_vmm(void);
        This function frees memory used by VMM system and removes
        the swap file.

*EOF*