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NF:memoryapi.OfferVirtualMemory

OfferVirtualMemory function (memoryapi.h)

Indicates that the data contained in a range of memory pages is no longer needed by the application and can be discarded by the system if necessary.

OfferVirtualMemory

OfferVirtualMemory function

VMOfferPriorityBelowNormal

VMOfferPriorityLow

VMOfferPriorityNormal

VMOfferPriorityVeryLow

base.offervirtualmemory

winbase/OfferVirtualMemory

base\offervirtualmemory.htm

base

45f8a433-0a9e-31d1-f21d-a17d7247e164

12/05/2018

OfferVirtualMemory, OfferVirtualMemory function, VMOfferPriorityBelowNormal, VMOfferPriorityLow, VMOfferPriorityNormal, VMOfferPriorityVeryLow, base.offervirtualmemory, winbase/OfferVirtualMemory

memoryapi.h

Windows.h, Memoryapi.h

Windows

Windows 8.1 Update [desktop apps \| UWP apps]

Windows Server 2012 R2 Update [desktop apps \| UWP apps]

onecore.lib

Kernel32.dll

Windows

19H1

OfferVirtualMemory

memoryapi/OfferVirtualMemory

c++

APIRef

kbSyntax

DllExport

Kernel32.dll

API-MS-Win-Core-memory-l1-1-2.dll

KernelBase.dll

API-MS-Win-Core-memory-l1-1-3.dll

MinKernelBase.dll

API-MS-Win-Core-Memory-L1-1-4.dll

OfferVirtualMemory

OfferVirtualMemory function

-description

Indicates that the data contained in a range of memory pages is no longer needed by the application and can be discarded by the system if necessary.

The specified pages will be marked as inaccessible, removed from the process working set, and will not be written to the paging file.

To later reclaim offered pages, call ReclaimVirtualMemory.

-parameters

-param VirtualAddress [in]

Page-aligned starting address of the memory to offer.

-param Size [in]

Size, in bytes, of the memory region to offer. Size must be an integer multiple of the system page size.

-param Priority [in]

Priority indicates how important the offered memory is to the application. A higher priority increases the probability that the offered memory can be reclaimed intact when calling ReclaimVirtualMemory. The system typically discards lower priority memory before discarding higher priority memory. Priority must be one of the following values.

Value	Meaning
VMOfferPriorityVeryLow 0x00000001	The offered memory is very low priority, and should be the first discarded.
VMOfferPriorityLow 0x00000002	The offered memory is low priority.
VMOfferPriorityBelowNormal 0x00000003	The offered memory is below normal priority.
VMOfferPriorityNormal 0x00000004	The offered memory is of normal priority to the application, and should be the last discarded.

-returns

ERROR_SUCCESS if successful; a System Error Code otherwise.

-remarks

To reclaim offered pages, call ReclaimVirtualMemory. The data in reclaimed pages may have been discarded, in which case the contents of the memory region is undefined and must be rewritten by the application.

Do not call OfferVirtualMemory to offer virtual memory that is locked. Doing so will unlock the specified range of pages.

Note that offering and reclaiming virtual memory is similar to using the MEM_RESET and MEM_RESET_UNDO memory allocation flags, except that OfferVirtualMemory removes the memory from the process working set and restricts access to the offered pages until they are reclaimed.