DosQueryMemState

Prototype

APIRET APIENTRY DosQueryMemState ( PVOID addr, PULONG psize, PULONG pflags ) ; 

Linkage Definition:

IMPORTS DOSQUERYMEMSTATE = DOSCALL1.307 

Parameters

PVOID addr

Base address of pages to be queried.

PULONG psize

Pointer to location in user space that contains the requested size of the region to query.

PULONG pflags

Pointer to location in user space that will receive the attribute flags describing the region.

Comments

This function returns zero if successful. The attribute flags are defined as follows:

┌────────────────────┬──────────┬──────────────────────────────────┐
│PAG_NPOUT           │0x00000000│Page is not present, not in core. │
├────────────────────┼──────────┼──────────────────────────────────┤
│PAG_PRESENT         │0x00000001│Page is present.                  │
├────────────────────┼──────────┼──────────────────────────────────┤
│PAG_NPIN            │0x00000002│Page is not present, but in core. │
├────────────────────┼──────────┼──────────────────────────────────┤
│PAG_PRESMASK        │0x00000003│Present state mask.               │
├────────────────────┼──────────┼──────────────────────────────────┤
│PAG_RESIDENT        │0x00000010│Page is resident (non-swappable). │
├────────────────────┼──────────┼──────────────────────────────────┤
│PAG_SWAPPABLE       │0x00000020│Page is swappable.                │
├────────────────────┼──────────┼──────────────────────────────────┤
│PAG_DISCARDABLE     │0x00000030│Page is discardable.              │
└────────────────────┴──────────┴──────────────────────────────────┘

The information returned by this function is extremely volatile, and decisions based upon it should reflect that volatility.