Purpose

DosQueryMemState gets the status of a range of pages in memory. Its input parameters are an address and size. The address is rounded down to page boundary and size is rounded up to a whole number of pages. The status of the pages in the range is returned in the state parameter, and the size of the range queried is returned in the size parameter. If the pages in the range have conflicting states, then the state of the first page is returned.

Syntax

#define INCL_PROFILE
#include  os2.h>

APIRET APIENTRY DosQueryMemState

(PVOID pMem, PULONG size, PULONG state)

Parameters

pMem (PVOID) input

size (PULONG) input/output
state (PLONG) output
Flags indicate the following page states

PAG_NPOUT 0x00000000

Page is not present, not in core.
PAG_PRESENT 0x00000001
Page is present.
PAG_NPIN 0x00000002
Page is not present, in core.
PAG_PRESMASK 0x00000003
Present state mask.
PAG_INVALID 0x00000000
Page is invalid.
PAG_RESIDENT 0x00000010
Page is resident.
PAG_SWAPPABLE 0x00000020
Page is swappable.
PAG_DISCARDABLE 0x00000030
Page is discardable.
PAG_TYPEMASK 0x00000030
Typemask.

Returns

ulrc (APIRET) returns

Return Code.

DosQueryMemState returns one of the following values

• NO_ERROR

  87

  ERROR_INVALID_PARAMETER
  487
  ERROR_INVALID_ADDRESS

  Related Functions

  • DosQueryMem

  Example Code

  int main(int argc, char *argv[], char *envp[]){
     APIRET rc=0;
     PVOID pMem;
     ULONG status;
     ULONG size;
     ULONG pages;
     ULONG onepage = 0x1000;
  
     if (argc   3) {
  
        printf("Syntax  MEMSTATE  address>  size>\n");
        return 0;
  
     } else {
  
        pMem = (PVOID) strtoul(argv[1], NULL, 0);
        size = strtoul(argv[2], NULL, 0);
        pages = (size+0x0fff) >> 12;
  
        printf("address     state\n");
        while (pages--) {
  
           rc = DosQueryMemState(pMem,  onepage,  status);
  
           if (rc) printf("0x%08x DosQueryMemState returned %u\n",pMem, rc);
           else {
              printf("0x%08x 0x%08x ", pMem, status);
              if ((status   PAG_PRESMASK) == PAG_NPOUT) printf("not present, not in-core, ");
              else if (status   PAG_PRESENT) printf("present, in-core, ");
              else if (status   PAG_NPIN) printf("not present, in-core, ");
  
              if ((status   PAG_TYPEMASK) == PAG_INVALID) printf("invalid\n");
              if ((status   PAG_TYPEMASK) == PAG_RESIDENT) printf("resident\n");
              if ((status   PAG_TYPEMASK) == PAG_SWAPPABLE) printf("swappable\n");
              if ((status   PAG_TYPEMASK) == PAG_DISCARDABLE) printf("discardable\n");
           }
           pMem = (PVOID)((ULONG)pMem + 0x1000);
  
        } /* endwhile */
  
     } /* end if*/
  
     return rc;
  }
  
  

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