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PSAPI_WORKING_SET_BLOCK union (psapi.h)

  • Article

Contains working set information for a page.

Syntax

typedef union _PSAPI_WORKING_SET_BLOCK {
  ULONG_PTR Flags;
  struct {
    ULONG_PTR Protection : 5;
    ULONG_PTR ShareCount : 3;
    ULONG_PTR Shared : 1;
    ULONG_PTR Reserved : 3;
#if ...
    ULONG_PTR VirtualPage : 52;
#else
    ULONG_PTR VirtualPage : 20;
#endif
  };
} PSAPI_WORKING_SET_BLOCK, *PPSAPI_WORKING_SET_BLOCK;

Members

Flags

The working set information. See the description of the structure members for information about the layout of this variable.

Protection

The protection attributes of the page. This member can be one of the following values.

Value Meaning
0
 The page is not accessed.
1
 Read-only.
2
 Executable.
3
 Executable and read-only.
4
 Read/write.
5
 Copy-on-write.
6
 Executable and read/write.
7
 Executable and copy-on-write.
8
 The page is not accessed.
9
 Non-cacheable and read-only.
10
 Non-cacheable and executable.
11
 Non-cacheable, executable, and read-only.
12
 Non-cacheable and read/write.
13
 Non-cacheable and copy-on-write.
14
 Non-cacheable, executable, and read/write.
15
 Non-cacheable, executable, and copy-on-write.
16
 The page is not accessed.
17
 Guard page and read-only.
18
 Guard page and executable.
19
 Guard page, executable, and read-only.
20
 Guard page and read/write.
21
 Guard page and copy-on-write.
22
 Guard page, executable, and read/write.
23
 Guard page, executable, and copy-on-write.
24
 The page is not accessed.
25
 Non-cacheable, guard page, and read-only.
26
 Non-cacheable, guard page, and executable.
27
 Non-cacheable, guard page, executable, and read-only.
28
 Non-cacheable, guard page, and read/write.
29
 Non-cacheable, guard page, and copy-on-write.
30
 Non-cacheable, guard page, executable, and read/write.
31
 Non-cacheable, guard page, executable, and copy-on-write.

ShareCount

The number of processes that share this page. The maximum value of this member is 7.

Shared

If this bit is 1, the page is sharable; otherwise, the page is not sharable.

Reserved

This member is reserved.

VirtualPage

The address of the page in the virtual address space.

64-bit Windows:  This member is 52 bits in length.

Requirements

Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Header psapi.h

See also

PSAPI_WORKING_SET_INFORMATION