PHYSICAL_COUNTER_RESOURCE_DESCRIPTOR structure (ntddk.h)
The PHYSICAL_COUNTER_RESOURCE_DESCRIPTOR structure describes the counter resources available on the platform.
Syntax
typedef struct _PHYSICAL_COUNTER_RESOURCE_DESCRIPTOR {
PHYSICAL_COUNTER_RESOURCE_DESCRIPTOR_TYPE Type;
ULONG Flags;
union {
ULONG CounterIndex;
struct {
ULONG Begin;
ULONG End;
} Range;
PPHYSICAL_COUNTER_OVERFLOW_HANDLER OverflowHandler;
PHYSICAL_COUNTER_EVENT_BUFFER_CONFIGURATION EventBufferConfiguration;
ULONG IdentificationTag;
} u;
} PHYSICAL_COUNTER_RESOURCE_DESCRIPTOR, *PPHYSICAL_COUNTER_RESOURCE_DESCRIPTOR;
Members
Type
Indicates the type of counter resource described by the structure. Set this parameter to one of the following PHYSICAL_COUNTER_RESOURCE_DESCRIPTOR_TYPE enumeration constants:
- ResourceTypeSingle
- ResourceTypeRange
- ResourceTypeOverflow
- ResourceTypeEventBuffer
Flags
No flags are currently defined. Set this member to zero.
u
A union that can contain a CounterIndex, Range, OverflowHandler, or EventBufferConfiguration value.
u.CounterIndex
A physical counter index.
u.Range
A range of counter indexes.
u.Range.Begin
The starting counter index of a block of contiguous counters.
u.Range.End
The ending counter index of a block of contiguous counters.
u.OverflowHandler
A pointer to the driver-supplied PPHYSICAL_COUNTER_OVERFLOW_HANDLER routine that will be called when an associated hardware counter (specified by another PHYSICAL_COUNTER_RESOURCE_DESCRIPTOR) overflows.
u.EventBufferConfiguration
A configuration for event buffer based sampling (such as Intel's PEBS). The configuration fields are defined by the PHYSICAL_COUNTER_EVENT_BUFFER_CONFIGURATION type.
u.IdentificationTag
Remarks
Most processors have performance monitor units that contain a number of hardware counters for measuring various aspects of system performance. The PHYSICAL_COUNTER_RESOURCE_DESCRIPTOR structure describes a counter resource, which can be a single hardware counter, a block of contiguous counters, a counter overflow interrupt, or an event buffer configuration. This structure's Type member indicates which type of counter resource is described by the structure.
To specify a set of counter resources, a kernel-mode client can provide an array of PHYSICAL_COUNTER_RESOURCE_DESCRIPTOR structures. A PHYSICAL_COUNTER_RESOURCE_LIST structure serves as a header for the array. The client can allocate and free the set of counter resources described by the array as a single unit. To do so, the driver calls HalAllocateHardwareCounters and HalFreeHardwareCounters
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Supported in Windows 7 and later versions of Windows. |
| Header | ntddk.h (include Ntddk.h, Ntifs.h) |