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PERFORMANCE_DATA structure (winnt.h)

  • Article

Contains the thread profiling and hardware counter data that you requested.

Syntax

typedef struct _PERFORMANCE_DATA {
  WORD                  Size;
  BYTE                  Version;
  BYTE                  HwCountersCount;
  DWORD                 ContextSwitchCount;
  DWORD64               WaitReasonBitMap;
  DWORD64               CycleTime;
  DWORD                 RetryCount;
  DWORD                 Reserved;
  HARDWARE_COUNTER_DATA HwCounters[MAX_HW_COUNTERS];
} PERFORMANCE_DATA, *PPERFORMANCE_DATA;

Members

Size

The size of this structure.

Version

The version of this structure. Must be set to PERFORMANCE_DATA_VERSION.

HwCountersCount

The number of array elements in the HwCounters array that contain hardware counter data. A value of 3 means that the array contains data for three hardware counters, not that elements 0 through 2 contain counter data.

ContextSwitchCount

The number of context switches that occurred from the time profiling was enabled.

WaitReasonBitMap

A bitmask that identifies the reasons for the context switches that occurred since the last time the data was read. For possible values, see the KWAIT_REASON enumeration (the enumeration is included in the Wdm.h file in the WDK).

CycleTime

The cycle time of the thread (excludes the time spent interrupted) from the time profiling was enabled.

RetryCount

The number of times that the read operation read the data to ensure a consistent snapshot of the data.

Reserved

Reserved. Set to zero.

HwCounters[MAX_HW_COUNTERS]

An array of HARDWARE_COUNTER_DATA structures that contain the counter values. The elements of the array that contain counter data relate directly to the bits set in the HardwareCounters bitmask that you specified when you called the EnableThreadProfiling function. For example, if you set bit 3 in the HardwareCounters bitmask, HwCounters[3] will contain the counter data for that counter.

Remarks

You must initialize the Size and Version members before calling the ReadThreadProfilingData function to read the profiling data.

The profile data contained in this structure depends on the data that you requested when you called the ReadThreadProfilingData function. The following members are set when you specify the READ_THREAD_PROFILING_FLAG_DISPATCHING flag:

  • ContextSwitchCount
  • CycleTime
  • RetryCount
  • WaitReasonBitMap
The following members are set when you specify the READ_THREAD_PROFILING_FLAG_HARDWARE_COUNTERS flag:
  • HwCounters
  • HwCountersCount

Requirements

Requirement Value
Minimum supported client Windows 7 [desktop apps only]
Minimum supported server Windows Server 2008 R2 [desktop apps only]
Header winnt.h (include Windows.h)

See also

ReadThreadProfilingData