USB_BUS_STATISTICS_0 structure (usbuser.h)

The USB_BUS_STATISTICS_0 structure is used with the IOCTL_USB_USER_REQUEST I/O control request to retrieve bus statistics.

Syntax

typedef struct _USB_BUS_STATISTICS_0 {
  ULONG         DeviceCount;
  LARGE_INTEGER CurrentSystemTime;
  ULONG         CurrentUsbFrame;
  ULONG         BulkBytes;
  ULONG         IsoBytes;
  ULONG         InterruptBytes;
  ULONG         ControlDataBytes;
  ULONG         PciInterruptCount;
  ULONG         HardResetCount;
  ULONG         WorkerSignalCount;
  ULONG         CommonBufferBytes;
  ULONG         WorkerIdleTimeMs;
  BOOLEAN       RootHubEnabled;
  UCHAR         RootHubDevicePowerState;
  UCHAR         Unused;
  UCHAR         NameIndex;
} USB_BUS_STATISTICS_0, *PUSB_BUS_STATISTICS_0;

Members

DeviceCount

The number of devices on the bus.

CurrentSystemTime

The current system time.

CurrentUsbFrame

The number of the current USB frame.

BulkBytes

The amount, in bytes, of bulk transfer data.

IsoBytes

The amount, in bytes, of isochronous data.

InterruptBytes

The amount, in bytes, of interrupt data.

ControlDataBytes

The amount, in bytes, of control data.

PciInterruptCount

The amount, in bytes, of interrupt data.

HardResetCount

The number of hard bus resets that have occurred.

WorkerSignalCount

The number of times that a worker thread has signaled completion of a task.

CommonBufferBytes

The number of bytes that are transferred by common buffer.

WorkerIdleTimeMs

The amount of time, in milliseconds, that worker threads have been idle.

RootHubEnabled

A Boolean value that indicates whether the root hub is enabled. If TRUE, he root hub is enabled. If FALSE, the root hub is disabled.

RootHubDevicePowerState

The power state of the root hub devices. This member can have any of the following values:

Unused

If this member is 1, the bus is active. If 0, the bus is inactive.

NameIndex

The index that is used to generate a symbolic link name for the hub PDO. This format of the symbolic link is USBPDO-n, where n is the value in NameIndex.

Remarks

The USB_BUS_STATISTICS_0 structure is used with the USBUSER_BUS_STATISTICS_0 user-mode request. For a description of this request, see IOCTL_USB_USER_REQUEST.

In Windows 8, this request completes successfully. However, the values retrieved from the underlying USB 3.0 driver stack do not reflect actual bus statistics.

Requirements

See also

IOCTL_USB_USER_REQUEST

USB Structures