SwDeviceClose function (swdevice.h)

Closes the software device handle. When the handle is closed, if the lifetime of the SwDevice is SWDeviceLifetimeHandle, PnP will initiate the process of "unplugging" the device. The device will no longer be reported as a child of its parent device.

Syntax

void SwDeviceClose(
  [in] HSWDEVICE hSwDevice
);

Parameters

[in] hSwDevice

The HSWDEVICE handle to close.

Return value

None

Remarks

After SwDeviceClose returns, the operating system is guaranteed to not call the SW_DEVICE_CREATE_CALLBACK callback function, and any calls to Software Device API functions that were in progress are guaranteed to have completed.

You can call SwDeviceClose at any time even if the callback function hasn't been called yet.

In Windows 8, you can't call SwDeviceClose inside the SW_DEVICE_CREATE_CALLBACK callback function. Doing so will cause a deadlock. Be careful of releasing a ref counted object that will call SwDeviceClose when its destructor runs. In Windows 8.1, this restriction is lifted, and you can call SwDeviceClose inside the callback function.

By calling SwDeviceClose, if the lifetime of the SwDevice is SWDeviceLifetimeHandle, you initiate the process of "unplugging" the device. This causes the device to no longer be reported as a child of its parent which causes PnP to issue a "surprise removal" of the device. The call to SwDeviceClose returns before this removal is complete. However, you can safely call SwDeviceCreate immediately after SwDeviceClose. The new create will be queued until the previous removal processing completes, and then the device will be re-created.

PnP removal makes the device "Not present" and does not uninstall the device. PnP removal of a device is the same as unplugging a USB device and all of the persisted property state for the device will remain. If you wish to uninstall the device after calling SwDeviceClose, see Uninstalling the device.

Requirements

See also

SwDeviceCreate