Properties of Device Objects

Each device object has certain properties that describe the device and how the device object interacts with the system. The device object properties include:

• Device type. Specifies the device's type of hardware. For more information about device types, see Specifying Device Types.
• Device characteristics. Specifies flags that provide additional information about the device. For more information, see Specifying Device Characteristics.
• Exclusive access. Specifies whether the device object represents an exclusive device. If the device is exclusive, only one handle can be open for the device object at a time. (If the underlying device supports overlapped I/O, multiple threads of the same process can send requests through a single handle.) For more information, see Specifying Exclusive Access to Device Objects.
• Security descriptor. Device objects have a security descriptor that controls access to the device. For more information, see Securing Device Objects.

For each of these properties, a default value can be set when the device object is created. For more information on creating device objects, see Creating a Device Object.

Values for device object properties can also be set in the registry. See Setting Device Object Properties in the Registry for more information.