CopyCapabilityDescriptors
Returns the device’s capability descriptors.
Declaration
virtual const IOUSBBOSDescriptor * CopyCapabilityDescriptors();Return Value
A pointer to the binary object store (BOS) descriptor, or NULL if the descriptor wasn’t found. It’s your responsibility to free the returned descriptor.
Discussion
This method searches the descriptor cache for the specified descriptors. If they aren’t in the cache, the method retrieves the descriptors from the device using a GET_DESCRIPTOR control request (USB 2.0, section 9.4.3) and adds them to the cache. When making a GET_DESCRIPTOR control request, this method acquires the service’s workloop lock and may call commandSleep.