IOPMSystemCapabilityChangeParameters

A structure describing a system capability change.

Declaration

struct IOPMSystemCapabilityChangeParameters {
    ...
};

Discussion

A system capability change is a system level transition from a set of system capabilities to a new set of system capabilities. Power management sends a kIOMessageSystemCapabilityChange message and provides this structure as the message data (by reference) to gIOPriorityPowerStateInterest clients when system capability changes.

Topics

Fields

notifyRef

An identifier for this message notification. Clients with pending I/O can signal completion by calling allowPowerChange() with this value as the argument. Clients that are able to process the notification synchronously should ignore this field.

maxWaitForReply

A return value to the caller indicating the maximum time in microseconds to wait for the allowPowerChange() call. The default value is zero, which indicates the client processing has finished, and power management should not wait for an allowPowerChange() call.

changeFlags

Flags will be set to indicate whether the notification precedes the capability change (kIOPMSystemCapabilityWillChange), or after the capability change has occurred (kIOPMSystemCapabilityDidChange).

__reserved1

Set to zero.

fromCapabilities

The system capabilities at the start of the transition.

toCapabilities

The system capabilities at the end of the transition.

__reserved2

Set to zero.