Intel Extensible Firmware Interface - Manual (Page 110)

Extensible Firmware Interface Specification
5-12 12/01/02 Version 1.10
CheckEvent()
Summary
Checks whether an event is in the signaled state.
Prototype
EFI_STATUS
CheckEvent (
IN EFI_EVENT Event
);
Parameters
Event The event to check. Type EFI_EVENT is defined in the
CreateEvent() function description.
Description
The CheckEvent() function checks to see whether Event is in the signaled state. If Event is
of type EVT_NOTIFY_SIGNAL , then EFI_INVALID_PARAMETER is returned. Otherwise,
there are three possibilities:
• If
Event is in the signaled state, it is cleared and EFI_SUCCESS is returned.
• If
Event is not in the signaled state and has no notification function, EFI_NOT_READY is
returned.
• If
Event is not in the signaled state but does have a notification function, the function is
executed. If that causes Event to be signaled, it is cleared and EFI_SUCCESS is returned; if
it does not cause Event to be signaled, EFI_NOT_READY is returned.
Status Codes Returned
EFI_SUCCESS The event is in the signaled state.
EFI_NOT_READY The event is not in the signaled state.
EFI_INVALID_PARAMETER Event is of type EVT_NOTIFY_SIGNAL .