Waitforevent() - Intel Extensible Firmware Interface Specification

3.1.4

WaitForEvent()

Summary
Stops execution until an event is signaled.
Prototype
EFI_STATUS
WaitForEvent (
IN UINTN
IN EFI_EVENT
OUT UINTN
);
Parameters
NumberOfEvents
Event
Index
Description
The WaitForEvent()function waits for any event in the
success, the signaled state of the event is cleared and execution is returned with
which event caused the return. It is possible for an event to be signaled before being waited on. In
this case, the next wait operation for that event would immediately return with the signaled event.
Waiting on an event of type
type EVT_NOTIFY_SIGNAL, WaitForEvent()returns
sets to indicate which event caused the failure. This function must be called at priority
Index
level TPL_APPLICATION. If an attempt is made to call it at any other priority level,
EFI_UNSUPPORTED
To wait for a specified time, a timer event must be included in the
WaitForEvent()
being checked first. To check if an event is signaled without waiting, an already signaled event can
be used as the last event in the list being checked, or the
Status Codes Returned
EFI_SUCCESS
EFI_INVALID_PARAMETER
EFI_UNSUPPORTED
Version 1.02
The number of events in the
An array of EFI_EVENT. Type
Section 3.1.1.
Pointer to the index of the event which satisfied the wait condition.
EVT_NOTIFY_SIGNAL
is returned.
will always check for signaled events in order, with the first event in the array
The event indicated by
The event indicated by
Event
was not a valid type.
The current TPL is not
NumberOfEvents,
*Event,
*Index
array.
Event
is defined in
EFI_EVENT
array to be signaled. On
Event
is not permitted. If any event in
EFI_INVALID_PARAMETER
array.
Event
CheckEvent()
Index
was signaled.
Index
has a notification function or
TPL_APPLICATION
12/12/00
Services
indicating
Index
is of
Event
and
interface may be used.
.
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