Creating Event in an EventGroup that has already been signaled

Creating Event in an EventGroup that has already been signaled

[Tomas Pilar (tpilar)]

What would be the state of that event post creation. Would it be 
immediately signalled and the notify function queued? Or would the 
EventGroup have to be signaled a second time for this new event to also 
become signaled?

Cheers,
Tom

Re: Creating Event in an EventGroup that has already been signaled

[Andrew Fish]

> On Jul 20, 2017, at 9:35 AM, Tomas Pilar (tpilar) <tpilar@solarflare.com> wrote:
> 
> What would be the state of that event post creation. Would it be immediately signalled and the notify function queued? Or would the EventGroup have to be signaled a second time for this new event to also become signaled?
> 

Tom,

Signaling an event inserts that event into a queue based on TPL. For GUIDed events the list of events is walked and any event that matches the GUID of the event group gets placed in the queue. 

https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Core/Dxe/Event/Event.c#L258 <https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Core/Dxe/Event/Event.c#L258>

The event is later dequeued and signaled. 

https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Core/Dxe/Event/Event.c#L165 <https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Core/Dxe/Event/Event.c#L165>

So basically you only signal the events that exists, including the event created to signal the event group. 

Thanks,

Andrew Fish


> Cheers,
> Tom
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org
> https://lists.01.org/mailman/listinfo/edk2-devel