On Tue, Apr 19, 2005 at 12:51:17PM +0200, Manuel Bouyer wrote:
> On Tue, Apr 19, 2005 at 11:43:04AM +0100, Christian Limpach wrote:
> > From: "Manuel Bouyer" <bouyer@antioche.lip6.fr>
> > >Hum, I need to look at this again. From what I remember, if I leaved
> > >the events blocked, HYPERVISOR_yield() would never return.
> > >But maybe I had something else wrong in my code.
> > 
> > HYPERVISOR_yield() should be used to yield the cpu, i.e. other domains will 
> > get to run and the current domain gets put on the runqueue and will run 
> > again at some point.  HYPERVISOR_block() will also yield the cpu but only 
> > returns once there's an event that can be delivered.
> 
> Will HYPERVISOR_block() return when there is an event pending, even if
> evtchn_upcall_mask is nonzero ?

yes, HYPERVISOR_block() will reenable events in a race-free manner, i.e.
you want to call HYPERVISOR_block() with events disabled and it will return
immediately if there are already pending events.

    christian