Re: [Qemu-devel] 0.9.0 Win32 Tap inferface PPC Guest issue

[Ely Soto]

Ok I located the source of the problem.

The code in main_loop_wait()
that uses WaitForMultipleObjects
will only service one object that woke it up.

What is occuring is that the host_alarm
timer is being serviced anytime the tap_semaphore is also signaled, therefore
the tap callback function is
never called while at the same time
the tap_semaphore count is decremented. This guarantees that the callback
function will never get services if that particular timing continues.

This is likely something that won't
occur on every system because of the nature of the timing, but it is a
problem.

I'm working on a better fix as right
now my solution is to poll all the objects after a wakeup to see who really
is signaled.
In order to do that you must use an
Event Object in Manual Reset Mode.

vl.c

void
main_loop_wait(int
timeout)
...
        WaitObjects
*w = &wait_objects;
        
        ret = WaitForMultipleObjects(w->num,
w->events, FALSE, timeout);
        if (WAIT_OBJECT_0
+ 0 <= ret && ret <= WAIT_OBJECT_0 + w->num - 1) {
         
  if (w->func[ret - WAIT_OBJECT_0])
         
      w->func[ret - WAIT_OBJECT_0](w->opaque[ret -
WAIT_OBJECT_0]);
        } else
if (ret == WAIT_TIMEOUT) {
        } else
{
         
  err = GetLastError();
         
  fprintf(stderr, "Wait error %d %d\n", ret, err);
        }
...



Ely Soto

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