Preemption and test403c

Hi there,

there has been much back and forth with regard to preemption, but as far as I understand it, if two transitions have conflicting exit sets, we basically take the first one in document order? If that's the case, then I cannot see how test403c is supposed to pass (excerpt):

<state id="s0" initial="p0">
<onentry>
<raise event="event1"/>
<send event="timeout" delay="100s"/>
</onentry>
<transition event="event2" target="fail"/>
<transition event="timeout" target="fail"/>

<parallel id="p0">
<state id="p0s1">
<transition event="event1"/>
<transition event="event2"/>
</state>
<state id="p0s2">
<transition event="event1" target="p0s1">
<raise event="event2"/>
</transition>
</state>
<state id="p0s3">
<!-- this transition should be blocked by the one in p0s2-->
<transition event="event1" target="fail"/>
<!-- this transition will preempt the one that p0s2 inherits from an ancestor  -->
<transition event="event2" target="s1"/>
</state>
<state id="p0s4">
<!-- this transition never gets preempted, should fire twice -->
<transition event="*">
<assign location="Var1" expr="Var1 + 1"/>
</transition>
</state>
</parallel>
</state>

At some point after event1 was processed and our configuration is {s0, p0 p0s1, p0s2, p0s3, p0s4} and event2 was raised. I cannot see how the transition to s1 in p0s3 is supposed to preempt the one to fail in s0.

<transition event="event2" target="fail"/> and <transition event="event2" target="s1"/> clearly have conflicting exit sets, but still the transition to fail comes first in document order. What am I missing here? I'd appreciate it, if it can be solved with the functionality described in the current draft 6 as I just want to get the tests working for now.

Relevant pseudocode is:

function selectTransitions(event):
    enabledTransitions = new OrderedSet()
    atomicStates = configuration.toList().filter(isAtomicState).sort(documentOrder)
    for state in atomicStates:
        loop: for s in [state].append(getProperAncestors(state, null)):
            for t in s.transition:
                if t.event and nameMatch(t.event, event.name) and conditionMatch(t):
                    enabledTransitions.add(t)
                    break loop
    enabledTransitions = filterPreempted(enabledTransitions)
    return enabledTransitions


This will iterate the basic configuration in document order and walk up each ancestor chain until there is a transition to add:

p0s1: already has a matching transition <transition event="event2"/>
p0s2: first matching transition is the one to fail in s0
p0s3: already has a matching transition to s1, which is the one we want
p0s4: already has a matching transition as well

So the enabledTransitions contains the following transitions before calling filterPreempted:
from p0s1: <transition event="event2"/> (type1)
from p0s2: <transition event="event2" target="fail"/> (type3)
from p0s3: <transition event="event2" target="s1"/> (type3)
from p0s4: <transition event="*"> (type1)

Document order is:
from p0s2: <transition event="event2" target="fail"/> (type3)
from p0s1: <transition event="event2"/> (type1)
from p0s3: <transition event="event2" target="s1"/> (type3)
from p0s4: <transition event="*"> (type1)

As the draft still specifies "Type 3 transitions preempt all other transitions" the transition to s1 will always get preempted by the transition to fail. What am I missing here?

Sorry for not referring to the latest proposals with regard to preemption, but the situation is still rather opaque and at this point I just want the tests to pass.
  Stefan