On Fri, Aug 20, 2010 at 3:06 PM, Christopher Dragert <[email protected]> wrote: > My SCXML is crashing when I try to run it and my debugging efforts have gone > for naught. The observable behaviour is as follows -- from the state > stationary, the state machine checks the guard on a transitions several > times, and then stops functioning. The cond is a method call using JEXL that > returns a boolean (I've tested this and found that the method does return on > a call leading to the crash, so the problem is not here). > > If the move transition is followed, then on eventual return to the stationary > state, the state machine will become unresponsive after a few checks of the > guard. > > With a listener I've determined that there is no state change, so if the > machine is running, the cond should be evaluated. My hunch is that the state > machine is silently failing -- how can i determine if this is the case? <snip/>
Not sure what crash means since I take it you are not observing any stack traces or ErrorReporter callbacks. It also seems that the state machine makes progress in some cases (as the "move" transition you mention above). Eventless transitions are only evaluated when an event is processed by Commons SCXML (be it external or internal). The cond method getting called number of times is a result of the processing of the external event followed by one or more internal events. Then the state machine may just be at rest between processing events (and therefore "silent"). > Are there any obvious mistakes that I'm making in my SCXML file? > <snap/> The indentation makes it slightly harder to read, but apart from the fact that some non-final states seem to be declared as final, I don't see much else (it would be good to remove all final="true" instances). Ofcourse, there are a number of eventless transitions (see above). Best if you could describe the expected behavior you are looking on (for a given scenario of current state, event fired etc.) -- what you are observing is clearer in your note. -Rahul > Any help would be appreciated, > > Chris Dragert > > ------ > SCXML file: > > <?xml version="1.0" encoding="ASCII"?> > <scxml xmlns="http://www.w3.org/2005/07/scxml"; > version="1.0" > initialstate="stationary"> > > <datamodel> > <data id="threatener" /> > <data id="move" expr="move" /> > </datamodel> > <state id="tracking" final="true"> > <initial> > <transition target="safe" /> > </initial> > > <transition event="i_see_player"> > <log expr="this.addPlayer(_eventdata)" /> > </transition> > > <transition event="i_dont_see_player"> > <log expr="this.removePlayer(_eventdata)" /> > </transition> > > <state id="safe" final="true"> > <initial> > <transition target="history" /> > </initial> > > <history type="deep" id="history"> > <transition target="stationary"/> > </history> > <state id="stationary" final="true"> > <transition cond="this.tooClose(this.getTheyApproachBuffer())" > target="threatened" /> > <transition event="move" target="moving" /> > </state> > > <state id="moving" final="true"> > <transition cond="this.tooClose(this.getWeApproachBuffer())" > target="threatened"> > <raise event="destination_unreachable" /> > </transition> > <transition event="destination_reached" target="stationary" /> > <transition event="destination_unreachable" target="stationary" /> > </state> > </state> > > <state id="threatened"> > <onentry> > <log expr="this.fleeTarget(threatener)" /> > <log expr="this.createEvent('move', destination)" /> > </onentry> > > <transition event="destination_reached" target="history" /> > <transition event="destination_unreachable" target="history" /> > </state> > > </state> > > </scxml> > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
