| RE: [dsdp-tml-dev] State machine problem |
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Hi Fabio! A simple solution to this problem could be: If we have 2 services (S1, S2) such that
both transition from A to B, this 2 can be executed in parallel. In other
cases, the machine could be left on an undecidable state. So two services are
allowed to run in parallel only if they have the same transition. A special
case is the one which the start state is the same as the end state. There are no other situations that
parallelism could be allowed. Daniel. From:
dsdp-tml-dev-bounces@xxxxxxxxxxx [mailto:dsdp-tml-dev-bounces@xxxxxxxxxxx] On Behalf Of Fabio Scramim Rigo Hello guys, I’ve found a potential problem source in the device
framework, related to the state machine control. Consider an instance that has 3 states (A, B and C) and 2
transitions (A->B, A->C). The instance is initially at state A. At the instance view, the services that execute both
transitions are enabled. Say we execute the service that transitions from A to
B. While the transition is ongoing, the device is neither in
state A or B, but at the state machine it is still considered in state A before
a result is available. Therefore the transition A->C is still enabled. What
happens if we execute A->C? I think it is necessary to define new rules for state
maintenance. One simple solution would be to disable all services while a
transition is ongoing, but there are cases in which two or more services can be
executed in parallel. Does anyone have ideas about what would be the most
effective algorithm to deal with a state machine generically, allowing
robustness and parallelism at the same time? Thanks and best regards, Fabio Rigo |