Information Technology Reference
In-Depth Information
Agent-based model Simulation engine (implementation)
Event
EventEvent
Action
ActionStartEvent
×
ActionEndEvent
This means, each model event is mapped onto a corresponding simu-
lator event. Each action of an agent (either sensor or effector action)
is mapped onto two simulator events, namely one for the start of an
action and one for the end of an action.
Algorithm 2
Main loop of the single-threaded event-driven simula-
tion engine
futureEvents = [
0 : StartEvent
]
now = timeOfFirstEvent(futureEvents)
while
futureEvents not empty AND now ¡ end
do
now = timeOfFirstEvent(futureEvents)
currentEvents = futureEvents.eventsAt(now)
for all
ActionEndEvent
e
in currentEvents
do
The action corresponding to event
e
could be executed success-
fully, therefore change model state accordingly
end for
for all
EnvironmentalEvent
e
in currentEvents
do
Update environment and check constraints
end for
for all
AgentEvent
e
in currentEvents
do
Relay event
e
to agents
end for
for all
ActionStartEvent
e
in currentEvents
do
Check constraints AND handle violated constraints
end for
end while
The main loop of the event-driven simulation engine is shown in
Algorithm 2. The
futureEvents
data structure holds all upcoming
events (timepoint and event). At the beginning,
futureEvents
is
initialized to hold the
StartEvent
which is sent to all agents at the
