Add Operator

Author: BenLauwens

src/SimJulia.jl

@@ -8,16 +8,20 @@ module SimJulia
   using DataStructures
 
   import Base.run, Base.now, Base.isless, Base.show
+  import Base.(&), Base.(|)
 
   export AbstractEvent
   export value, state, environment
   export Simulation
   export run, now, active_process
   export Event, Timeout
   export succeed, fail, append_callback, @callback, remove_callback
+  export Operator
+  export (&), (|)
 
   include("base.jl")
   include("simulations.jl")
   include("events.jl")
+  include("operators.jl")
 
 end

src/operators.jl

@@ -0,0 +1,58 @@
+struct StateValue
+  state :: EVENT_STATE
+  value :: Any
+  function StateValue(state::EVENT_STATE, value::Any=nothing)
+    new(state, value)
+  end
+end
+
+struct Operator <: AbstractEvent
+  bev :: BaseEvent
+  eval :: Function
+  function Operator(eval::Function, fev::AbstractEvent, events::AbstractEvent...)
+    env = environment(fev)
+    op = new(BaseEvent(env), eval)
+    event_state_values = Dict{AbstractEvent, StateValue}()
+    for ev in tuple(fev, events...)
+      event_state_values[ev] = StateValue(state(ev))
+      append_callback(check, ev, op, event_state_values)
+    end
+    op
+  end
+end
+
+function check(ev::AbstractEvent, op::Operator, event_state_values::Dict{AbstractEvent, StateValue})
+  val = value(ev)
+  if state(op) == idle
+    if isa(val, Exception)
+      schedule(op.bev, value=val)
+    else
+      event_state_values[ev] = StateValue(state(ev), val)
+      if op.eval(collect(values(event_state_values)))
+        schedule(op.bev, value=event_state_values)
+      end
+    end
+  elseif state(op) == scheduled
+    if isa(val, Exception)
+      schedule(op.bev, priority=typemax(Int8), value=val)
+    else
+      event_state_values[ev] = StateValue(state(ev), val)
+    end
+  end
+end
+
+function eval_and(state_values::Vector{StateValue})
+  return all(map((sv)->sv.state == triggered, state_values))
+end
+
+function eval_or(state_values::Vector{StateValue})
+  return any(map((sv)->sv.state == triggered, state_values))
+end
+
+function (&)(ev1::AbstractEvent, ev2::AbstractEvent)
+  return Operator(eval_and, ev1, ev2)
+end
+
+function (|)(ev1::AbstractEvent, ev2::AbstractEvent)
+  return Operator(eval_or, ev1, ev2)
+end

test/operators.jl

@@ -0,0 +1,39 @@
+using SimJulia
+
+function and_callback(ev::AbstractEvent)
+  println("Both events are triggered: $(value(ev))")
+end
+
+function or_callback(ev::AbstractEvent)
+  println("One of both events is triggered: $(value(ev))")
+end
+
+function or_callback_succeed(ev::AbstractEvent, ev2::AbstractEvent)
+  println("One of both events is triggered: $(value(ev))")
+  succeed(ev2)
+end
+
+function or_callback_fail(ev::AbstractEvent, ev2::AbstractEvent)
+  println("One of both events is triggered: $(value(ev))")
+  fail(ev2, TestException())
+end
+
+sim = Simulation()
+ev1 = Timeout(sim, 1)
+ev2 = Event(sim)
+@callback and_callback(ev1 & ev2)
+@callback or_callback_succeed(ev1 | ev2, ev2)
+run(sim)
+
+sim = Simulation()
+ev1 = Timeout(sim, 1, value=TestException())
+ev2 = Event(sim)
+@callback or_callback_fail(ev1 | ev2, ev2)
+@callback and_callback(ev1 & ev2)
+run(sim)
+
+sim = Simulation()
+ev1 = Timeout(sim)
+ev2 = Timeout(sim, value=TestException())
+@callback or_callback(ev1 | ev2)
+run(sim)

test/runtests.jl

@@ -3,6 +3,7 @@ testpath(f) = joinpath(dirname(@__FILE__), f)
 for test_file in [
   "base.jl",
   "simulations.jl",
-  "events.jl",]
+  "events.jl",
+  "operators.jl",]
   include(testpath(test_file))
 end