implement take!

Author: Krastanov

src/ConcurrentSim.jl

@@ -7,7 +7,7 @@ module ConcurrentSim
   using Dates
   using ResumableFunctions
 
-  import Base: run, isless, show, yield, get, put!, isready, islocked, unlock, lock, trylock, &, |
+  import Base: run, isless, show, yield, get, put!, take!, isready, islocked, unlock, lock, trylock, &, |
   import Dates: now
 
   export AbstractEvent, Environment, value, state, environment

src/resources/containers.jl

@@ -112,3 +112,5 @@ true
 ```
 """
 islocked(c::Container) = c.level==c.capacity
+
+take!(::Container, args...) = error("There is no well defined `take!` for `Container`. Instead of attempting `take!` consider using `unlock(::Container)` or use a `Store` instead of a `Resource` or `Container`. Think of `Resource` and `Container` as locks and of `Store` as channels. They block only if empty (on taking) or full (on storing).")

src/resources/stores.jl

@@ -103,3 +103,10 @@ islocked(sto::Store) = sto.load==sto.capacity
 unlock(::Store) = error("There is no well defined way to \"unlock\" a store. Instead of attempting `unlock` consider using `pop!(::Store)` or use a `Resource` instead of a `Store`.")
 lock(::Store) = error("There is no well defined way to \"lock\" a store. Instead of attempting `lock` consider using `put!(::Store, ...)` or use a `Resource` instead of a `Store`.")
 trylock(::Store) = error("There is no well defined way to \"lock\" a store. Instead of attempting `lock` consider using `put!(::Store, ...)` or use a `Resource` instead of a `Store`.")
+
+"""
+    take!(::Store)
+
+An alias for `get(::Store)` for easier interoperability with the `Base.Channel` interface. Blocks if the store is empty.
+"""
+take!(sto::Store{T}, filter::Function=get_any_item; priority::Int=0) where {T} = get(sto, filter; priority)

test/test_resources_containers.jl

@@ -59,3 +59,5 @@ con = Container(sim, 10.0; level=5.0)
 @process my_consumer(sim, con)
 @process my_producer(sim, con)
 run(sim)
+
+@test_throws ErrorException take!(con)

test/test_resources_stores.jl

@@ -9,7 +9,7 @@ end
   for j in 1:10
     @yield timeout(sim, rand())
     println("$(now(sim)), consumer is demanding object")
-    obj = @yield get(sto)
+    obj = @yield take!(sto)
     println("$(now(sim)), consumer is being served with object ", obj.i)
   end
 end

test/test_resources_stores_deprecated.jl

@@ -0,0 +1,30 @@
+using ConcurrentSim
+using ResumableFunctions
+
+struct StoreObject
+  i :: Int
+end
+
+@resumable function my_consumer(sim::Simulation, sto::Store)
+  for j in 1:10
+    @yield timeout(sim, rand())
+    println("$(now(sim)), consumer is demanding object")
+    obj = @yield get(sto) # "unofficially" deprecated
+    println("$(now(sim)), consumer is being served with object ", obj.i)
+  end
+end
+
+@resumable function my_producer(sim::Simulation, sto::Store)
+  for j in 1:10
+    println("$(now(sim)), producer is offering object $j")
+    @yield put!(sto, StoreObject(j))
+    println("$(now(sim)), producer is being served")
+    @yield timeout(sim, 2*rand())
+  end
+end
+
+sim = Simulation()
+sto = Store{StoreObject}(sim)
+@process my_consumer(sim, sto)
+@process my_producer(sim, sto)
+run(sim)