+ concurrency?
Message passing concurrency
Choreographies are a way of describing communicating systems as global programs
A
B
A
B
A.x -> B.x
A.x -> B.x
A
Send("B",x)
B
x = Receive("A")
A.x -> B.x
let y@A = foo()
let w@B = bar()
A
Send("B",x)
y = foo()
B
x = Receive("A")
w = bar()
A.x -> B.x
let y@A = foo()
let w@B = bar()
A.x -> B.x
let y@A = foo()
let w@B = bar()
if y@A
A->B[T]
...
else
A->B[F]
...
A.x -> B.x
let y@A = crunch()
let w@B = crunch()
if y@A
A->B[T]
...
else
A->B[F]
...
A
if y
Choose("B",T)
...
else
Choose("B",F)
...
B
if Choice("A")
...
else
...
A.x -> B.x
B.y -> C.y
...
A.x -> B.x
B.y -> C.y
...
Deadlock-freedom
Communication
A.x -> B.y;CCommunication
SA.x -> B.y;CCommunication
S(A,x) = d
A.x -> B.y;CCommunication
A.x -> B.y;C
S[(B,y)|->d]Communication
S[(B,y)|->d]C
A.x -> B.x
B.y -> C.y
...
A.x -> B.x
B.y -> C.y
...
EPN
EPN
Selection
Payload
Closure
?