mpstthree 0.1.17

A library implementing Multiparty Session Types for 2 or more participants
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148

use mpstthree::binary::struct_trait::{end::End, recv::Recv, send::Send, session::Session};
use mpstthree::generate;
use mpstthree::role::broadcast::RoleBroadcast;
use mpstthree::role::end::RoleEnd;

use rand::{thread_rng, Rng};

use std::boxed::Box;
use std::error::Error;

// See the folder scribble_protocols for the related Scribble protocol

// Create new MeshedChannels for four participants
generate!("rec_and_cancel", MeshedChannels, A, B, C);

type AtoCClose = End;
type AtoBClose = End;
type AtoBVideo = Send<i32, Recv<i32, End>>;
type AtoCVideo = Recv<i32, Send<i32, RecursAtoC>>;

type InitA = Recv<i32, Send<i32, RecursAtoC>>;

type BtoAClose = <AtoBClose as Session>::Dual;
type BtoCClose = End;
type BtoAVideo = <AtoBVideo as Session>::Dual;

type RecursAtoC = Recv<Branches0AtoC, End>;
type RecursBtoC = Recv<Branches0BtoC, End>;

enum Branches0AtoC {
    End(MeshedChannels<AtoBClose, AtoCClose, StackAEnd, NameA>),
    Video(MeshedChannels<AtoBVideo, AtoCVideo, StackAVideo, NameA>),
}
enum Branches0BtoC {
    End(MeshedChannels<BtoAClose, BtoCClose, StackBEnd, NameB>),
    Video(MeshedChannels<BtoAVideo, RecursBtoC, StackBVideo, NameB>),
}
type Choose0fromCtoA = Send<Branches0AtoC, End>;
type Choose0fromCtoB = Send<Branches0BtoC, End>;

type InitC = Send<i32, Recv<i32, Choose0fromCtoA>>;

// Stacks
type StackAEnd = RoleEnd;
type StackAVideo = RoleC<RoleB<RoleB<RoleC<RoleC<RoleEnd>>>>>;
type StackARecurs = RoleC<RoleEnd>;
type StackAInit = RoleC<RoleC<RoleC<RoleEnd>>>;

type StackBEnd = RoleEnd;
type StackBVideo = RoleA<RoleA<RoleC<RoleEnd>>>;
type StackBRecurs = RoleC<RoleEnd>;

type StackCRecurs = RoleBroadcast;
type StackCFull = RoleA<RoleA<StackCRecurs>>;

// Creating the MP sessions

// For C
type EndpointCRecurs = MeshedChannels<Choose0fromCtoA, Choose0fromCtoB, StackCRecurs, NameC>;
type EndpointCVideo = MeshedChannels<
    Send<i32, Recv<i32, Choose0fromCtoA>>,
    Choose0fromCtoB,
    RoleA<RoleA<StackCRecurs>>,
    NameC,
>;
type EndpointCFull = MeshedChannels<InitC, Choose0fromCtoB, StackCFull, NameC>;

// For A
type EndpointARecurs = MeshedChannels<End, RecursAtoC, StackARecurs, NameA>;
type EndpointAFull = MeshedChannels<End, InitA, StackAInit, NameA>;

// For B
type EndpointBRecurs = MeshedChannels<End, RecursBtoC, StackBRecurs, NameB>;

// Functions related to endpoints
fn server(s: EndpointBRecurs) -> Result<(), Box<dyn Error>> {
    offer_mpst!(s, {
        Branches0BtoC::End(s) => {
            s.close()
        },
        Branches0BtoC::Video(s) => {
            let (request, s) = s.recv()?;
            let s = s.send(request + 1)?;
            server(s)
        },
    })
}

fn authenticator(s: EndpointAFull) -> Result<(), Box<dyn Error>> {
    let (id, s) = s.recv()?;
    let s = s.send(id + 1)?;

    authenticator_recurs(s)
}

fn authenticator_recurs(s: EndpointARecurs) -> Result<(), Box<dyn Error>> {
    offer_mpst!(s, {
        Branches0AtoC::End(s) => {
            s.close()
        },
        Branches0AtoC::Video(s) => {
            let (request, s) = s.recv()?;
            let s = s.send(request + 1)?;
            let (video, s) = s.recv()?;
            let s = s.send(video + 1)?;
            authenticator_recurs(s)
        },
    })
}

fn client(s: EndpointCFull) -> Result<(), Box<dyn Error>> {
    let mut rng = thread_rng();
    let xs: Vec<i32> = (1..100).map(|_| rng.gen()).collect();

    let s = s.send(0)?;
    let (_, s) = s.recv()?;

    client_recurs(s, xs)
}

fn client_recurs(s: EndpointCRecurs, mut xs: Vec<i32>) -> Result<(), Box<dyn Error>> {
    match xs.pop() {
        Option::Some(_) => {
            let s: EndpointCVideo =
                choose_mpst_c_to_all!(s, Branches0AtoC::Video, Branches0BtoC::Video);

            let s = s.send(1)?;
            let (_, s) = s.recv()?;

            client_recurs(s, xs)
        }
        Option::None => {
            let s = choose_mpst_c_to_all!(s, Branches0AtoC::End, Branches0BtoC::End);

            s.close()
        }
    }
}

/////////////////////////////////////////

fn main() {
    let (thread_a, thread_s, thread_c) = fork_mpst(authenticator, server, client);

    thread_a.join().unwrap();
    thread_s.join().unwrap();
    thread_c.join().unwrap();
}