yog 0.0.47

yog: the standalone server for litany loops — the world, the balls and the conversations, behind one wire
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
149
150
151
152
153

//! The engine's one table (STORIES S14-T8): a boot answers a deposit.
//!
//! This is the whole server claim in one test — no window, no display, no
//! face — and it is the test main.rs could never carry, which is why the
//! assembly moved out of it. Everything the engine used to hand a window (the
//! asker, the poster, the follow lane, the §8.5 searcher) went with the window
//! (bl-7942); what a seat gets now is a socket, and the listener's own tests
//! are where that is proven.

use super::*;
use crate::boundary::deposit;
use crate::test_support::world_under;
use crate::ui_state::Clock;
use serde_json::json;
use std::time::{Duration, Instant};
use tempfile::tempdir;

/// A clock that states a chosen wall time — [`FakeClock`](crate::test_support::FakeClock)
/// stamps a placeholder, and the §5.2 sweep reads the stamp as a unix second.
struct AtClock(i64);

impl Clock for AtClock {
    fn now(&self) -> Instant {
        Instant::now()
    }
    fn stamp(&self) -> String {
        self.0.to_string()
    }
}

/// The rung: boot the engine into a hermetic world, drop a gesture in its
/// inbox, and read the answer back. Every thread a running yog has is up, and
/// none of them is a frame.
#[test]
fn a_booted_engine_answers_a_deposit_and_stops_on_drop() {
    let root = tempdir().unwrap();
    let world = world_under(root.path());
    // A boot listens on the default request — `127.0.0.1:0`, a kernel-chosen
    // port (bl-dc14) — so nothing here contends with the operator's own
    // running window, and nothing needs seeding to avoid it.
    // A staging dir older than the §5.2 horizon: the sweep is the engine's, so
    // booting one is what drops it.
    let stale = world.yog_stage_root().join("nonce");
    std::fs::create_dir_all(&stale).unwrap();
    let far_future = 1_000_000_000_000;
    let state_root = world.yog_state_root();
    deposit::deposit(&state_root, "e-1", &json!({"op": "attention"})).unwrap();

    let engine = Engine::boot(&world, &[], Arc::new(AtClock(far_future))).expect("booted");
    assert!(!stale.exists(), "the §5.2 startup sweep is the engine's");
    assert_eq!(
        engine.model.ui_json_path(),
        state_root.join("ui.json"),
        "the model is rooted in the world it was booted into"
    );

    let deadline = Instant::now() + Duration::from_secs(10);
    let reply = loop {
        if let Some(reply) = deposit::read_reply(&state_root, "e-1") {
            break reply;
        }
        assert!(Instant::now() < deadline, "the engine answered no deposit");
        std::thread::sleep(Duration::from_millis(10));
    };
    assert_eq!(reply["ok"], true);
    assert_eq!(reply["kind"], "attention", "the §6 queue, headless");
    assert_eq!(
        reply["rows"].as_array().map(Vec::len),
        Some(0),
        "an empty world asks nothing of anyone"
    );
    drop(engine); // every thread stops and joins — the Drop is the shutdown
}

/// **An engine that cannot get its wire up is not an engine** (bl-1d9b,
/// reversing bl-dc14's narrowing): the boot refuses, naming the address, and
/// nothing is consumed — the deposit sitting in the inbox is still sitting
/// there afterwards.
///
/// This used to be the opposite assertion: the refusal was said on stderr and
/// the engine ran on, on the argument that a deposit still converges through
/// the inbox so only a seat is shut out. The seat IS the face since bl-7942, so
/// what that argument buys is a process that answers nobody, drains the world's
/// gesture inbox and looks healthy — the half-engine whose second `inv-N`
/// namespace handed one model another invocation's capture.
#[test]
fn a_boot_whose_stated_address_cannot_bind_refuses_and_consumes_nothing() {
    let root = tempdir().unwrap();
    let world = world_under(root.path());
    let dir = crate::wire::material::dir(&world);
    crate::test_support::wire::mint(&dir);
    // An address no socket can take, so the listener's bind is the thing that
    // fails — not the mint, whose own refusal is `wire::tests`'.
    std::fs::write(
        dir.join(crate::wire::material::ADDRESS),
        "256.256.256.256:1\n",
    )
    .unwrap();
    let state_root = world.yog_state_root();
    deposit::deposit(&state_root, "e-2", &json!({"op": "attention"})).unwrap();

    let refusal = Engine::boot(&world, &[], Arc::new(AtClock(0)))
        .err()
        .expect("a yog that cannot listen is not an engine");
    assert!(refusal.starts_with("wire: "), "{refusal}");
    assert!(
        refusal.contains("256.256.256.256:1"),
        "it names the address: {refusal}"
    );
    assert!(
        deposit::read_reply(&state_root, "e-2").is_none(),
        "a boot that refuses has not consumed a gesture"
    );
}

/// **One world has one engine** (bl-1d9b). The second boot on a world the first
/// still holds is refused before it spawns a consumer, so there is never a
/// second drain of one `gestures/` inbox and never a second `inv-N` namespace
/// behind it. The first engine keeps answering throughout.
#[test]
fn a_second_engine_on_one_world_refuses_while_the_first_keeps_answering() {
    let root = tempdir().unwrap();
    let world = world_under(root.path());
    let state_root = world.yog_state_root();
    let first = Engine::boot(&world, &[], Arc::new(AtClock(0))).expect("the first engine");

    let refusal = Engine::boot(&world, &[], Arc::new(AtClock(0)))
        .err()
        .expect("the second is refused");
    assert!(refusal.contains("one world has one engine"), "{refusal}");

    deposit::deposit(&state_root, "e-3", &json!({"op": "attention"})).unwrap();
    let deadline = Instant::now() + Duration::from_secs(10);
    let reply = loop {
        if let Some(reply) = deposit::read_reply(&state_root, "e-3") {
            break reply;
        }
        assert!(Instant::now() < deadline, "the one engine still answers");
        std::thread::sleep(Duration::from_millis(10));
    };
    assert_eq!(reply["ok"], true);
    drop(first);
    // The world frees when its engine goes — modulo the one window no advisory
    // lock can close (see `sole`): a `fork` on another thread at that instant
    // copies the descriptor, and the copy goes at that child's own `exec`. The
    // wait is that window and nothing else, which is why it is spelled in
    // milliseconds; the fact under test is that the lock is released at all.
    let deadline = Instant::now() + Duration::from_secs(5);
    while crate::engine::sole::take(&state_root).is_err() {
        assert!(Instant::now() < deadline, "the world never freed");
        std::thread::sleep(Duration::from_millis(20));
    }
}