Files
smarm/tests/pg.rs
T

142 lines
4.1 KiB
Rust

//! Process-group tests that run under the scheduler: `join` installs a real
//! monitor on a live actor, and a real death drives eviction on next contact.
//! (Pure structural invariants live in the `pg` unit tests.)
use smarm::{channel, members, pick, run, spawn};
use smarm::{join, leave};
#[test]
fn join_then_members_lists_a_live_member() {
run(|| {
let (tx, rx) = channel::<()>();
let h = spawn(move || {
rx.recv().unwrap();
});
let pid = h.pid();
assert!(join("workers", pid), "first join is new");
assert!(!join("workers", pid), "second join is idempotent");
assert_eq!(members("workers"), vec![pid]);
assert_eq!(pick("workers"), Some(pid));
tx.send(()).unwrap();
h.join().unwrap();
});
}
#[test]
fn a_dead_actor_vanishes_from_every_group_it_joined() {
run(|| {
let (tx, rx) = channel::<()>();
let h = spawn(move || {
rx.recv().unwrap();
});
let pid = h.pid();
join("g1", pid);
join("g2", pid);
assert_eq!(members("g1"), vec![pid]);
assert_eq!(members("g2"), vec![pid]);
// Release and reap the actor. finalize_actor queues the Down to our
// monitors before unparking joiners, so by the time join() returns the
// Down is already waiting in the membership channel.
tx.send(()).unwrap();
h.join().unwrap();
// Drain-on-contact: touching g1 detects the death and sweeps the pid
// out of every group (g2 included), not just g1.
assert!(members("g1").is_empty(), "evicted from the touched group");
assert!(
members("g2").is_empty(),
"and swept from the untouched group"
);
assert_eq!(pick("g1"), None);
});
}
#[test]
fn pick_returns_none_when_the_only_member_is_dead() {
run(|| {
let (tx, rx) = channel::<()>();
let h = spawn(move || {
rx.recv().unwrap();
});
let pid = h.pid();
join("pool", pid);
tx.send(()).unwrap();
h.join().unwrap();
assert_eq!(pick("pool"), None);
assert!(members("pool").is_empty());
});
}
#[test]
fn live_members_survive_a_peers_death() {
run(|| {
let (tx_a, rx_a) = channel::<()>();
let (tx_b, rx_b) = channel::<()>();
let a = spawn(move || {
rx_a.recv().unwrap();
});
let b = spawn(move || {
rx_b.recv().unwrap();
});
join("svc", a.pid());
join("svc", b.pid());
// Kill a; b is still parked on its channel.
tx_a.send(()).unwrap();
a.join().unwrap();
assert_eq!(
members("svc"),
vec![b.pid()],
"only the dead peer is reaped"
);
assert_eq!(pick("svc"), Some(b.pid()));
tx_b.send(()).unwrap();
b.join().unwrap();
});
}
#[test]
fn leave_drops_a_membership_without_affecting_others() {
run(|| {
let (tx_a, rx_a) = channel::<()>();
let (tx_b, rx_b) = channel::<()>();
let a = spawn(move || {
rx_a.recv().unwrap();
});
let b = spawn(move || {
rx_b.recv().unwrap();
});
join("g", a.pid());
join("g", b.pid());
assert!(leave("g", a.pid()), "a was a member");
assert!(!leave("g", a.pid()), "leaving twice finds nothing");
assert_eq!(members("g"), vec![b.pid()]);
tx_a.send(()).unwrap();
tx_b.send(()).unwrap();
a.join().unwrap();
b.join().unwrap();
});
}
#[test]
fn joining_an_already_dead_pid_is_evicted_on_next_contact() {
run(|| {
let h = spawn(|| {});
let pid = h.pid();
h.join().unwrap(); // actor is finalized before we join it to anything
// monitor() on a gone pid queues a NoProc Down immediately, so the
// membership is reaped the next time the group is touched.
join("late", pid);
assert!(
members("late").is_empty(),
"dead-at-join member is reaped on read"
);
assert_eq!(pick("late"), None);
});
}