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use std::sync::atomic::Ordering::SeqCst;
use std::sync::atomic::{AtomicBool, AtomicUsize};
use std::sync::{Arc, Mutex};
use crossbeam_deque::Steal::{Empty, Success};
use crossbeam_deque::{Injector, Worker};
use crossbeam_utils::thread::scope;
use rand::Rng;
#[test]
fn smoke() {
let q = Injector::new();
assert_eq!(q.steal(), Empty);
q.push(1);
q.push(2);
assert_eq!(q.steal(), Success(1));
assert_eq!(q.steal(), Success(2));
assert_eq!(q.steal(), Empty);
q.push(3);
assert_eq!(q.steal(), Success(3));
assert_eq!(q.steal(), Empty);
}
#[test]
fn is_empty() {
let q = Injector::new();
assert!(q.is_empty());
q.push(1);
assert!(!q.is_empty());
q.push(2);
assert!(!q.is_empty());
let _ = q.steal();
assert!(!q.is_empty());
let _ = q.steal();
assert!(q.is_empty());
q.push(3);
assert!(!q.is_empty());
let _ = q.steal();
assert!(q.is_empty());
}
#[test]
fn spsc() {
#[cfg(miri)]
const COUNT: usize = 500;
#[cfg(not(miri))]
const COUNT: usize = 100_000;
let q = Injector::new();
scope(|scope| {
scope.spawn(|_| {
for i in 0..COUNT {
loop {
if let Success(v) = q.steal() {
assert_eq!(i, v);
break;
}
#[cfg(miri)]
std::hint::spin_loop();
}
}
assert_eq!(q.steal(), Empty);
});
for i in 0..COUNT {
q.push(i);
}
})
.unwrap();
}
#[test]
fn mpmc() {
#[cfg(miri)]
const COUNT: usize = 500;
#[cfg(not(miri))]
const COUNT: usize = 25_000;
const THREADS: usize = 4;
let q = Injector::new();
let v = (0..COUNT).map(|_| AtomicUsize::new(0)).collect::<Vec<_>>();
scope(|scope| {
for _ in 0..THREADS {
scope.spawn(|_| {
for i in 0..COUNT {
q.push(i);
}
});
}
for _ in 0..THREADS {
scope.spawn(|_| {
for _ in 0..COUNT {
loop {
if let Success(n) = q.steal() {
v[n].fetch_add(1, SeqCst);
break;
}
#[cfg(miri)]
std::hint::spin_loop();
}
}
});
}
})
.unwrap();
for c in v {
assert_eq!(c.load(SeqCst), THREADS);
}
}
#[test]
fn stampede() {
const THREADS: usize = 8;
#[cfg(miri)]
const COUNT: usize = 500;
#[cfg(not(miri))]
const COUNT: usize = 50_000;
let q = Injector::new();
for i in 0..COUNT {
q.push(Box::new(i + 1));
}
let remaining = Arc::new(AtomicUsize::new(COUNT));
scope(|scope| {
for _ in 0..THREADS {
let remaining = remaining.clone();
let q = &q;
scope.spawn(move |_| {
let mut last = 0;
while remaining.load(SeqCst) > 0 {
if let Success(x) = q.steal() {
assert!(last < *x);
last = *x;
remaining.fetch_sub(1, SeqCst);
}
}
});
}
let mut last = 0;
while remaining.load(SeqCst) > 0 {
if let Success(x) = q.steal() {
assert!(last < *x);
last = *x;
remaining.fetch_sub(1, SeqCst);
}
}
})
.unwrap();
}
#[test]
fn stress() {
const THREADS: usize = 8;
#[cfg(miri)]
const COUNT: usize = 500;
#[cfg(not(miri))]
const COUNT: usize = 50_000;
let q = Injector::new();
let done = Arc::new(AtomicBool::new(false));
let hits = Arc::new(AtomicUsize::new(0));
scope(|scope| {
for _ in 0..THREADS {
let done = done.clone();
let hits = hits.clone();
let q = &q;
scope.spawn(move |_| {
let w2 = Worker::new_fifo();
while !done.load(SeqCst) {
if let Success(_) = q.steal() {
hits.fetch_add(1, SeqCst);
}
let _ = q.steal_batch(&w2);
if let Success(_) = q.steal_batch_and_pop(&w2) {
hits.fetch_add(1, SeqCst);
}
while w2.pop().is_some() {
hits.fetch_add(1, SeqCst);
}
}
});
}
let mut rng = rand::thread_rng();
let mut expected = 0;
while expected < COUNT {
if rng.gen_range(0..3) == 0 {
while let Success(_) = q.steal() {
hits.fetch_add(1, SeqCst);
}
} else {
q.push(expected);
expected += 1;
}
}
while hits.load(SeqCst) < COUNT {
while let Success(_) = q.steal() {
hits.fetch_add(1, SeqCst);
}
}
done.store(true, SeqCst);
})
.unwrap();
}
#[cfg_attr(miri, ignore)] // Miri is too slow
#[test]
fn no_starvation() {
const THREADS: usize = 8;
const COUNT: usize = 50_000;
let q = Injector::new();
let done = Arc::new(AtomicBool::new(false));
let mut all_hits = Vec::new();
scope(|scope| {
for _ in 0..THREADS {
let done = done.clone();
let hits = Arc::new(AtomicUsize::new(0));
all_hits.push(hits.clone());
let q = &q;
scope.spawn(move |_| {
let w2 = Worker::new_fifo();
while !done.load(SeqCst) {
if let Success(_) = q.steal() {
hits.fetch_add(1, SeqCst);
}
let _ = q.steal_batch(&w2);
if let Success(_) = q.steal_batch_and_pop(&w2) {
hits.fetch_add(1, SeqCst);
}
while w2.pop().is_some() {
hits.fetch_add(1, SeqCst);
}
}
});
}
let mut rng = rand::thread_rng();
let mut my_hits = 0;
loop {
for i in 0..rng.gen_range(0..COUNT) {
if rng.gen_range(0..3) == 0 && my_hits == 0 {
while let Success(_) = q.steal() {
my_hits += 1;
}
} else {
q.push(i);
}
}
if my_hits > 0 && all_hits.iter().all(|h| h.load(SeqCst) > 0) {
break;
}
}
done.store(true, SeqCst);
})
.unwrap();
}
#[test]
fn destructors() {
#[cfg(miri)]
const THREADS: usize = 2;
#[cfg(not(miri))]
const THREADS: usize = 8;
#[cfg(miri)]
const COUNT: usize = 500;
#[cfg(not(miri))]
const COUNT: usize = 50_000;
#[cfg(miri)]
const STEPS: usize = 100;
#[cfg(not(miri))]
const STEPS: usize = 1000;
struct Elem(usize, Arc<Mutex<Vec<usize>>>);
impl Drop for Elem {
fn drop(&mut self) {
self.1.lock().unwrap().push(self.0);
}
}
let q = Injector::new();
let dropped = Arc::new(Mutex::new(Vec::new()));
let remaining = Arc::new(AtomicUsize::new(COUNT));
for i in 0..COUNT {
q.push(Elem(i, dropped.clone()));
}
scope(|scope| {
for _ in 0..THREADS {
let remaining = remaining.clone();
let q = &q;
scope.spawn(move |_| {
let w2 = Worker::new_fifo();
let mut cnt = 0;
while cnt < STEPS {
if let Success(_) = q.steal() {
cnt += 1;
remaining.fetch_sub(1, SeqCst);
}
let _ = q.steal_batch(&w2);
if let Success(_) = q.steal_batch_and_pop(&w2) {
cnt += 1;
remaining.fetch_sub(1, SeqCst);
}
while w2.pop().is_some() {
cnt += 1;
remaining.fetch_sub(1, SeqCst);
}
}
});
}
for _ in 0..STEPS {
if let Success(_) = q.steal() {
remaining.fetch_sub(1, SeqCst);
}
}
})
.unwrap();
let rem = remaining.load(SeqCst);
assert!(rem > 0);
{
let mut v = dropped.lock().unwrap();
assert_eq!(v.len(), COUNT - rem);
v.clear();
}
drop(q);
{
let mut v = dropped.lock().unwrap();
assert_eq!(v.len(), rem);
v.sort_unstable();
for pair in v.windows(2) {
assert_eq!(pair[0] + 1, pair[1]);
}
}
}