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use crate::sync::atomic::{AtomicUsize, Ordering};
use crate::sync::mpsc::channel;
use crate::sync::{Arc, RwLock, RwLockReadGuard, TryLockError};
use crate::thread;
use rand::{self, Rng};
#[derive(Eq, PartialEq, Debug)]
struct NonCopy(i32);
#[test]
fn smoke() {
let l = RwLock::new(());
drop(l.read().unwrap());
drop(l.write().unwrap());
drop((l.read().unwrap(), l.read().unwrap()));
drop(l.write().unwrap());
}
#[test]
fn frob() {
const N: u32 = 10;
const M: usize = if cfg!(miri) { 100 } else { 1000 };
let r = Arc::new(RwLock::new(()));
let (tx, rx) = channel::<()>();
for _ in 0..N {
let tx = tx.clone();
let r = r.clone();
thread::spawn(move || {
let mut rng = rand::thread_rng();
for _ in 0..M {
if rng.gen_bool(1.0 / (N as f64)) {
drop(r.write().unwrap());
} else {
drop(r.read().unwrap());
}
}
drop(tx);
});
}
drop(tx);
let _ = rx.recv();
}
#[test]
fn test_rw_arc_poison_wr() {
let arc = Arc::new(RwLock::new(1));
let arc2 = arc.clone();
let _: Result<(), _> = thread::spawn(move || {
let _lock = arc2.write().unwrap();
panic!();
})
.join();
assert!(arc.read().is_err());
}
#[test]
fn test_rw_arc_poison_ww() {
let arc = Arc::new(RwLock::new(1));
assert!(!arc.is_poisoned());
let arc2 = arc.clone();
let _: Result<(), _> = thread::spawn(move || {
let _lock = arc2.write().unwrap();
panic!();
})
.join();
assert!(arc.write().is_err());
assert!(arc.is_poisoned());
}
#[test]
fn test_rw_arc_no_poison_rr() {
let arc = Arc::new(RwLock::new(1));
let arc2 = arc.clone();
let _: Result<(), _> = thread::spawn(move || {
let _lock = arc2.read().unwrap();
panic!();
})
.join();
let lock = arc.read().unwrap();
assert_eq!(*lock, 1);
}
#[test]
fn test_rw_arc_no_poison_rw() {
let arc = Arc::new(RwLock::new(1));
let arc2 = arc.clone();
let _: Result<(), _> = thread::spawn(move || {
let _lock = arc2.read().unwrap();
panic!()
})
.join();
let lock = arc.write().unwrap();
assert_eq!(*lock, 1);
}
#[test]
fn test_rw_arc() {
let arc = Arc::new(RwLock::new(0));
let arc2 = arc.clone();
let (tx, rx) = channel();
thread::spawn(move || {
let mut lock = arc2.write().unwrap();
for _ in 0..10 {
let tmp = *lock;
*lock = -1;
thread::yield_now();
*lock = tmp + 1;
}
tx.send(()).unwrap();
});
// Readers try to catch the writer in the act
let mut children = Vec::new();
for _ in 0..5 {
let arc3 = arc.clone();
children.push(thread::spawn(move || {
let lock = arc3.read().unwrap();
assert!(*lock >= 0);
}));
}
// Wait for children to pass their asserts
for r in children {
assert!(r.join().is_ok());
}
// Wait for writer to finish
rx.recv().unwrap();
let lock = arc.read().unwrap();
assert_eq!(*lock, 10);
}
#[test]
fn test_rw_arc_access_in_unwind() {
let arc = Arc::new(RwLock::new(1));
let arc2 = arc.clone();
let _ = thread::spawn(move || -> () {
struct Unwinder {
i: Arc<RwLock<isize>>,
}
impl Drop for Unwinder {
fn drop(&mut self) {
let mut lock = self.i.write().unwrap();
*lock += 1;
}
}
let _u = Unwinder { i: arc2 };
panic!();
})
.join();
let lock = arc.read().unwrap();
assert_eq!(*lock, 2);
}
#[test]
fn test_rwlock_unsized() {
let rw: &RwLock<[i32]> = &RwLock::new([1, 2, 3]);
{
let b = &mut *rw.write().unwrap();
b[0] = 4;
b[2] = 5;
}
let comp: &[i32] = &[4, 2, 5];
assert_eq!(&*rw.read().unwrap(), comp);
}
#[test]
fn test_rwlock_try_write() {
let lock = RwLock::new(0isize);
let read_guard = lock.read().unwrap();
let write_result = lock.try_write();
match write_result {
Err(TryLockError::WouldBlock) => (),
Ok(_) => assert!(false, "try_write should not succeed while read_guard is in scope"),
Err(_) => assert!(false, "unexpected error"),
}
drop(read_guard);
}
#[test]
fn test_into_inner() {
let m = RwLock::new(NonCopy(10));
assert_eq!(m.into_inner().unwrap(), NonCopy(10));
}
#[test]
fn test_into_inner_drop() {
struct Foo(Arc<AtomicUsize>);
impl Drop for Foo {
fn drop(&mut self) {
self.0.fetch_add(1, Ordering::SeqCst);
}
}
let num_drops = Arc::new(AtomicUsize::new(0));
let m = RwLock::new(Foo(num_drops.clone()));
assert_eq!(num_drops.load(Ordering::SeqCst), 0);
{
let _inner = m.into_inner().unwrap();
assert_eq!(num_drops.load(Ordering::SeqCst), 0);
}
assert_eq!(num_drops.load(Ordering::SeqCst), 1);
}
#[test]
fn test_into_inner_poison() {
let m = Arc::new(RwLock::new(NonCopy(10)));
let m2 = m.clone();
let _ = thread::spawn(move || {
let _lock = m2.write().unwrap();
panic!("test panic in inner thread to poison RwLock");
})
.join();
assert!(m.is_poisoned());
match Arc::try_unwrap(m).unwrap().into_inner() {
Err(e) => assert_eq!(e.into_inner(), NonCopy(10)),
Ok(x) => panic!("into_inner of poisoned RwLock is Ok: {x:?}"),
}
}
#[test]
fn test_get_mut() {
let mut m = RwLock::new(NonCopy(10));
*m.get_mut().unwrap() = NonCopy(20);
assert_eq!(m.into_inner().unwrap(), NonCopy(20));
}
#[test]
fn test_get_mut_poison() {
let m = Arc::new(RwLock::new(NonCopy(10)));
let m2 = m.clone();
let _ = thread::spawn(move || {
let _lock = m2.write().unwrap();
panic!("test panic in inner thread to poison RwLock");
})
.join();
assert!(m.is_poisoned());
match Arc::try_unwrap(m).unwrap().get_mut() {
Err(e) => assert_eq!(*e.into_inner(), NonCopy(10)),
Ok(x) => panic!("get_mut of poisoned RwLock is Ok: {x:?}"),
}
}
#[test]
fn test_read_guard_covariance() {
fn do_stuff<'a>(_: RwLockReadGuard<'_, &'a i32>, _: &'a i32) {}
let j: i32 = 5;
let lock = RwLock::new(&j);
{
let i = 6;
do_stuff(lock.read().unwrap(), &i);
}
drop(lock);
}
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