aboutsummaryrefslogtreecommitdiff
path: root/vendor/once_cell/tests/it/sync_once_cell.rs
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/once_cell/tests/it/sync_once_cell.rs')
-rw-r--r--vendor/once_cell/tests/it/sync_once_cell.rs309
1 files changed, 309 insertions, 0 deletions
diff --git a/vendor/once_cell/tests/it/sync_once_cell.rs b/vendor/once_cell/tests/it/sync_once_cell.rs
new file mode 100644
index 0000000..252adea
--- /dev/null
+++ b/vendor/once_cell/tests/it/sync_once_cell.rs
@@ -0,0 +1,309 @@
+use std::{
+ sync::atomic::{AtomicUsize, Ordering::SeqCst},
+ thread::scope,
+};
+
+#[cfg(feature = "std")]
+use std::sync::Barrier;
+
+#[cfg(not(feature = "std"))]
+use core::cell::Cell;
+
+use once_cell::sync::{Lazy, OnceCell};
+
+#[test]
+fn once_cell() {
+ let c = OnceCell::new();
+ assert!(c.get().is_none());
+ scope(|s| {
+ s.spawn(|| {
+ c.get_or_init(|| 92);
+ assert_eq!(c.get(), Some(&92));
+ });
+ });
+ c.get_or_init(|| panic!("Kabom!"));
+ assert_eq!(c.get(), Some(&92));
+}
+
+#[test]
+fn once_cell_with_value() {
+ static CELL: OnceCell<i32> = OnceCell::with_value(12);
+ assert_eq!(CELL.get(), Some(&12));
+}
+
+#[test]
+fn once_cell_get_mut() {
+ let mut c = OnceCell::new();
+ assert!(c.get_mut().is_none());
+ c.set(90).unwrap();
+ *c.get_mut().unwrap() += 2;
+ assert_eq!(c.get_mut(), Some(&mut 92));
+}
+
+#[test]
+fn once_cell_get_unchecked() {
+ let c = OnceCell::new();
+ c.set(92).unwrap();
+ unsafe {
+ assert_eq!(c.get_unchecked(), &92);
+ }
+}
+
+#[test]
+fn once_cell_drop() {
+ static DROP_CNT: AtomicUsize = AtomicUsize::new(0);
+ struct Dropper;
+ impl Drop for Dropper {
+ fn drop(&mut self) {
+ DROP_CNT.fetch_add(1, SeqCst);
+ }
+ }
+
+ let x = OnceCell::new();
+ scope(|s| {
+ s.spawn(|| {
+ x.get_or_init(|| Dropper);
+ assert_eq!(DROP_CNT.load(SeqCst), 0);
+ drop(x);
+ });
+ });
+ assert_eq!(DROP_CNT.load(SeqCst), 1);
+}
+
+#[test]
+fn once_cell_drop_empty() {
+ let x = OnceCell::<String>::new();
+ drop(x);
+}
+
+#[test]
+fn clone() {
+ let s = OnceCell::new();
+ let c = s.clone();
+ assert!(c.get().is_none());
+
+ s.set("hello".to_string()).unwrap();
+ let c = s.clone();
+ assert_eq!(c.get().map(String::as_str), Some("hello"));
+}
+
+#[test]
+fn get_or_try_init() {
+ let cell: OnceCell<String> = OnceCell::new();
+ assert!(cell.get().is_none());
+
+ let res = std::panic::catch_unwind(|| cell.get_or_try_init(|| -> Result<_, ()> { panic!() }));
+ assert!(res.is_err());
+ assert!(cell.get().is_none());
+
+ assert_eq!(cell.get_or_try_init(|| Err(())), Err(()));
+
+ assert_eq!(cell.get_or_try_init(|| Ok::<_, ()>("hello".to_string())), Ok(&"hello".to_string()));
+ assert_eq!(cell.get(), Some(&"hello".to_string()));
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn wait() {
+ let cell: OnceCell<String> = OnceCell::new();
+ scope(|s| {
+ s.spawn(|| cell.set("hello".to_string()));
+ let greeting = cell.wait();
+ assert_eq!(greeting, "hello")
+ });
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn get_or_init_stress() {
+ let n_threads = if cfg!(miri) { 30 } else { 1_000 };
+ let n_cells = if cfg!(miri) { 30 } else { 1_000 };
+ let cells: Vec<_> = std::iter::repeat_with(|| (Barrier::new(n_threads), OnceCell::new()))
+ .take(n_cells)
+ .collect();
+ scope(|s| {
+ for t in 0..n_threads {
+ let cells = &cells;
+ s.spawn(move || {
+ for (i, (b, s)) in cells.iter().enumerate() {
+ b.wait();
+ let j = if t % 2 == 0 { s.wait() } else { s.get_or_init(|| i) };
+ assert_eq!(*j, i);
+ }
+ });
+ }
+ });
+}
+
+#[test]
+fn from_impl() {
+ assert_eq!(OnceCell::from("value").get(), Some(&"value"));
+ assert_ne!(OnceCell::from("foo").get(), Some(&"bar"));
+}
+
+#[test]
+fn partialeq_impl() {
+ assert!(OnceCell::from("value") == OnceCell::from("value"));
+ assert!(OnceCell::from("foo") != OnceCell::from("bar"));
+
+ assert!(OnceCell::<String>::new() == OnceCell::new());
+ assert!(OnceCell::<String>::new() != OnceCell::from("value".to_owned()));
+}
+
+#[test]
+fn into_inner() {
+ let cell: OnceCell<String> = OnceCell::new();
+ assert_eq!(cell.into_inner(), None);
+ let cell = OnceCell::new();
+ cell.set("hello".to_string()).unwrap();
+ assert_eq!(cell.into_inner(), Some("hello".to_string()));
+}
+
+#[test]
+fn debug_impl() {
+ let cell = OnceCell::new();
+ assert_eq!(format!("{:#?}", cell), "OnceCell(Uninit)");
+ cell.set(vec!["hello", "world"]).unwrap();
+ assert_eq!(
+ format!("{:#?}", cell),
+ r#"OnceCell(
+ [
+ "hello",
+ "world",
+ ],
+)"#
+ );
+}
+
+#[test]
+#[cfg_attr(miri, ignore)] // miri doesn't support processes
+#[cfg(feature = "std")]
+fn reentrant_init() {
+ let examples_dir = {
+ let mut exe = std::env::current_exe().unwrap();
+ exe.pop();
+ exe.pop();
+ exe.push("examples");
+ exe
+ };
+ let bin = examples_dir
+ .join("reentrant_init_deadlocks")
+ .with_extension(std::env::consts::EXE_EXTENSION);
+ let mut guard = Guard { child: std::process::Command::new(bin).spawn().unwrap() };
+ std::thread::sleep(std::time::Duration::from_secs(2));
+ let status = guard.child.try_wait().unwrap();
+ assert!(status.is_none());
+
+ struct Guard {
+ child: std::process::Child,
+ }
+
+ impl Drop for Guard {
+ fn drop(&mut self) {
+ let _ = self.child.kill();
+ }
+ }
+}
+
+#[cfg(not(feature = "std"))]
+#[test]
+#[should_panic(expected = "reentrant init")]
+fn reentrant_init() {
+ let x: OnceCell<Box<i32>> = OnceCell::new();
+ let dangling_ref: Cell<Option<&i32>> = Cell::new(None);
+ x.get_or_init(|| {
+ let r = x.get_or_init(|| Box::new(92));
+ dangling_ref.set(Some(r));
+ Box::new(62)
+ });
+ eprintln!("use after free: {:?}", dangling_ref.get().unwrap());
+}
+
+#[test]
+fn eval_once_macro() {
+ macro_rules! eval_once {
+ (|| -> $ty:ty {
+ $($body:tt)*
+ }) => {{
+ static ONCE_CELL: OnceCell<$ty> = OnceCell::new();
+ fn init() -> $ty {
+ $($body)*
+ }
+ ONCE_CELL.get_or_init(init)
+ }};
+ }
+
+ let fib: &'static Vec<i32> = eval_once! {
+ || -> Vec<i32> {
+ let mut res = vec![1, 1];
+ for i in 0..10 {
+ let next = res[i] + res[i + 1];
+ res.push(next);
+ }
+ res
+ }
+ };
+ assert_eq!(fib[5], 8)
+}
+
+#[test]
+fn once_cell_does_not_leak_partially_constructed_boxes() {
+ let n_tries = if cfg!(miri) { 10 } else { 100 };
+ let n_readers = 10;
+ let n_writers = 3;
+ const MSG: &str = "Hello, World";
+
+ for _ in 0..n_tries {
+ let cell: OnceCell<String> = OnceCell::new();
+ scope(|scope| {
+ for _ in 0..n_readers {
+ scope.spawn(|| loop {
+ if let Some(msg) = cell.get() {
+ assert_eq!(msg, MSG);
+ break;
+ }
+ });
+ }
+ for _ in 0..n_writers {
+ let _ = scope.spawn(|| cell.set(MSG.to_owned()));
+ }
+ });
+ }
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn get_does_not_block() {
+ let cell = OnceCell::new();
+ let barrier = Barrier::new(2);
+ scope(|scope| {
+ scope.spawn(|| {
+ cell.get_or_init(|| {
+ barrier.wait();
+ barrier.wait();
+ "hello".to_string()
+ });
+ });
+ barrier.wait();
+ assert_eq!(cell.get(), None);
+ barrier.wait();
+ });
+ assert_eq!(cell.get(), Some(&"hello".to_string()));
+}
+
+#[test]
+// https://github.com/rust-lang/rust/issues/34761#issuecomment-256320669
+fn arrrrrrrrrrrrrrrrrrrrrr() {
+ let cell = OnceCell::new();
+ {
+ let s = String::new();
+ cell.set(&s).unwrap();
+ }
+}
+
+#[test]
+fn once_cell_is_sync_send() {
+ fn assert_traits<T: Send + Sync>() {}
+ assert_traits::<OnceCell<String>>();
+ assert_traits::<Lazy<String>>();
+}