diff options
Diffstat (limited to 'vendor/once_cell/tests/it/sync_once_cell.rs')
-rw-r--r-- | vendor/once_cell/tests/it/sync_once_cell.rs | 309 |
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>>(); +} |