From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- library/core/tests/lazy.rs | 138 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 library/core/tests/lazy.rs (limited to 'library/core/tests/lazy.rs') diff --git a/library/core/tests/lazy.rs b/library/core/tests/lazy.rs new file mode 100644 index 000000000..70fcc6d2d --- /dev/null +++ b/library/core/tests/lazy.rs @@ -0,0 +1,138 @@ +use core::{ + cell::{Cell, LazyCell, OnceCell}, + sync::atomic::{AtomicUsize, Ordering::SeqCst}, +}; + +#[test] +fn once_cell() { + let c = OnceCell::new(); + assert!(c.get().is_none()); + 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_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_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(); + x.get_or_init(|| Dropper); + assert_eq!(DROP_CNT.load(SeqCst), 0); + drop(x); + assert_eq!(DROP_CNT.load(SeqCst), 1); +} + +#[test] +fn unsync_once_cell_drop_empty() { + let x = OnceCell::<&'static str>::new(); + drop(x); +} + +#[test] +const fn once_cell_const() { + let _once_cell: OnceCell = OnceCell::new(); + let _once_cell: OnceCell = OnceCell::from(32); +} + +#[test] +fn clone() { + let s = OnceCell::new(); + let c = s.clone(); + assert!(c.get().is_none()); + + s.set("hello").unwrap(); + let c = s.clone(); + assert_eq!(c.get().map(|c| *c), Some("hello")); +} + +#[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::<&'static str>::new() == OnceCell::new()); + assert!(OnceCell::<&'static str>::new() != OnceCell::from("value")); +} + +#[test] +fn into_inner() { + let cell: OnceCell<&'static str> = OnceCell::new(); + assert_eq!(cell.into_inner(), None); + let cell = OnceCell::new(); + cell.set("hello").unwrap(); + assert_eq!(cell.into_inner(), Some("hello")); +} + +#[test] +fn lazy_new() { + let called = Cell::new(0); + let x = LazyCell::new(|| { + called.set(called.get() + 1); + 92 + }); + + assert_eq!(called.get(), 0); + + let y = *x - 30; + assert_eq!(y, 62); + assert_eq!(called.get(), 1); + + let y = *x - 30; + assert_eq!(y, 62); + assert_eq!(called.get(), 1); +} + +#[test] +fn aliasing_in_get() { + let x = OnceCell::new(); + x.set(42).unwrap(); + let at_x = x.get().unwrap(); // --- (shared) borrow of inner `Option` --+ + let _ = x.set(27); // <-- temporary (unique) borrow of inner `Option` | + println!("{at_x}"); // <------- up until here ---------------------------+ +} + +#[test] +#[should_panic(expected = "reentrant init")] +fn reentrant_init() { + let x: OnceCell> = OnceCell::new(); + let dangling_ref: Cell> = 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 dropck() { + let cell = OnceCell::new(); + { + let s = String::new(); + cell.set(&s).unwrap(); + } +} -- cgit v1.2.3