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-rw-r--r--third_party/rust/tokio/tests/sync_once_cell.rs274
1 files changed, 274 insertions, 0 deletions
diff --git a/third_party/rust/tokio/tests/sync_once_cell.rs b/third_party/rust/tokio/tests/sync_once_cell.rs
new file mode 100644
index 0000000000..18eaf9382b
--- /dev/null
+++ b/third_party/rust/tokio/tests/sync_once_cell.rs
@@ -0,0 +1,274 @@
+#![warn(rust_2018_idioms)]
+#![cfg(feature = "full")]
+
+use std::mem;
+use std::ops::Drop;
+use std::sync::atomic::{AtomicU32, Ordering};
+use std::time::Duration;
+use tokio::runtime;
+use tokio::sync::{OnceCell, SetError};
+use tokio::time;
+
+async fn func1() -> u32 {
+ 5
+}
+
+async fn func2() -> u32 {
+ time::sleep(Duration::from_millis(1)).await;
+ 10
+}
+
+async fn func_err() -> Result<u32, ()> {
+ Err(())
+}
+
+async fn func_ok() -> Result<u32, ()> {
+ Ok(10)
+}
+
+async fn func_panic() -> u32 {
+ time::sleep(Duration::from_millis(1)).await;
+ panic!();
+}
+
+async fn sleep_and_set() -> u32 {
+ // Simulate sleep by pausing time and waiting for another thread to
+ // resume clock when calling `set`, then finding the cell being initialized
+ // by this call
+ time::sleep(Duration::from_millis(2)).await;
+ 5
+}
+
+async fn advance_time_and_set(cell: &'static OnceCell<u32>, v: u32) -> Result<(), SetError<u32>> {
+ time::advance(Duration::from_millis(1)).await;
+ cell.set(v)
+}
+
+#[test]
+fn get_or_init() {
+ let rt = runtime::Builder::new_current_thread()
+ .enable_time()
+ .start_paused(true)
+ .build()
+ .unwrap();
+
+ static ONCE: OnceCell<u32> = OnceCell::const_new();
+
+ rt.block_on(async {
+ let handle1 = rt.spawn(async { ONCE.get_or_init(func1).await });
+ let handle2 = rt.spawn(async { ONCE.get_or_init(func2).await });
+
+ time::advance(Duration::from_millis(1)).await;
+ time::resume();
+
+ let result1 = handle1.await.unwrap();
+ let result2 = handle2.await.unwrap();
+
+ assert_eq!(*result1, 5);
+ assert_eq!(*result2, 5);
+ });
+}
+
+#[test]
+fn get_or_init_panic() {
+ let rt = runtime::Builder::new_current_thread()
+ .enable_time()
+ .build()
+ .unwrap();
+
+ static ONCE: OnceCell<u32> = OnceCell::const_new();
+
+ rt.block_on(async {
+ time::pause();
+
+ let handle1 = rt.spawn(async { ONCE.get_or_init(func1).await });
+ let handle2 = rt.spawn(async { ONCE.get_or_init(func_panic).await });
+
+ time::advance(Duration::from_millis(1)).await;
+
+ let result1 = handle1.await.unwrap();
+ let result2 = handle2.await.unwrap();
+
+ assert_eq!(*result1, 5);
+ assert_eq!(*result2, 5);
+ });
+}
+
+#[test]
+fn set_and_get() {
+ let rt = runtime::Builder::new_current_thread()
+ .enable_time()
+ .build()
+ .unwrap();
+
+ static ONCE: OnceCell<u32> = OnceCell::const_new();
+
+ rt.block_on(async {
+ let _ = rt.spawn(async { ONCE.set(5) }).await;
+ let value = ONCE.get().unwrap();
+ assert_eq!(*value, 5);
+ });
+}
+
+#[test]
+fn get_uninit() {
+ static ONCE: OnceCell<u32> = OnceCell::const_new();
+ let uninit = ONCE.get();
+ assert!(uninit.is_none());
+}
+
+#[test]
+fn set_twice() {
+ static ONCE: OnceCell<u32> = OnceCell::const_new();
+
+ let first = ONCE.set(5);
+ assert_eq!(first, Ok(()));
+ let second = ONCE.set(6);
+ assert!(second.err().unwrap().is_already_init_err());
+}
+
+#[test]
+fn set_while_initializing() {
+ let rt = runtime::Builder::new_current_thread()
+ .enable_time()
+ .build()
+ .unwrap();
+
+ static ONCE: OnceCell<u32> = OnceCell::const_new();
+
+ rt.block_on(async {
+ time::pause();
+
+ let handle1 = rt.spawn(async { ONCE.get_or_init(sleep_and_set).await });
+ let handle2 = rt.spawn(async { advance_time_and_set(&ONCE, 10).await });
+
+ time::advance(Duration::from_millis(2)).await;
+
+ let result1 = handle1.await.unwrap();
+ let result2 = handle2.await.unwrap();
+
+ assert_eq!(*result1, 5);
+ assert!(result2.err().unwrap().is_initializing_err());
+ });
+}
+
+#[test]
+fn get_or_try_init() {
+ let rt = runtime::Builder::new_current_thread()
+ .enable_time()
+ .start_paused(true)
+ .build()
+ .unwrap();
+
+ static ONCE: OnceCell<u32> = OnceCell::const_new();
+
+ rt.block_on(async {
+ let handle1 = rt.spawn(async { ONCE.get_or_try_init(func_err).await });
+ let handle2 = rt.spawn(async { ONCE.get_or_try_init(func_ok).await });
+
+ time::advance(Duration::from_millis(1)).await;
+ time::resume();
+
+ let result1 = handle1.await.unwrap();
+ assert!(result1.is_err());
+
+ let result2 = handle2.await.unwrap();
+ assert_eq!(*result2.unwrap(), 10);
+ });
+}
+
+#[test]
+fn drop_cell() {
+ static NUM_DROPS: AtomicU32 = AtomicU32::new(0);
+
+ struct Foo {}
+
+ let fooer = Foo {};
+
+ impl Drop for Foo {
+ fn drop(&mut self) {
+ NUM_DROPS.fetch_add(1, Ordering::Release);
+ }
+ }
+
+ {
+ let once_cell = OnceCell::new();
+ let prev = once_cell.set(fooer);
+ assert!(prev.is_ok())
+ }
+ assert!(NUM_DROPS.load(Ordering::Acquire) == 1);
+}
+
+#[test]
+fn drop_cell_new_with() {
+ static NUM_DROPS: AtomicU32 = AtomicU32::new(0);
+
+ struct Foo {}
+
+ let fooer = Foo {};
+
+ impl Drop for Foo {
+ fn drop(&mut self) {
+ NUM_DROPS.fetch_add(1, Ordering::Release);
+ }
+ }
+
+ {
+ let once_cell = OnceCell::new_with(Some(fooer));
+ assert!(once_cell.initialized());
+ }
+ assert!(NUM_DROPS.load(Ordering::Acquire) == 1);
+}
+
+#[test]
+fn drop_into_inner() {
+ static NUM_DROPS: AtomicU32 = AtomicU32::new(0);
+
+ struct Foo {}
+
+ let fooer = Foo {};
+
+ impl Drop for Foo {
+ fn drop(&mut self) {
+ NUM_DROPS.fetch_add(1, Ordering::Release);
+ }
+ }
+
+ let once_cell = OnceCell::new();
+ assert!(once_cell.set(fooer).is_ok());
+ let fooer = once_cell.into_inner();
+ let count = NUM_DROPS.load(Ordering::Acquire);
+ assert!(count == 0);
+ drop(fooer);
+ let count = NUM_DROPS.load(Ordering::Acquire);
+ assert!(count == 1);
+}
+
+#[test]
+fn drop_into_inner_new_with() {
+ static NUM_DROPS: AtomicU32 = AtomicU32::new(0);
+
+ struct Foo {}
+
+ let fooer = Foo {};
+
+ impl Drop for Foo {
+ fn drop(&mut self) {
+ NUM_DROPS.fetch_add(1, Ordering::Release);
+ }
+ }
+
+ let once_cell = OnceCell::new_with(Some(fooer));
+ let fooer = once_cell.into_inner();
+ let count = NUM_DROPS.load(Ordering::Acquire);
+ assert!(count == 0);
+ mem::drop(fooer);
+ let count = NUM_DROPS.load(Ordering::Acquire);
+ assert!(count == 1);
+}
+
+#[test]
+fn from() {
+ let cell = OnceCell::from(2);
+ assert_eq!(*cell.get().unwrap(), 2);
+}
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