std: make `thread::current` available in all `thread_local!` destructors

1 files changed, 32 insertions, 1 deletions

diff --git a/library/std/src/thread/local/tests.rs b/library/std/src/thread/local/tests.rs
index 6abb9b85a2e..9d4f52a0921 100644
--- a/library/std/src/thread/local/tests.rs
+++ b/library/std/src/thread/local/tests.rs
@@ -1,7 +1,7 @@
 use crate::cell::{Cell, UnsafeCell};
 use crate::sync::atomic::{AtomicU8, Ordering};
 use crate::sync::{Arc, Condvar, Mutex};
-use crate::thread::{self, LocalKey};
+use crate::thread::{self, Builder, LocalKey};
 use crate::thread_local;
 
 #[derive(Clone, Default)]
@@ -343,3 +343,34 @@ fn join_orders_after_tls_destructors() {
         jh2.join().unwrap();
     }
 }
+
+// Test that thread::current is still available in TLS destructors.
+#[test]
+fn thread_current_in_dtor() {
+    // Go through one round of TLS destruction first.
+    struct Defer;
+    impl Drop for Defer {
+        fn drop(&mut self) {
+            RETRIEVE.with(|_| {});
+        }
+    }
+
+    struct RetrieveName;
+    impl Drop for RetrieveName {
+        fn drop(&mut self) {
+            *NAME.lock().unwrap() = Some(thread::current().name().unwrap().to_owned());
+        }
+    }
+
+    static NAME: Mutex<Option<String>> = Mutex::new(None);
+
+    thread_local! {
+        static DEFER: Defer = const { Defer };
+        static RETRIEVE: RetrieveName = const { RetrieveName };
+    }
+
+    Builder::new().name("test".to_owned()).spawn(|| DEFER.with(|_| {})).unwrap().join().unwrap();
+    let name = NAME.lock().unwrap();
+    let name = name.as_ref().unwrap();
+    assert_eq!(name, "test");
+}