Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/library/std/src/sys_common/thread_info.rs b/library/std/src/sys_common/thread_info.rs
new file mode 100644
index 000000000..38c9e5000
--- /dev/null
+++ b/library/std/src/sys_common/thread_info.rs
@@ -0,0 +1,47 @@
+#![allow(dead_code)] // stack_guard isn't used right now on all platforms
+#![allow(unused_unsafe)] // thread_local with `const {}` triggers this liny
+
+use crate::cell::RefCell;
+use crate::sys::thread::guard::Guard;
+use crate::thread::Thread;
+
+struct ThreadInfo {
+    stack_guard: Option<Guard>,
+    thread: Thread,
+}
+
+thread_local! { static THREAD_INFO: RefCell<Option<ThreadInfo>> = const { RefCell::new(None) } }
+
+impl ThreadInfo {
+    fn with<R, F>(f: F) -> Option<R>
+    where
+        F: FnOnce(&mut ThreadInfo) -> R,
+    {
+        THREAD_INFO
+            .try_with(move |thread_info| {
+                let mut thread_info = thread_info.borrow_mut();
+                let thread_info = thread_info.get_or_insert_with(|| ThreadInfo {
+                    stack_guard: None,
+                    thread: Thread::new(None),
+                });
+                f(thread_info)
+            })
+            .ok()
+    }
+}
+
+pub fn current_thread() -> Option<Thread> {
+    ThreadInfo::with(|info| info.thread.clone())
+}
+
+pub fn stack_guard() -> Option<Guard> {
+    ThreadInfo::with(|info| info.stack_guard.clone()).and_then(|o| o)
+}
+
+pub fn set(stack_guard: Option<Guard>, thread: Thread) {
+    THREAD_INFO.with(move |thread_info| {
+        let mut thread_info = thread_info.borrow_mut();
+        rtassert!(thread_info.is_none());
+        *thread_info = Some(ThreadInfo { stack_guard, thread });
+    });
+}