1 files changed, 31 insertions, 0 deletions
diff --git a/src/runtime/thread_id.rs b/src/runtime/thread_id.rs
new file mode 100644
index 0000000..ef39289
--- /dev/null
+++ b/src/runtime/thread_id.rs
@@ -0,0 +1,31 @@
+use std::num::NonZeroU64;
+
+#[derive(Eq, PartialEq, Clone, Copy, Hash, Debug)]
+pub(crate) struct ThreadId(NonZeroU64);
+
+impl ThreadId {
+    pub(crate) fn next() -> Self {
+        use crate::loom::sync::atomic::{Ordering::Relaxed, StaticAtomicU64};
+
+        static NEXT_ID: StaticAtomicU64 = StaticAtomicU64::new(0);
+
+        let mut last = NEXT_ID.load(Relaxed);
+        loop {
+            let id = match last.checked_add(1) {
+                Some(id) => id,
+                None => exhausted(),
+            };
+
+            match NEXT_ID.compare_exchange_weak(last, id, Relaxed, Relaxed) {
+                Ok(_) => return ThreadId(NonZeroU64::new(id).unwrap()),
+                Err(id) => last = id,
+            }
+        }
+    }
+}
+
+#[cold]
+#[allow(dead_code)]
+fn exhausted() -> ! {
+    panic!("failed to generate unique thread ID: bitspace exhausted")
+}