cold errors, benchmark updated, unstable features added

benches/join.rs

@@ -98,20 +98,22 @@ fn join_praetor(b: &mut Bencher) {
 
     let tree = tree::Tree::new(TREE_SIZE, 1u32);
 
-    fn sum(tree: &tree::Tree<u32>, node: usize) -> u32 {
+    fn sum(tree: &tree::Tree<u32>, node: usize, scope: &Scope) -> u32 {
         let node = tree.get(node);
-        Scope::with(|s| {
-            let (l, r) = s.join(
-                || node.left.map(|node| sum(tree, node)).unwrap_or_default(),
-                || node.right.map(|node| sum(tree, node)).unwrap_or_default(),
+        let (l, r) = scope.join(
+            |s| node.left.map(|node| sum(tree, node, s)).unwrap_or_default(),
+            |s| {
+                node.right
+                    .map(|node| sum(tree, node, s))
+                    .unwrap_or_default()
+            },
         );
 
         node.leaf + l + r
-        })
     }
 
     b.iter(move || {
-        let sum = pool.scope(|_| sum(&tree, tree.root().unwrap()));
+        let sum = pool.scope(|s| sum(&tree, tree.root().unwrap(), s));
         // eprintln!("{sum}");
         assert_ne!(sum, 0);
     });

src/lib.rs

@@ -2,6 +2,8 @@
     vec_deque_pop_if,
     unsafe_cell_access,
     debug_closure_helpers,
+    cell_update,
+    cold_path,
     let_chains
 )]
 

src/praetor/mod.rs

@@ -166,6 +166,7 @@ mod job {
         any::Any,
         cell::UnsafeCell,
         fmt::Debug,
+        hint::cold_path,
         marker::PhantomPinned,
         mem::{self, ManuallyDrop, MaybeUninit},
         pin::Pin,
@@ -554,6 +555,7 @@ mod job {
                             let err = unsafe { (&mut *self.err_or_link.get()).error.take() };
 
                             let result: std::thread::Result<T> = if let Some(err) = err {
+                                cold_path();
                                 Err(err)
                             } else {
                                 let val = unsafe {