Changeset 76a798d

Timestamp:

Jun 16, 2022, 2:47:50 PM (2 years ago)

Author:

caparsons <caparson@…>

Branches:

ADT, ast-experimental, master, pthread-emulation, qualifiedEnum

Children:

9e23b446, df932552

Parents:

9e3d123

Message:

hopefully fixed mcs spin lock

File:

• libcfa/src/concurrency/locks.hfa (modified) (2 diffs)

libcfa/src/concurrency/locks.hfa

@@ -126 +126 @@
 static inline void lock(mcs_spin_lock & l, mcs_spin_node & n) {
         mcs_spin_node * prev = __atomic_exchange_n(&l.queue.tail, &n, __ATOMIC_SEQ_CST);
+        n.locked = true;
         if(prev == 0p) return;
         prev->next = &n;
-        while(__atomic_load_n(&n.locked, __ATOMIC_SEQ_CST)) Pause();
+        while(__atomic_load_n(&n.locked, __ATOMIC_RELAXED)) Pause();
 }
 
@@ -134 +135 @@
         mcs_spin_node * n_ptr = &n;
         if (__atomic_compare_exchange_n(&l.queue.tail, &n_ptr, 0p, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) return;
-        while (__atomic_load_n(&n.next, __ATOMIC_SEQ_CST) == 0p) {}
+        while (__atomic_load_n(&n.next, __ATOMIC_RELAXED) == 0p) {}
         n.next->locked = false;
 }