Changeset 9e3d123

Timestamp:

Jun 16, 2022, 2:39:28 PM (2 years ago)

Author:

caparsons <caparson@…>

Branches:

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

Children:

76a798d

Parents:

e1a9c77

Message:

added atomic_load_n to mcs_spin in attempt at fixing it

File:

• libcfa/src/concurrency/locks.hfa (modified) (1 diff)

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);
-        if(prev != 0p) {
-                prev->next = &n;
-                while(n.locked) Pause();
-        }
+        if(prev == 0p) return;
+        prev->next = &n;
+        while(__atomic_load_n(&n.locked, __ATOMIC_SEQ_CST)) Pause();
 }
 
 static inline void unlock(mcs_spin_lock & l, mcs_spin_node & n) {
         mcs_spin_node * n_ptr = &n;
-        if (!__atomic_compare_exchange_n(&l.queue.tail, &n_ptr, 0p, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ) {
-                while (n.next == 0p) {}
-                n.next->locked = false;
-        }
+        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) {}
+        n.next->locked = false;
 }