Fix __atomic_compare_exchange_n() atomics (#14085)

* proper use for atomic_compare_exchange()

* diskspace plugin is multi-threaded but it uses single threaded dictionaries

1 files changed, 5 insertions, 4 deletions

diff --git a/libnetdata/string/string.c b/libnetdata/string/string.c
index a3f74b4ef4..d2db8aab43 100644
--- a/libnetdata/string/string.c
+++ b/libnetdata/string/string.c
@@ -71,11 +71,12 @@ void string_statistics(size_t *inserts, size_t *deletes, size_t *searches, size_
 
 static inline bool string_entry_check_and_acquire(STRING *se) {
     REFCOUNT expected, desired, count = 0;
+
+    expected = __atomic_load_n(&se->refcount, __ATOMIC_SEQ_CST);
+
     do {
         count++;
 
-        expected = __atomic_load_n(&se->refcount, __ATOMIC_SEQ_CST);
-
         if(expected <= 0) {
             // We cannot use this.
             // The reference counter reached value zero,
@@ -85,8 +86,8 @@ static inline bool string_entry_check_and_acquire(STRING *se) {
         }
 
         desired = expected + 1;
-    }
-    while(!__atomic_compare_exchange_n(&se->refcount, &expected, desired, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST));
+
+    } while(!__atomic_compare_exchange_n(&se->refcount, &expected, desired, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST));
 
     string_internal_stats_add(spins, count - 1);