From 027ad5058185510c2b2df715614babbdcdd68aab Mon Sep 17 00:00:00 2001
From: John Sully <john@csquare.ca>
Date: Tue, 17 May 2022 03:34:37 +0000
Subject: [PATCH] Dictionary use correct acquire/release semantics

---
 src/db.cpp   | 5 +++--
 src/dict.cpp | 4 +++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/db.cpp b/src/db.cpp
index 5b67a4198..0ad3df99f 100644
--- a/src/db.cpp
+++ b/src/db.cpp
@@ -3263,10 +3263,11 @@ bool redisDbPersistentData::prefetchKeysAsync(client *c, parsed_command &command
                     dictEntry **table;
                     __atomic_load(&c->db->m_pdict->ht[iht].table, &table, __ATOMIC_RELAXED);
                     if (table != nullptr) {
-                        dictEntry *de = table[hT];
+                        dictEntry *de;
+                        __atomic_load(&table[hT], &de, __ATOMIC_ACQUIRE);
                         while (de != nullptr) {
                             _mm_prefetch(dictGetKey(de), _MM_HINT_T2);
-                            de = de->next;
+                            __atomic_load(&de->next, &de, __ATOMIC_ACQUIRE);
                         }
                     }
                     if (!dictIsRehashing(c->db->m_pdict))
diff --git a/src/dict.cpp b/src/dict.cpp
index e8de025f7..b29c0e24b 100644
--- a/src/dict.cpp
+++ b/src/dict.cpp
@@ -403,7 +403,7 @@ int dictRehash(dict *d, int n) {
 
 dictAsyncRehashCtl::dictAsyncRehashCtl(struct dict *d, dictAsyncRehashCtl *next) : dict(d), next(next) {
     queue.reserve(c_targetQueueSize);
-    __atomic_fetch_add(&d->refcount, 1, __ATOMIC_RELEASE);
+    __atomic_fetch_add(&d->refcount, 1, __ATOMIC_ACQ_REL);
     this->rehashIdxBase = d->rehashidx;
 }
 
@@ -810,6 +810,8 @@ int _dictClear(dict *d, dictht *ht, void(callback)(void *)) {
         if (callback && (i & 65535) == 0) callback(d->privdata);
 
         if ((he = ht->table[i]) == NULL) continue;
+        dictEntry *deNull = nullptr;
+        __atomic_store(&ht->table[i], &deNull, __ATOMIC_RELEASE);
         while(he) {
             nextHe = he->next;
             if (d->asyncdata && (ssize_t)i < d->rehashidx) {