From 7bd0edb9700409fb8709f49d3a866bd4d790655a Mon Sep 17 00:00:00 2001
From: John Sully <john@csquare.ca>
Date: Thu, 9 Jul 2020 22:29:27 +0000
Subject: [PATCH] Fix race in db iterators in scan

Former-commit-id: a6444870660c0d3f52cd7b1dc0b80223f0d58e70
---
 src/dict.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/dict.cpp b/src/dict.cpp
index 0e8827165..ef7365fdb 100644
--- a/src/dict.cpp
+++ b/src/dict.cpp
@@ -952,7 +952,7 @@ unsigned long dictScan(dict *d,
 
     /* Having a safe iterator means no rehashing can happen, see _dictRehashStep.
      * This is needed in case the scan callback tries to do dictFind or alike. */
-    d->iterators++;
+    __atomic_fetch_add(&d->iterators, 1, __ATOMIC_SEQ_CST);
 
     if (!dictIsRehashing(d)) {
         t0 = &(d->ht[0]);
@@ -1021,7 +1021,7 @@ unsigned long dictScan(dict *d,
     }
 
     /* undo the ++ at the top */
-    d->iterators--;
+    __atomic_fetch_sub(&d->iterators, 1, __ATOMIC_SEQ_CST);
 
     return v;
 }