From 85a239b363591a7f35f66eb8370cabead8545ffa Mon Sep 17 00:00:00 2001
From: Yanqi Lv <lvyanqi.lyq@alibaba-inc.com>
Date: Fri, 19 Jan 2024 23:03:20 +0800
Subject: [PATCH] Change dictGetSafeIterator to dictGetIterator in pubsub
 (#12931)

In #12838, we misuse the safe iterator of the client dict, so we can't
catch the synchronous release of the client if there is a bug.

Since we realize that clients (even subscribers) are released with async
free, we change the safe iterators of the client dict into unsafe
iterators in `pubsub.c`. And I also remove redundant code.
---
 src/pubsub.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/pubsub.c b/src/pubsub.c
index 1a151b96c4..afaf0832fc 100644
--- a/src/pubsub.c
+++ b/src/pubsub.c
@@ -374,9 +374,8 @@ void pubsubShardUnsubscribeAllChannelsInSlot(unsigned int slot) {
     while ((de = dictNext(di)) != NULL) {
         robj *channel = dictGetKey(de);
         dict *clients = dictGetVal(de);
-        if (dictSize(clients) == 0) goto cleanup;
         /* For each client subscribed to the channel, unsubscribe it. */
-        dictIterator *iter = dictGetSafeIterator(clients);
+        dictIterator *iter = dictGetIterator(clients);
         dictEntry *entry;
         while ((entry = dictNext(iter)) != NULL) {
             client *c = dictGetKey(entry);
@@ -390,7 +389,6 @@ void pubsubShardUnsubscribeAllChannelsInSlot(unsigned int slot) {
             }
         }
         dictReleaseIterator(iter);
-cleanup:
         server.shard_channel_count--;
         dictDelete(d, channel);
     }
@@ -529,7 +527,7 @@ int pubsubPublishMessageInternal(robj *channel, robj *message, pubsubtype type)
     if (de) {
         dict *clients = dictGetVal(de);
         dictEntry *entry;
-        dictIterator *iter = dictGetSafeIterator(clients);
+        dictIterator *iter = dictGetIterator(clients);
         while ((entry = dictNext(iter)) != NULL) {
             client *c = dictGetKey(entry);
             addReplyPubsubMessage(c,channel,message,*type.messageBulk);
@@ -557,7 +555,7 @@ int pubsubPublishMessageInternal(robj *channel, robj *message, pubsubtype type)
                                 sdslen(channel->ptr),0)) continue;
 
             dictEntry *entry;
-            dictIterator *iter = dictGetSafeIterator(clients);
+            dictIterator *iter = dictGetIterator(clients);
             while ((entry = dictNext(iter)) != NULL) {
                 client *c = dictGetKey(entry);
                 addReplyPubsubPatMessage(c,pattern,channel,message);