From 4facac023f936c4840eff1ae7a9f486751aba13e Mon Sep 17 00:00:00 2001
From: fangfengbin <869218239a@zju.edu.cn>
Date: Tue, 16 Jun 2020 21:00:37 +0800
Subject: [PATCH] Fix heap-use-after-free bug of gcs pub sub testcase (#8968)

---
 src/ray/gcs/pubsub/test/gcs_pub_sub_test.cc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/ray/gcs/pubsub/test/gcs_pub_sub_test.cc b/src/ray/gcs/pubsub/test/gcs_pub_sub_test.cc
index d0aa3943e..46a9c01bd 100644
--- a/src/ray/gcs/pubsub/test/gcs_pub_sub_test.cc
+++ b/src/ray/gcs/pubsub/test/gcs_pub_sub_test.cc
@@ -45,9 +45,13 @@ class GcsPubSubTest : public ::testing::Test {
     pub_sub_.reset();
     client_->Disconnect();
     io_service_.stop();
-    client_.reset();
     thread_io_service_->join();
     thread_io_service_.reset();
+
+    // Note: If we immediately reset client_ after io_service_ stop, because client_ still
+    // has thread executing logic, such as unsubscribe's callback, the problem of heap
+    // used after free will occur.
+    client_.reset();
   }
 
   void Subscribe(const std::string &channel, const std::string &id,