From c2a62b717a0de9011912dbcbf019287d7394795c Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 16 Jan 2026 06:51:22 +0000
Subject: [PATCH 1/3] Initial plan


From 5b85a1e4500a965ad87ec5ebc58fa43e8d7d5e2d Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 16 Jan 2026 06:55:37 +0000
Subject: [PATCH 2/3] Fix concurrent issue in MariaModule by adding mutex
 synchronization

- Added mutable std::mutex groups_mutex_ to MariaModule class
- Updated ResizeGroups() and SetGroup() to protect vector modification with mutex
- Updated ExtThdStart() to use mutex and check for nullptr before dereferencing
- Updated ExtThdEnd() to use mutex and check for nullptr before dereferencing
- Updated Process() to use mutex and check for nullptr before dereferencing
- Updated HasTask() to use mutex and check for nullptr before dereferencing

Co-authored-by: githubzilla <10080336+githubzilla@users.noreply.github.com>
---
 sql/threadpool_generic.cc | 45 ++++++++++++++++++++++++++++++---------
 sql/threadpool_generic.h  | 13 +++++++++--
 2 files changed, 46 insertions(+), 12 deletions(-)

diff --git a/sql/threadpool_generic.cc b/sql/threadpool_generic.cc
index f791ed03d5b..e0d1707269a 100644
--- a/sql/threadpool_generic.cc
+++ b/sql/threadpool_generic.cc
@@ -2539,22 +2539,38 @@ bool thread_group_t::HasActiveWorker() const
 #ifdef ELOQ_MODULE_ENABLED
 void MariaModule::ExtThdStart(int thd_id)
 {
-  if (thd_id < 0 || (size_t) thd_id >= groups_.size())
+  thread_group_t *group = nullptr;
+  {
+    std::lock_guard<std::mutex> lk(groups_mutex_);
+    if (thd_id >= 0 && (size_t)thd_id < groups_.size()) {
+      group = groups_[thd_id];
+    }
+  }
+
+  if (group == nullptr)
   {
     return;
   }
 
   SetIsSqlThd(false);
-  groups_[thd_id]->ext_worker_active_.store(true, std::memory_order_relaxed);
+  group->ext_worker_active_.store(true, std::memory_order_relaxed);
 }
 
 void MariaModule::ExtThdEnd(int thd_id)
 {
-  if (thd_id < 0 || (size_t) thd_id >= groups_.size())
+  thread_group_t *group = nullptr;
+  {
+    std::lock_guard<std::mutex> lk(groups_mutex_);
+    if (thd_id >= 0 && (size_t)thd_id < groups_.size()) {
+      group = groups_[thd_id];
+    }
+  }
+
+  if (group == nullptr)
   {
     return;
   }
-  thread_group_t *group = groups_[thd_id];
+
   group->ext_worker_active_.store(false, std::memory_order_relaxed);
 
   mysql_mutex_lock(&group->mutex);
@@ -2575,13 +2591,15 @@ void MariaModule::ExtThdEnd(int thd_id)
 
 void MariaModule::Process(int thd_id)
 {
-  if (thd_id < 0 || (size_t) thd_id >= groups_.size())
+  thread_group_t *group = nullptr;
   {
-    return;
+    std::lock_guard<std::mutex> lk(groups_mutex_);
+    if (thd_id >= 0 && (size_t)thd_id < groups_.size()) {
+      group = groups_[thd_id];
+    }
   }
 
-  thread_group_t *group = groups_[thd_id];
-  if (group->shutdown.load(std::memory_order_relaxed))
+  if (group == nullptr || group->shutdown.load(std::memory_order_relaxed))
   {
     return;
   }
@@ -2673,12 +2691,19 @@ void MariaModule::Process(int thd_id)
 
 bool MariaModule::HasTask(int thd_id) const
 {
-  if (thd_id < 0 || (size_t) thd_id >= groups_.size())
+  thread_group_t *group = nullptr;
+  {
+    std::lock_guard<std::mutex> lk(groups_mutex_);
+    if (thd_id >= 0 && (size_t)thd_id < groups_.size()) {
+      group = groups_[thd_id];
+    }
+  }
+
+  if (group == nullptr)
   {
     return false;
   }
 
-  thread_group_t *group= groups_[thd_id];
   CoroutineInfo *coro_info= group->coroutine_info_.get();
   return !coro_info->req_queue_.IsEmpty() ||
          !coro_info->resume_queue_.IsEmpty() ||
diff --git a/sql/threadpool_generic.h b/sql/threadpool_generic.h
index 5502540dbb7..ee855d4cd0b 100644
--- a/sql/threadpool_generic.h
+++ b/sql/threadpool_generic.h
@@ -251,11 +251,20 @@ class MariaModule : public eloq::EloqModule
   void Process(int thd_id) override;
   bool HasTask(int thd_id) const override;
 
-  void ResizeGroups(size_t size) { groups_.resize(size, nullptr); }
-  void SetGroup(size_t gid, thread_group_t *group) { groups_[gid]= group; }
+  void ResizeGroups(size_t size) 
+  { 
+    std::lock_guard<std::mutex> lk(groups_mutex_);
+    groups_.resize(size, nullptr); 
+  }
+  void SetGroup(size_t gid, thread_group_t *group) 
+  { 
+    std::lock_guard<std::mutex> lk(groups_mutex_);
+    groups_[gid]= group; 
+  }
 
 private:
   std::vector<thread_group_t *> groups_;
+  mutable std::mutex groups_mutex_;
 };
 #endif
 

From 0545d763df823e538bfd6181dd54000a72d79819 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 16 Jan 2026 06:57:46 +0000
Subject: [PATCH 3/3] Add bounds checking to SetGroup method

Added defensive bounds checking in SetGroup() to prevent potential out-of-bounds access.
Fixed code style to use space around assignment operator.

Co-authored-by: githubzilla <10080336+githubzilla@users.noreply.github.com>
---
 sql/threadpool_generic.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sql/threadpool_generic.h b/sql/threadpool_generic.h
index ee855d4cd0b..5c553d569a9 100644
--- a/sql/threadpool_generic.h
+++ b/sql/threadpool_generic.h
@@ -259,7 +259,9 @@ class MariaModule : public eloq::EloqModule
   void SetGroup(size_t gid, thread_group_t *group) 
   { 
     std::lock_guard<std::mutex> lk(groups_mutex_);
-    groups_[gid]= group; 
+    if (gid < groups_.size()) {
+      groups_[gid] = group; 
+    }
   }
 
 private: