branch-3.0: [fix](runtime_profile) fix race condition in to_thrift #4…

…5047 (#45098) Cherry-picked from #45047 Co-authored-by: Kaijie Chen <[email protected]>
apache · Dec 6, 2024 · 3f3a9f4 · 3f3a9f4
1 parent d1c20c4
commit 3f3a9f4
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/be/src/util/runtime_profile.cpp b/be/src/util/runtime_profile.cpp
@@ -577,8 +577,6 @@ void RuntimeProfile::to_thrift(TRuntimeProfileTree* tree) {
 }
 
 void RuntimeProfile::to_thrift(std::vector<TRuntimeProfileNode>* nodes) {
-    nodes->reserve(nodes->size() + _children.size());
-
     int index = nodes->size();
     nodes->push_back(TRuntimeProfileNode());
     TRuntimeProfileNode& node = (*nodes)[index];
@@ -605,10 +603,13 @@ void RuntimeProfile::to_thrift(std::vector<TRuntimeProfileNode>* nodes) {
 
     ChildVector children;
     {
+        // _children may be modified during to_thrift(),
+        // so we have to lock and copy _children to avoid race condition
         std::lock_guard<std::mutex> l(_children_lock);
         children = _children;
     }
     node.num_children = children.size();
+    nodes->reserve(nodes->size() + children.size());
 
     for (int i = 0; i < children.size(); ++i) {
         int child_idx = nodes->size();