From 211add4fd3b3fb846aeee975dbc6a3158996d839 Mon Sep 17 00:00:00 2001
From: Kai-Tao Xie <kaitaoxie@qq.com>
Date: Mon, 16 Aug 2021 20:18:57 +0800
Subject: [PATCH] fix data race: addPlugin() and resizeMap() can be executed
 concurrently

---
 nav2_costmap_2d/include/nav2_costmap_2d/layered_costmap.hpp | 6 ++----
 nav2_costmap_2d/src/layered_costmap.cpp                     | 6 ++++++
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/nav2_costmap_2d/include/nav2_costmap_2d/layered_costmap.hpp b/nav2_costmap_2d/include/nav2_costmap_2d/layered_costmap.hpp
index a0602b6865a..ddf64ffbdc1 100644
--- a/nav2_costmap_2d/include/nav2_costmap_2d/layered_costmap.hpp
+++ b/nav2_costmap_2d/include/nav2_costmap_2d/layered_costmap.hpp
@@ -146,10 +146,8 @@ class LayeredCostmap
   /**
    * @brief Add a new plugin to the plugins vector to process
    */
-  void addPlugin(std::shared_ptr<Layer> plugin)
-  {
-    plugins_.push_back(plugin);
-  }
+  void addPlugin(std::shared_ptr<Layer> plugin);
+
 
   /**
    * @brief Add a new costmap filter plugin to the filters vector to process
diff --git a/nav2_costmap_2d/src/layered_costmap.cpp b/nav2_costmap_2d/src/layered_costmap.cpp
index e31ebe1414c..bd3d37cd31e 100644
--- a/nav2_costmap_2d/src/layered_costmap.cpp
+++ b/nav2_costmap_2d/src/layered_costmap.cpp
@@ -89,6 +89,12 @@ LayeredCostmap::~LayeredCostmap()
   }
 }
 
+void LayeredCostmap::addPlugin(std::shared_ptr<Layer> plugin)
+{
+  std::unique_lock<Costmap2D::mutex_t> lock(*(combined_costmap_.getMutex()));
+  plugins_.push_back(plugin);
+}
+
 void LayeredCostmap::resizeMap(
   unsigned int size_x, unsigned int size_y, double resolution,
   double origin_x,