Use mutex to protect costmap reads. (ros-navigation#3877)

* Use mutex to protect costmap reads.
Otherwise costmap can be read during a map update and return 0.

* Revert "Use mutex to protect costmap reads."

This reverts commit e16a44c.

* Lock costmap before running MPPI controller.

* Fix typo.

* Protect against costmap updates in MPP and RotationShim controllers.

---------

Co-authored-by: Leif Terry <leif@peanutrobotics.com>

nav2_mppi_controller/src/controller.cpp

@@ -83,9 +83,12 @@ geometry_msgs::msg::TwistStamped MPPIController::computeVelocityCommands(
   auto start = std::chrono::system_clock::now();
 #endif
 
-  std::lock_guard<std::mutex> lock(*parameters_handler_->getLock());
+  std::lock_guard<std::mutex> param_lock(*parameters_handler_->getLock());
   nav_msgs::msg::Path transformed_plan = path_handler_.transformPath(robot_pose);
 
+  nav2_costmap_2d::Costmap2D * costmap = costmap_ros_->getCostmap();
+  std::unique_lock<nav2_costmap_2d::Costmap2D::mutex_t> costmap_lock(*(costmap->getMutex()));
+
   geometry_msgs::msg::TwistStamped cmd =
     optimizer_.evalControl(robot_pose, robot_speed, transformed_plan, goal_checker);
 

nav2_regulated_pure_pursuit_controller/src/regulated_pure_pursuit_controller.cpp

@@ -157,6 +157,9 @@ geometry_msgs::msg::TwistStamped RegulatedPurePursuitController::computeVelocity
 {
   std::lock_guard<std::mutex> lock_reinit(param_handler_->getMutex());
 
+  nav2_costmap_2d::Costmap2D * costmap = costmap_ros_->getCostmap();
+  std::unique_lock<nav2_costmap_2d::Costmap2D::mutex_t> lock(*(costmap->getMutex()));
+
   // Update for the current goal checker's state
   geometry_msgs::msg::Pose pose_tolerance;
   geometry_msgs::msg::Twist vel_tolerance;

nav2_rotation_shim_controller/src/nav2_rotation_shim_controller.cpp

@@ -140,6 +140,9 @@ geometry_msgs::msg::TwistStamped RotationShimController::computeVelocityCommands
   nav2_core::GoalChecker * goal_checker)
 {
   if (path_updated_) {
+    nav2_costmap_2d::Costmap2D * costmap = costmap_ros_->getCostmap();
+    std::unique_lock<nav2_costmap_2d::Costmap2D::mutex_t> lock(*(costmap->getMutex()));
+
     std::lock_guard<std::mutex> lock_reinit(mutex_);
     try {
       geometry_msgs::msg::Pose sampled_pt_base = transformPoseToBaseFrame(getSampledPathPt());