fix(image_projection_based_fusion): remove mutex (#9862)

refactor: Refactor fusion_node.hpp and fusion_node.cpp for improved code organization and readability

Signed-off-by: Taekjin LEE <taekjin.lee@tier4.jp>

perception/autoware_image_projection_based_fusion/include/autoware/image_projection_based_fusion/fusion_node.hpp

@@ -40,7 +40,6 @@
 
 #include <map>
 #include <memory>
-#include <mutex>
 #include <set>
 #include <string>
 #include <utility>
@@ -127,7 +126,6 @@ class FusionNode : public rclcpp::Node
   // cache for fusion
   int64_t cached_det3d_msg_timestamp_;
   typename Msg3D::SharedPtr cached_det3d_msg_ptr_;
-  std::mutex mutex_cached_msgs_;
 
 protected:
   void setDet2DStatus(std::size_t rois_number);

perception/autoware_image_projection_based_fusion/src/fusion_node.cpp

@@ -280,8 +280,6 @@ void FusionNode<Msg3D, Msg2D, ExportObj>::subCallback(
     }
   }
 
-  std::lock_guard<std::mutex> lock(mutex_cached_msgs_);
-
   // TIMING: reset timer to the timeout time
   auto period = std::chrono::duration_cast<std::chrono::nanoseconds>(
     std::chrono::duration<double, std::milli>(timeout_ms_));
@@ -447,28 +445,16 @@ void FusionNode<Msg3D, Msg2D, ExportObj>::timer_callback()
 
   using std::chrono_literals::operator""ms;
   timer_->cancel();
-  if (mutex_cached_msgs_.try_lock()) {
-    // PROCESS: if timeout, postprocess cached msg
-    if (cached_det3d_msg_ptr_ != nullptr) {
-      stop_watch_ptr_->toc("processing_time", true);
-      exportProcess();
-    }
 
-    // reset flags whether the message is fused or not
-    for (auto & det2d : det2d_list_) {
-      det2d.is_fused = false;
-    }
+  // PROCESS: if timeout, postprocess cached msg
+  if (cached_det3d_msg_ptr_ != nullptr) {
+    stop_watch_ptr_->toc("processing_time", true);
+    exportProcess();
+  }
 
-    mutex_cached_msgs_.unlock();
-  } else {
-    // TIMING: retry the process after 10ms
-    try {
-      std::chrono::nanoseconds period = 10ms;
-      setPeriod(period.count());
-    } catch (rclcpp::exceptions::RCLError & ex) {
-      RCLCPP_WARN_THROTTLE(get_logger(), *get_clock(), 5000, "%s", ex.what());
-    }
-    timer_->reset();
+  // reset flags whether the message is fused or not
+  for (auto & det2d : det2d_list_) {
+    det2d.is_fused = false;
   }
 }