Why is there a segmentation fault here?

[SylarAnh]

Stack trace (most recent call last): #21 Object "/usr/lib/x86_64-linux-gnu/ld-2.31.so", at 0xffffffffffffffff, in #20 Object "/home/jcwang/code/ws_di-lui-sam/src/di_lui_sam/cmake-build-debug/devel/lib/multi_proxy/multi_proxy_subMapFusion", at 0x555555600ead, in start #19 Source "../csu/libc-start.c", line 308, in libc_start_main [0x7ffff45e6082] #18 Source "/home/jcwang/code/ws_di-lui-sam/src/di_lui_sam/src/subMapFusion.cpp", line 2235, in main [0x555555601305] 2232: std::thread OptThread(&SubMapFusion::globalOptimizationThread, &SubMapF); 2233: std::thread pubLoopThread(&SubMapFusion::publishSCWithCloudThread, &SubMapF); 2234: >2235: ros::spin(); 2236: 2237: pubDesOtherThread.join(); 2238: pubMapThread.join(); #17 Object "/opt/ros/noetic/lib/libroscpp.so", at 0x7ffff7f2a21e, in ros::spin() #16 Object "/opt/ros/noetic/lib/libroscpp.so", at 0x7ffff7f41fce, in ros::SingleThreadedSpinner::spin(ros::CallbackQueue*) #15 Object "/opt/ros/noetic/lib/libroscpp.so", at 0x7ffff7eee882, in ros::CallbackQueue::callAvailable(ros::WallDuration) #14 Object "/opt/ros/noetic/lib/libroscpp.so", at 0x7ffff7eed171, in ros::CallbackQueue::callOneCB(ros::CallbackQueue::TLS*) #13 Object "/opt/ros/noetic/lib/libroscpp.so", at 0x7ffff7f3f138, in ros::SubscriptionQueue::call() #12 Source "/opt/ros/noetic/include/ros/subscription_callback_helper.h", line 144, in call [0x5555556fe2ca] 141: virtual void call(SubscriptionCallbackHelperCallParams& params) 142: { 143: Event event(params.event, create); > 144: callback(ParameterAdapter<P>::getParameter(event)); 145: } 146: 147: virtual const std::type_info& getTypeInfo() #11 Source "/usr/include/boost/function/function_template.hpp", line 763, in operator() [0x555555702548] 760: if (this->empty()) 761: boost::throw_exception(bad_function_call()); 762: > 763: return get_vtable()->invoker 764: (this->functor BOOST_FUNCTION_COMMA BOOST_FUNCTION_ARGS); 765: } #10 Source "/usr/include/boost/function/function_template.hpp", line 158, in invoke [0x5555556b57eb] 155: f = reinterpret_cast<FunctionObj*>(function_obj_ptr.data); 156: else 157: f = reinterpret_cast<FunctionObj*>(function_obj_ptr.members.obj_ptr); > 158: BOOST_FUNCTION_RETURN((f)(BOOST_FUNCTION_ARGS)); 159: } 160: }; #9 Source "/usr/include/boost/function/function_template.hpp", line 763, in operator() [0x5555556c1db5] 760: if (this->empty()) 761: boost::throw_exception(bad_function_call()); 762: > 763: return get_vtable()->invoker 764: (this->functor BOOST_FUNCTION_COMMA BOOST_FUNCTION_ARGS); 765: } #8 Source "/usr/include/boost/function/function_template.hpp", line 158, in invoke [0x555555696649] 155: f = reinterpret_cast<FunctionObj>(function_obj_ptr.data); 156: else 157: f = reinterpret_cast<FunctionObj*>(function_obj_ptr.members.obj_ptr); > 158: BOOST_FUNCTION_RETURN((*f)(BOOST_FUNCTION_ARGS)); 159: } 160: }; #7 Source "/usr/include/boost/bind/bind.hpp", line 1306, in operator()<const boost::shared_ptr<const sensor_msgs::PointCloud2<std::allocator > >&> [0x5555556a70ac] 1303: template<class A1> result_type operator()( A1 && a1 ) 1304: { 1305: rrlist1< A1 > a( a1 ); >1306: return l_( type<result_type>(), f_, a, 0 ); 1307: } 1308: 1309: template<class A1> result_type operator()( A1 && a1 ) const #6 Source "/usr/include/boost/bind/bind.hpp", line 319, in operator()<boost::mfi::mf1<void, SubMapFusion, const boost::shared_ptr<const sensor_msgs::PointCloud2<std::allocator > >&>, boost::bi::rrlist1<const boost::shared_ptr<const sensor_msgs::PointCloud2<std::allocator > >&> > [0x5555556b5515] 317: template<class F, class A> void operator()(type, F & f, A & a, int) 318: { > 319: unwrapper<F>::unwrap(f, 0)(a[base_type::a1_], a[base_type::a2_]); 320: } 321: 322: template<class F, class A> void operator()(type, F const & f, A & a, int) const #5 Source "/usr/include/boost/bind/mem_fn_template.hpp", line 165, in operator() [0x5555556c1a47] 163: R operator()(T * p, A1 a1) const 164: { > 165: BOOST_MEM_FN_RETURN (p->f_)(a1); 166: } 167: 168: template<class U> R operator()(U & u, A1 a1) const #4 Source "/home/jcwang/code/ws_di-lui-sam/src/di_lui_sam/src/subMapFusion.cpp", line 681, in laserCloudInfoHandler [0x55555561e8f4] 679: isKeyframe(context_info); 680: buildFrameList(context_info); > 681: buildSubmap(context_info); 682: } 683: // std::cout << "laser: finished! " << std::endl; 684: } #3 Source "/home/jcwang/code/ws_di-lui-sam/src/di_lui_sam/src/subMapFusion.cpp", line 1109, in buildSubmap [0x555555623a08] 1106: _downsize_filtermap.setInputCloud(cloud_in_ego_odom); 1107: _downsize_filtermap.filter(_cloud_temp); 1108: >1109: buildiKDTree(_cloud_temp);//////TODO：这里有问题，会重复释放内存 1110: mtx_map.lock(); 1111: *_lidarmap_current += *_cloud_temp; 1112: _cloud_temp->clear(); #2 Source "/home/jcwang/code/ws_di-lui-sam/src/di_lui_sam/src/subMapFusion.cpp", line 1164, in buildiKDTree [0x555555624060] 1161: } 1162: 1163: double st_time = omp_get_wtime(); >1164: ikdtree.Add_Points(PointToAdd, true); 1165: double kdtree_incremental_time = omp_get_wtime() - st_time; 1166: } #1 Source "/home/jcwang/code/ws_di-lui-sam/src/di_lui_sam/third_parties/ikd-Tree/ikd_Tree.cpp", line 501, in Add_Points [0x7ffff72eff4d] 498: mid_point.y = Box_of_Point.vertex_min[1] + (Box_of_Point.vertex_max[1] - Box_of_Point.vertex_min[1]) / 2.0; 499: mid_point.z = Box_of_Point.vertex_min[2] + (Box_of_Point.vertex_max[2] - Box_of_Point.vertex_min[2]) / 2.0; 500: PointVector().swap(Downsample_Storage); > 501: Search_by_range(Root_Node, Box_of_Point, Downsample_Storage); 502: min_dist = calc_dist(PointToAdd[i], mid_point); 503: downsample_result = PointToAdd[i]; 504: for (int index = 0; index < Downsample_Storage.size(); index++) #0 Source "/home/jcwang/code/ws_di-lui-sam/src/di_lui_sam/third_parties/ikd-Tree/ikd_Tree.cpp", line 1268, in Search_by_range [0x7ffff72ecce4] 1265: if (!root->point_deleted) 1266: Storage.push_back(root->point); 1267: } >1268: if ((Rebuild_Ptr == nullptr) || root->left_son_ptr != *Rebuild_Ptr) 1269: { 1270: Search_by_range(root->left_son_ptr, boxpoint, Storage); 1271: } Segmentation fault (Address not mapped to object [(nil)])

[FPSE12]

I have the same issue, I got a "segment fault" when I use the "Add_Points" function.

[ludovicoruga]

I am also experiencing the same issue:

Any support would be greatly appreciated!

[ludovicoruga]

I noticed that if I set the value if 'Minimal_Unbalanced_Tree_Size' to INIFINITY in ikd_tree.h, the segmentation fault error stops happening. I think this could indicate an issue with the re-building process in the second thread. This is not a viable solution since when the tree size increases, the computation time increases exponentially, but could give an idea on where to look for to fix the issue.

I hope this can be useful!

[ning-zelin]

rebuild thread: write Rebuild_Ptr: add points thread: read Rebuild_Ptr: This variable was read and written without mutex, leading to a segmentation fault. This is merely my initial hypothesis and has yet to be confirmed.

[XYudong]

Experiencing the same issue here. Having the same hypothesis as what @ning-zelin mentioned. A temporary workaround could be:

1. comment out the code creating the rebuild_thread to disable multi-threading for rebuild;
2. adjust Rebuild() method to always use the plain rebuild pipeline;

which seems work for me currently.

[supersupercoconut]

Experiencing the same issue here. Having the same hypothesis as what @ning-zelin mentioned. A temporary workaround could be:

1. comment out the code creating the rebuild_thread to disable multi-threading for rebuild;
2. adjust Rebuild() method to always use the plain rebuild pipeline;

which seems work for me currently. Thanks!! I commeted out the pthread_create( &rebuild_thread, NULL, multi_thread_ptr, ( void * ) this ); Its works now !!