Rico贾若童的博客

Posted by Rico's Nerd Cluster on June 2, 2023

Threading Motivation: Why C++ Concurrency Matters Standardized concurrency arrived with C++11, replacing the ad-hoc C / compiler-specific APIs used before C++98 with a formal memory model. Key l...

Posted by Rico's Nerd Cluster on July 10, 2025

C++ - [Memory Access - 1] Layout

Cache

Memory Access: The Hidden Bottleneck Reference Why Memory Access Matters Even as CPU speeds continue to improve, the cost of fetching data from memory has become a limiting factor. Operating sys...

Posted by Rico's Nerd Cluster on May 27, 2023

C++ Tool Websites

CppInsights, Compiler Explorer, Conan

CppInsights CppInsights does these things: how the standard library objects (like stringstream, vector, etc.) get instantiated how overloaded operators are actually resolved. 1 2 3 4 5 6 7...

Posted by Rico's Nerd Cluster on May 26, 2023

C++ Profiling and Speed Ups

gprof, perf, CMake Release and Debug BoilerPlate, CMake Settings

Gprof GNU gprof provides CPU execution times (not wall time, so sleep is not accounted for) of functions and their subfunctions in percentage. Gprof outputs data in a text-based format, which can ...

Posted by Rico's Nerd Cluster on May 24, 2023

C++ - GTest

GTest For ROS

Concepts Google Test (a.k.a GTest) is an open source unit testing structure. From the official website Test Suite vs Test Case: A test suite contains one or many tests. You should group your t...

Posted by Rico's Nerd Cluster on May 21, 2023

ROS - GDB

GDB for ROS, Core Dump

Introduction GDB is EXTREMELY handy. I used to doing a lot of print statements, but now I use GDB a lot. The reason is simple: I can check multiple things at once without recompiling everytime, es...

Posted by Rico's Nerd Cluster on May 20, 2023

C++ - [Compilation 5] Compilation Speed Ups

Header-only Library Hurts Compilation Time My halo library takes ~2-3min to compile. I have ~20 executables, each executable does target_include_files(70_header_files). Why It’s Slow Every tr...

Posted by Rico's Nerd Cluster on May 13, 2023

C++ - [Compilation 4] Name Mangling

nm

Motivating Example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 void foo(){ const size_t N = 100'000'000; std::vector<int> v(N); // fill v with 1,2,3,... std::...

Posted by Rico's Nerd Cluster on May 7, 2023

C++ - [Compilation 3] Linkage

In C++, Linkage is Either External Or Internal

Linkage In C and C++, linkage determines the accessibility of functions & variables defined in one source file in other different translation units (i.e., different source files). There are t...