Archive for category: Blog

RessourcenmanagementEng

Careful Handling of Resources

December 5, 2016

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The careful handling of resources - may it be, for example, memory, files, or sockets - is a key concern…

POD

Generalized Plain Old Data

December 3, 2016

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Plain Old Data (POD) obeys the C standard layout. Therefore, you can directly apply the fast C functions…

rehashLinux

Buckets, Capacity, and Load Factor

November 29, 2016

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The hash function maps a potentially infinite number of keys on a finite number of buckets. What is the…

hashfunction

Hash Functions

November 27, 2016

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The hash function is responsible for the unordered associative containers' constant access time (best…

windows

Associative Containers – A simple Performance Comparison

November 25, 2016

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Before I take a deeper look insight the interface of the hash tables - officially called unordered associative…

geordneteAssoziativeArrays

Hash Tables

November 24, 2016

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We missed the hash table in C++ for a long time. They promise to have constant access time. C++11 has…

ContainerVersusElement

Type-Traits: Performance Matters

November 21, 2016

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If you look carefully, you see type-traits have a big optimization potential. The type-traits support…

constexpr11

constexpr Functions

November 15, 2016

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constexpr functions are functions that can be executed at compile time. Sounds not so thrilling. But…

userdefinedTypes

constexpr – Variables and Objects

November 13, 2016

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If you declare a variable as constexpr the compiler will evaluate them at compile time. This holds not…

userdefinedLiteralsConstexprResult

Constant Expressions with constexpr

November 11, 2016

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You can define with the keyword constexpr an expression that can be evaluated at compile time. constexpr…

Latest news

Data-Parallel Types – A First ExampleJune 25, 2025 - 4:01 pm
After providing a theoretical introduction to the new C++ 26 feature in my last article, “Data-Parallel Types (SIMD),” I would like to follow up today with a practical example. The following introductory example is from the experimental implementation of the SIMD library. This functionality has been fully adopted in the C++ 26 draft under the […]
Data-Parallel Types (SIMD)June 16, 2025 - 10:24 am
The data-parallel types (SIMD) library provides data-parallel types and operations on them. Today, I want to take a closer look at this. Before diving into the new library, I would like to take a moment to discuss SIMD. SIMD Vectorization refers to the SIMD (Single Instruction, Multiple Data) extensions of a modern processor’s instruction set. […]
Read-copy-update (RCU)June 2, 2025 - 9:54 am
Read-copy-update is strong in multithreading environments where a data structure is read almost exclusively but rarely written. First of all, what is RCU? The excellent Wikipedia page on Read-copy-update provides a good introduction: In computer science, read-copy-update (RCU) is a synchronization mechanism that avoids the use of lock primitives while multiple threads concurrently read and […]
atomic<shared_ptr<>> by Oliver SchädlichMay 19, 2025 - 9:11 am
This blog article is an experiment. A few days ago, I received the following email (translated from German) from Oliver Schädlich (oliver.schaedlich@gmail.com). If, as I hope, this article sparks a discussion, I will be happy to summarize it in my last article. Please send an email to: Rainer.Grimm@ModernesCpp.de. I just read your latest article on […]
Hazard Pointers in C++26May 5, 2025 - 11:12 am
Hazard pointers provide garbage collection in C++ and solve the ABA problem. First of all. What is a hazard pointer? Proposal P2530R3 gives a nice explanation: A hazard pointer is a single-writer multi-reader pointer that can be owned by at most one thread at any time. Only the owner of the hazard pointer can set […]
A Lock-Free Stack: A Hazard Pointer Implementation Explained IIApril 7, 2025 - 11:11 am
In my last post, I started to explain a hazard pointer implementation: A Lock-Free Stack: A Hazard Pointer Implementation Explained I. Today, I will continue to explain the implementation. The Retire List The retire list has the public member functions isInUse, addNode, and deleteUnusedNodes. Additionally, it has the inner class RetireNode, an atomic member of […]