Archive for category: Embedded

rehashLinux

Buckets, Capacity, and Load Factor

November 29, 2016

/

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

/

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

windows

Associative Containers – A simple Performance Comparison

November 25, 2016

/

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

geordneteAssoziativeArrays

Hash Tables

November 24, 2016

/

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

/

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

constexpr11

constexpr Functions

November 15, 2016

/

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

userdefinedTypes

constexpr – Variables and Objects

November 13, 2016

/

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

/

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

inline

inline

November 7, 2016

/

Thanks to inline, the compiler can replace the function call with the function body. There are two reasons…

null

The Null Pointer Constant nullptr

November 6, 2016

/

The new null pointer nullptr cleans up in C++ with the ambiguity of 0 and the macro NULL. The number…

Latest news

A Lock-Free Stack: Atomic Smart PointerFebruary 17, 2025 - 11:47 am
The easiest way to solve this memory leak issue from the last post is to use a std::shared_ptr. Atomic Smart Pointer There are two ways to apply atomic operations on a std::shared_ptr: In C++11, you can use the free atomic functions on std::shared_ptr. With C++20, you can use atomic smart pointers. C++11 Using atomic operations […]
A Lock-Free Stack: A Complete ImplementationFebruary 10, 2025 - 3:01 pm
My last lock-free stack implementation was incomplete. It only supported push operations. Let’s change this. The following paragraph about sequential consistency is optional. You can easily ignore it. Sequential Consistency In my examples, I use the default memory ordering: sequential consistency. The reason is simple. Sequential consistency provides the strongest guarantees of all memory ordering […]
My Next Mentoring Program: “Generic Programming (Templates) with C++” startsFebruary 4, 2025 - 4:51 pm
My next mentoring program, “Embedded Programming with Modern C++,” starts on January 31st. Registration is open. Here are more details. Embedded Programming with Modern C++ The mentoring program consists of 16 stations. You have to invest at least 3 hours per week for each one. This means the program takes four months, and you can […]
A Lock-Free Stack: A Simplified ImplementationFebruary 3, 2025 - 10:37 am
Today, I continue my mini story about lock-free data structures. General Considerations From the outside, the caller’s responsibility (application) is to protect the data. From inside, the data structure is responsible for protecting itself. A data structure that protects itself so a data race cannot appear is called thread-safe. First, what general considerations must you […]
Deferred Reclamation in C++26: Read-Copy Update and Hazard PointersJanuary 27, 2025 - 12:23 pm
Before I dive into lock-free programming, there’s a little bit of theory necessary. A common problem in concurrency is the so-called ABA problem. That means you read a variable twice, which returns the same value each time, A. Therefore, you conclude that nothing changed in between. But you forgot the B. Let me first use […]
std::format ExtensionJanuary 20, 2025 - 11:55 am
Displaying the address of an arbitrary pointer in C++ 20 fails but succeeds with C++26. C++20 Only void, const void, and std::nullptr_t pointer types are valid. If you want to display the address of an arbitrary pointer, you must cast it to (const) void*. // formatPointer20.cpp #include <format> #include <iostream> #include <string> int main() { […]