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acquireReleaseWithWaiting

Acquire-Release Semantics – The Typical Misunderstanding

July 16, 2016

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A release operation synchronizes-with an acquire operation on the same atomic variable. So we can easily…

poll

100 Posts Anniversary – Quo vadis Modernes C++?

July 13, 2016

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As you may know, I translate in this blog the posts from my German blog into English. My German blog…

trans

Transitivity of the Acquire-Release Semantic

July 12, 2016

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A release operation synchronizes with an acquire operation on the same atomic variable and establishes,…

acquireReleaseConsume

memory_order_consume

July 9, 2016

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std::memory_order_consume is the most legendary of the six memory models. That's for two reasons. On…

criticalRegion

Acquire-Release Semantic

July 4, 2016

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With the acquire-release semantics, the memory model gets very thrilling. Because now, we do not have…

producerConsumer

Sequential Consistency applied

July 2, 2016

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I have introduced In the post Sequential Consistency the default memory model. This model, in which all…

atomicOperationsReadWriteEng

Synchronization and Ordering Constraints

June 28, 2016

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In this post, our tour through the c++ memory model goes one step deeper. Until now, the posts were only…

Atomics

June 22, 2016

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In addition to booleans, there is atomics for pointers, integrals, and user-defined types. The rules…

conditionVariableAtomic

The Atomic Boolean

June 21, 2016

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The remaining atomics - in contrast to std::atomic_flag - are partial or full specializations of the…

twoAtomics

Sequential Consistency

June 19, 2016

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The atomics are the base of the C++ memory model. Per default, sequential consistency is applied. The…

BackgroundCpp

The Facebook Group Modernes C++

June 18, 2016

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I created the facebook group Modernes C++. I see one big advantage in this group. I…

spinLockSleep

The Atomic Flag

June 17, 2016

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Atomics guarantee two characteristics. On the one hand, they are atomic, on the other, they provide synchronization…

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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 […]
A Lock-Free Stack: A Hazard Pointer Implementation Explained IMarch 24, 2025 - 11:37 am
In my last post, I presented a hazard pointer implementation: A Lock-Free Stack: A Hazard Pointer Implementation. Today, I will explain the implementation. MyNode is a class template, parametrized by the type it holds: data. MyNode models the concept Node. template <typename T> concept Node = requires(T a) { {T::data}; { *a.next } -> std::same_as<T&>; […]
A Lock-Free Stack: A Hazard Pointer ImplementationMarch 10, 2025 - 11:42 am
Hazard Pointers solve all issues of the previous implementation: A Lock-Free Stack: A Simple Garbage Collector. From one Week to two Weeks You may have already noticed. I will change my blog publishing frequency from one to two weeks in the future. Writing a post using your voice is exceptionally exhausting and time-consuming. Hazard Pointers […]
A Lock-Free Stack: A Simple Garbage CollectorFebruary 24, 2025 - 11:58 am
My next lock-free stack includes a simple garbage collector. I discussed the concurrent execution of more than one topAndPush call is a Race Condition. I can safely delete a node if not more than one topAndPush call is executing concurrently. This observation is crucial for solving this memory leak issue: I store removed nodes on […]
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 […]