cycleburn - How to switch off gcc Optimization for a C Source Code Region
August 3, 2025
gcc allows to switch off optimization temporarily for a source code region. This post shows the RPCL word cycleburn as an example.
C
RHPool - Rendezvous Hashing for fast DSR Load Balancing
July 23, 2025
RHPool implements a Rendezvous Hash Pool, which holds multiple possible destinations (or servers) at a given time. For DSR load balancing (the intended purpose), a MAC address is mapped to the first 6 bytes in memory order, the remaining 2 bytes allow to insert the same MAC address multiple times. A combination of Linux/POSIX rwlocks and atomic uint64_t access allows a maximum of concurrency during regular operation.
RPCL - Reverse Polish Configuration (and Control) Language
June 28, 2025
RPCL is a minimalistic configuration and control language, initially designed to act as a CLI for daemon-like background processes. RPCL is an acronym for Reverse Polish Configuration (and Control) Language.
CHRing - An experimental Skiplist based Consistent Hash Ring
June 4, 2025
CHRing is an experimental consistent hash ring implementation based on a skiplist and f448(), a tabulation hashing function for this purpose. This post provides an overview of the CHRing testing API and the related RPCL control words.
f2568() - A variable Length Tabulation Hash Function
June 1, 2025
f2568() is a variable length tabulation hashing function which returns a 64 bit hash result of input data up to a size of 256 bytes. It’s fast (requiring as many XOR operations as the data length in bytes), easy to understand and very strong at the same time. f2568() is publicly available under the BSD-3-Clause License.
f448() - Another Tabulation Hash Function to implement a consistent Hash Ring
May 4, 2025
f448() is another tabulation hashing function which maps two uint32_t to an uniform hash result of type uint64_t. This is useful to implement a skiplist based consistent hash ring with 2^64 possible ring slots (or positions).
f82() - A Hash Function with strong theoretical Properties
April 2, 2025
f82() is hash function which hashes a unt64_t 8 byte unsigned integer key to a uint16_t 2 byte hash value. It belongs to the class of tabulation hashing functions and is perfect for implementing lock-less hash tables and other data structures that require an uniform and perfect distribution.
Uniform random numbers in an integer interval in C
March 6, 2025
When uniform random numbers are needed in C, just applying modulo is not enough. With using random() for portability and a few calculations this can be easily fixed.
C23 and stdatomic.h
March 5, 2025
C23, formally ISO/IEC 9899:2024, is the current open standard for the C programming language, which supersedes C17 (standard ISO/IEC 9899:2018).