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Lexicon Entry

Futex (Fast Userspace Mutex)

A Linux kernel mechanism that provides a fast, lightweight synchronization primitive. It avoids the overhead of a system call when a lock is uncontested by managing the lock state entirely in userspace atomic operations.

Related Knowledge & Cross-References

Guide

Windows Threads and Synchronization: Win32 API and NT Primitives

A deep dive into Windows multithreading. Learn how to manage threads with CreateThread, synchronize using SRWLocks, and build high-performance blocking mechanisms with WaitOnAddress (the Windows futex).

Guide

POSIX Threads and Linux Synchronization: The Magic of Futex

A deep dive into thread creation with pthreads and how Linux avoids system calls in fast path synchronization using futexes.