https://nalar.dev/tags/futex/ Recent content in Futex on Nalar Hugo en-us Mon, 21 Sep 2026 00:00:00 +0000 https://nalar.dev/futex-waitv-blocks-on-multiple-futex-words-in-one-wait/ Mon, 21 Sep 2026 00:00:00 +0000 https://nalar.dev/futex-waitv-blocks-on-multiple-futex-words-in-one-wait/ <p>A traditional futex wait names one futex word. That maps cleanly to a mutex or condition whose blocking state is represented by one shared 32-bit value. Some synchronization designs instead need a thread to sleep until any member of several independent states changes.</p> <p><code>futex_waitv()</code> provides that vector wait. The caller supplies an array of wait descriptors, each containing a futex address and an expected value. The kernel checks the vector and blocks only while every entry still matches its expected state.</p>