If you are in an environment where you can guarantee that a piece of code runs in bounded time (no interrupts, no faults, etc), then locks can actually be used in lock-free algorithms since code inside the lock will always be making forward progress and will exit in or before some deterministic time. If the lock is fair and there's a bounded number of threads accessing the lock, then it technically becomes wait-free under these conditions since time to completion is bounded by n_threads * task_time;This environment only happens to exist in very specific and uncommon settings, so it's not a generally useful concept for lock-free programming. It's common in the linux kernel to see spinlocks taken in sections which have disabled all interrupts, for example, but this is not an environment that normal programs can live in.
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