If I use locks, can my algorithm still be lock-free?

Posted by Joe Pension on Programmers See other posts from Programmers or by Joe Pension
Published on 2012-03-23T22:03:18Z Indexed on 2012/03/23 23:39 UTC
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multithreading

A common definition of lock-free is that at least one process makes progress. ¹

If I have a simple data structure such as a queue, protected by a lock, then one process can always make progress, as one process can acquire the lock, do what it wants, and release it.

So does it meet the definition of lock-free?

¹ See eg M. Herlihy, V. Luchangco, and M. Moir. Obstruction-free synchronization: Double-ended queues as an example. In Distributed Computing, 2003. "It is lock-free if it ensures only that some thread always makes progress".

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