Composite Abortable Locks

The need to allow threads to abort an attempt to acquire a lock (sometimes called a timeout) is an interesting new requirement driven by state-of-the-art database applications with soft real-time constraints. This paper presents a new composite abortable lock (CAL), a combination of abortable queue-based (QL) and test-andset based backoff (BL) lock mechanisms, which provides non-blocking aborts while ensuring low space requirements without need for a memory reclamation scheme. The key observation motivating our approach is that the fast lock hand-off achieved by QLs only requires the first few threads to be queued (not all waiting threads), and that the remaining threads can run as in a BL. We developed an algorithm that uses only a short fixed size structure for queueing, allowing most threads to back-off. This reduces worst-case space overhead dramatically, and improves performance by eliminating the need for expensive and complicated memory management mechanisms. Experimental ...

• Type: Conference
• Year: 2006
• Where: IPPS
• Authors: Virendra J. Marathe, Mark Moir, Nir Shavit
• Keywords: Composite Abortable Lock, Distributed And Parallel Computing, IPPS 2006, Lock Mechanisms, Threads