The mutual-exclusion property of locks stands in the way to scalability of parallel programs on many-core architectures. Locks do not allow progress guarantees, because a task may fail inside a critical section and keep holding a lock that blocks other tasks from accessing shared data. With non-blocking synchronization, the drawbacks of locks are avoided by synchronizing access to shared data b...

Two-phase locking is a standard method for managing concurrent transactions in database systems. In order to guarantee good recovery properties, two-phase locking should be strict, meaning that locks can be released only after the transaction's commit or abort. In this paper we show that even exclusive locks can be released immediately after the commit request has arrived, without sacriicing an...

OBJECTIVES One way law enforcement officers support firearm safety is by promoting the use of gun locks. This investigation examined law enforcement officers' willingness to use gun locks on their own guns, as well as their opinions regarding gun locks in general. SETTING Law enforcement officers from an urban agency in the southern region of the United States. METHODS Free keyed cable gun ...

In order to understand the relative expressive power of larger concurrent programming languages, we analyze translations small process calculi which model communication and synchronization processes. The source language SYNCSIMPLE is a minimalistic for message passing concurrency while target LOCKSIMPLE shared memory concurrency. former calculus with synchronous processes, latter has synchroniz...

The past few years have marked the start of a historic transition from sequential to parallel computation.The necessity to write parallel programs is increasing as systems are getting more complex while processor speed increases are slowing down. Current parallel programming uses low-level programming constructs like threads and explicit synchronization using locks to coordinate thread executio...

We present a hierarchical locking algorithm that dynamically elects a primary server in a replicated file system at various granularities. We introduce two lock types: shallow locks that control a single file or directory, and deep locks that lock everything in the subtree rooted at a directory. Experimental results show that for typical use cases, deep locks can make the overhead of replicatio...

In this paper, we propose a new approach to building synchronization primitives, dubbed “lwlocks” (short for light-weight locks). The primitives are optimized for small memory footprint while maintaining efficient performance in low contention scenarios. A read-write lwlock occupies 4 bytes, a mutex occupies 4 bytes (2 if deadlock detection is not required), and a condition variable occupies 4 ...

BACKGROUND AND OBJECTIVES This retrospective study compared the effectiveness of the timing of the antibiotic locks to clear catheter-related bacteremia in children on chronic hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The early antibiotic lock group received antibiotic locks along with systemic antibiotics from the very beginning of catheter-related bacteremia. The late anti...