For datacenter applications that require tight synchronization, transactions are commonly employed for achieving concurrency while preserving correctness. Unfortunately, distributed transactions are hard to scale due to the decentralized lock acquisition and coordination protocols they employ. In this paper, we show that it is possible to achieve scalability for distributed transactions by usin...

Nonmedical use of prescription medications--particularly controlled substances--has risen dramatically in recent decades, resulting in alarming increases in overdose-related health care utilization, costs, and mortality. The Centers for Disease Control and Prevention estimate that 80% of abused and misused controlled substances originate as legal prescriptions. As such, policymakers and payers ...

This paper introduces a new lock detector for symbol timing recovery PLLs in QPSK receivers operating in AWGN channels. The detector necessitates only two samples per symbol, and these samples correspond to those required by the popular Gardner[1] timing error detector. The lock detector is characterized theoretically and through simulations. It transpires that the lock detector is selfnormaliz...

In a multiprogrammed multiprocessor system, existing lock based mechanisms hold the lock for a task during a context-switch. In this case, the time that a task holds a lock can be greatly increased, resulting in a wasted lock utilization and an increase in the average response time for tasks using the lock. An option for avoiding this problem is to release the lock held by a task during a conte...

Providing efficient access to XML documents becomes crucial in XML database systems. More and more concurrency control protocols for XML database systems were proposed in the past few years. Being an important language for addressing data in XML documents, XPath expressions are the basis of several query languages, such as XQurey and XSLT. In this paper, we propose a lock-based concurrency cont...

Two traditional approaches exist for a task that is blocked on a global resource; a task either performs a non-preemptive busy wait, i.e., spins, or suspends and releases the processor. Previously, we have shown that both approaches can be viewed as spinning either at the highest priority (HP) or at the lowest priority on the processor (LP), respectively. Based on this view, previously we have ...

Storing, querying, and updating XML documents in multi-user environments requires data processing guarded by a transactional context to assure the well-known ACID properties, particularly with regard to isolate concurrent transactions. In this paper, we introduce the taDOM tree, an extended data model which allows finegrained lock acquisition for XML documents. For this reason, we design a tail...

openshapedoor within door { booleanopen int size point hinge , lock line door open = true size = 200 hinge = \NW + {10, 0} lock = if open then hinge-{0, size} else hinge+{size, 0} door = [hinge,lock] } width = 800 length = 800 centre = {500, 500} .

A race condition is a situation where two threads manipulate a data structure simultaneously, without synchronization. Race conditions are common errors in multithreaded programming. They often lead to unintended nondeterminism and wrong results. Moreover, they are notoriously hard to diagnose, and attempts to eliminate them can introduce deadlocks. In practice, race conditions and deadlocks ar...

Using a sample of 151 banks over the period 2003 to 2010, this paper estimates a model that examines the effect of switching costs in the Chinese loan market on banking profitability. In keeping with the extant empirical literature it reports a positive relationship between bank profitability and switching costs. Furthermore it reports the estimation of a systems model of switching costs and pr...