We argue for transactions as the synchronization primitive of an ordering-based memory consistency model. Rather than define transactions in terms of locks, our model defines locks, conditions, and atomic/volatile variables in terms of transactions. A traditional critical section, in particular, is a region of code, bracketed by transactions, in which certain data have been privatized. Our memo...

Most multiprocessors are multiprogrammed in order to achieve acceptable response time and to increase utilization. Unfortunately, inopportune preemption may significantly degrade the performance of synchronized parallel applications. To address this problem, researchers have developed two principal strategies for concurrent, atomic update of shared data structures: preemption-safe locking and n...

Transactional memory (TM) has garnered significant interest as an alternative to existing concurrency methods due to its simplified programming model, natural composition characteristics and native support of optimistic concurrency. Yet, mutual exclusion locks are ubiquitous in existing parallel software due to their fast execution, inherent property for irreversible operations and long-standin...

Large-scale shared-memory multiprocessors typically have long latencies for remote data accesses. A key issue for execution performance of many common applications is the synchronization cost. The communication scalability of synchronization has been improved by the introduction of queue-based spin-locks instead of Test&(Test&Set). For architectures with long access latencies for global data, a...

SJ-172550 (1) was previously discovered in a biochemical high throughput screen for inhibitors of the interaction of MDMX and p53 and characterized as a reversible inhibitor (J. Biol. Chem. 2010; 285:10786). Further study of the biochemical mode of action of 1 has shown that it acts through a complicated mechanism in which the compound forms a covalent but reversible complex with MDMX and locks...

In this paper, we consider asynchronous programs consisting of multiple threads running in parallel. Each of the thread is equipped with a multi-set. The threads can create tasks and post them onto multi-sets of other threads or read a task from their own. In addition, they can synchronise through a finite set of locks. In this paper, we show that the reachability problem of such class of async...

Computers and computers embedded in everyday devices are not always as dangerous as guns, although there are many cases where they can be as dangerous. Medical devices may give patients undetected overdoses. In-car entertainment devices, like radios, may, through their badly-designed user interfaces, cause a driver to have an accident. A slip in a spreadsheet may be the first step towards an or...

Thread-based concurrent languages currently do not provide much support to (a) avoid deadlocks, (b) treat competing threads in a fair way, and (c) allow branching depending on lock availability. This makes parallel programming di cult and error prone and thus reduces the programmer's productivity. In this paper we present a lock statement for fair atomic locking of several locks that supports (...

If two parallel threads access the same location and at least one of them performs a write, a race exists. The detection of races|a major problem in parallel debugging|is complicated by the presence of atomic critical sections. In programs without critical sections, the existence of a race is usually a bug leading to nondeterministic behavior. In programs with critical sections, however, access...

Writing communication software, which spends a significant amount of time on handling incoming messages, is difficult: Active Messages are fast, but awkward to use; traditional popup threads are easy to use, but expensive. Therefore, we have implemented a portable, hybrid upcall mechanism that is easier to use than Active Messages, yet avoids unnecessary thread switching. We allow upcalls to bl...