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Software Transactional Memory (STM) is a generic synchronization construct that enables automatic conversion of correct sequential objects into correct nonblocking concurrent objects. Recent STM systems, though significantly more practical than their predecessors, display inconsistent performance: differing design decisions cause different systems to(More)
Early implementations of software transactional memory (STM) assumed that sharable data would be accessed only within transactions. Memory may appear inconsistent in programs that violate this assumption, even when program logic would seem to make extra-transactional accesses safe. Designing STM systems that avoid such inconsistency has been dubbed the(More)
In Software Transactional Memory (STM), <i>contention management</i> refers to the mechanisms used to ensure forward progress--to avoid livelock and starvation, and to promote throughput and fairness. Unfortunately, most past approaches to contention management were designed for obstruction-free STM frameworks, and impose significant constant-time(More)
—We address the recently recognized privatization problem in software transactional memory (STM) runtimes, and introduce the notion of partially visible reads (PVRs) to heuristically reduce the overhead of transparent privatization. Specifically, PVRs avoid the need for a " privatization fence " in the absence of conflict with concurrent readers. We present(More)
Transactional memory has been widely hailed as a simpler alternative to locks in multithreaded programs, but few nontriv-ial transactional programs are currently available. We describe an open-source implementation of Delaunay triangulation that uses transactions as one component of a larger parallelization strategy. The code is written in C++, for use with(More)
It is increasingly important for parallel applications to run together on the same machine. However, current performance is often poor: programs do not adapt well to dynamically varying numbers of cores, and the CPU time received by concurrent jobs can differ drastically. This paper introduces Callisto, a resource management layer for parallel runtime(More)
—We present LLAMA, a graph storage and analysis system that supports mutability and out-of-memory execution. LLAMA performs comparably to immutable main-memory analysis systems for graphs that fit in memory and significantly outperforms existing out-of-memory analysis systems for graphs that exceed main memory. LLAMA bases its implementation on the(More)
In a software transactional memory (STM) system, conflict detection is the problem of determining when two transactions cannot both safely commit. Validation is the related problem of ensuring that a transaction never views inconsistent data, which might potentially cause a doomed transaction to exhibit irreversible, externally visible side effects.(More)
We explore the potential of hardware transactional memory (HTM) to improve concurrent algorithms. We illustrate a number of use cases in which HTM enables significantly simpler code to achieve similar or better performance than existing algorithms for conventional architectures. We use Sun's prototype multicore chip, code-named Rock, to experiment with(More)
There has been considerable recent interest in both hardware andsoftware transactional memory (TM). We present an intermediateapproach, in which hardware serves to accelerate a TM implementation controlled fundamentally by software. Specifically, we describe an alert on update mechanism (AOU) that allows a thread to receive fast, asynchronous notification(More)