Search results for "Shared memory"

2016

The growth of next-generation sequencing (NGS) datasets poses a challenge to the alignment of reads to reference genomes in terms of alignment quality and execution speed. Some available aligners have been shown to obtain high quality mappings at the expense of long execution times. Finding fast yet accurate software solutions is of high importance to research, since availability and size of NGS datasets continue to increase. In this work we present an efficient parallelization approach for NGS short-read alignment on multi-core clusters. Our approach takes advantage of a distributed shared memory programming model based on the new UPC++ language. Experimental results using the CUSHAW3 alig…

SAUCE: A Web-Based Automated Assessment Tool for Teaching Parallel Programming

2015

Many curricula for undergraduate studies in computer science provide a lecture on the fundamentals of parallel programming like multi-threaded computation on shared memory architectures using POSIX threads or OpenMP. The complex structure of parallel programs can be challenging, especially for inexperienced students. Thus, there is a latent need for software supporting the learning process. Subsequent lectures may cover more advanced parallelization techniques such as the Message Passing Interface (MPI) and the Compute Unified Device Architecture (CUDA) languages. Unfortunately, the majority of students cannot easily access MPI clusters or modern hardware accelerators in order to effectivel…

Analyzing the performance of a cluster-based architecture for immersive visualization systems

2008

Cluster computing has become an essential issue for designing immersive visualization systems. This paradigm employs scalable clusters of commodity computers with much lower costs than would be possible with the high-end, shared memory computers that have been traditionally used for virtual reality purposes. This change in the design of virtual reality systems has caused some development environments oriented toward shared memory computing to require modifications to their internal architectures in order to support cluster computing. This is the case of VR Juggler, which is considered one of the most important virtual reality application development frameworks based on open source code. Thi…

Concurrent Computing with Shared Replicated Memory

2019

Any concurrent system can be captured by a concurrent Abstract State Machine (cASM). This remains valid, if different agents can only interact via messages. It even permits a strict separation between memory managing agents and other agents that can only access the shared memory by sending query and update requests. This paper is dedicated to an investigation of replicated data that is maintained by a memory management subsystem, where the replication neither appears in the requests nor in the corresponding answers. We specify the behaviour of a concurrent system with such memory management using concurrent communicating ASMs (ccASMs), provide several refinements addressing different replic…

Parallelization strategies for density matrix renormalization group algorithms on shared-memory systems

2003

Shared-memory parallelization (SMP) strategies for density matrix renormalization group (DMRG) algorithms enable the treatment of complex systems in solid state physics. We present two different approaches by which parallelization of the standard DMRG algorithm can be accomplished in an efficient way. The methods are illustrated with DMRG calculations of the two-dimensional Hubbard model and the one-dimensional Holstein-Hubbard model on contemporary SMP architectures. The parallelized code shows good scalability up to at least eight processors and allows us to solve problems which exceed the capability of sequential DMRG calculations.

Decentralized Coordination System for Multiple AGVs in a Structured Environment

2011

Abstract In this paper, we propose a decentralized coordination algorithm for safe and efficient management of a group of mobile robots following predefined paths in a dynamic industrial environment. The proposed algorithm is based on shared resources and proved to guarantee ordered traffic flows avoiding collisions and deadlocks. In consistency with the model of distributed robotic systems (DRS), no centralized mechanism, synchronized clock, shared memory or ground support is needed. A local inter-robot communication is required among a small number of spatially adjacent robotic units.

Randomized renaming in shared memory systems.

2021

Abstract Renaming is a task in distributed computing where n processes are assigned new names from a name space of size m . The problem is called tight if m = n , and loose if m > n . In recent years renaming came to the fore again and new algorithms were developed. For tight renaming in asynchronous shared memory systems, Alistarh et al. describe a construction based on the AKS network that assigns all names within O ( log n ) steps per process. They also show that, depending on the size of the name space, loose renaming can be done considerably faster. For m = ( 1 + ϵ ) ⋅ n and constant ϵ , they achieve a step complexity of O ( log log n ) . In this paper we consider tight as well as loos…

Memory Resource Management for Real-Time Systems

2007

Dynamic memory storage has been widely used for years in computer science. However, its use in real-time systems has not been considered as an important issue, and memory management has not receive much consideration, whereas today's real-time applications are often characterized by highly fluctuating memory requirements. In this paper we present an approach to dynamic memory management for real-time systems. In response to application behavior and requests, the underlying memory management system adjusts resources to meet changing demands and user needs. The architectural framework that realizes this approach allows adaptive allocation of memory resources to applications involving both per…

The differences between distributed shared memory caching and proxy caching

2000

The authors discuss the similarities in caching between the extensively studied distributed shared memory systems and the emerging proxy systems. They believe that several of the techniques used in distributed shared memory systems can be adapted and applied to proxy systems.

Distributed Multi-level Motion Planning for Autonomous Vehicles in Large Scale Industrial Environments

2013

In this paper we propose a distributed coordination algorithm for safe and efficient traffic management of heterogeneous robotic agents, moving within dynamic large scale industrial environments. The algorithm consists of a distributed resource--sharing protocol involving a re--planning strategy. Once every agent is assigned with a desired motion path, the algorithm ensures ordered traffic flows of agents, that avoid inter--robot collision and system deadlock (stalls). The algorithm allows multi--level representation of the environment, i.e. large or complex rooms may be seen as a unique resource with given capacity at convenience, which makes the approach appealing for complex industrial e…