Highly concurrent and reliable data objects are vital for parallel programming. Lock-free shared data objects are highly concurrent and guarantee that at least one operation, from a set of concurrently executed operations, finishes after a finite number of steps regardless of the state of the other operations. Lock-free data objects provide progress guarantees on the object level. In this paper...

This paper reports the development and field testing of DVLNAV, an interactive program for precision three-dimensional navigation of underwater vehicles. The goal of this system is to provide vehicle position and velocity navigation data with both the precision and update rate necessary to enable closed-loop vehicle control. We report the results of preliminary field trials of DVLNAV with the J...

Some microorganisms, such as spermatozoa, synchronize their flagella when swimming in close proximity. Using a simplified model (two infinite, parallel, two-dimensional waving sheets), we show that phase locking arises from hydrodynamics forces alone, and has its origin in the front-back asymmetry of the geometry of their flagellar waveform. The time evolution of the phase difference between co...

The paper studies the impact of several lock manager designs on the overhead imposed to a persistent programming language by automated object locking. Our study reveals that a lock management method based on lock state sharing outperforms more traditional lock management designs. Lock state sharing is a novel lock management method that represents all lock data structures with equal values with...

From a project on upgrading an existing commercially used operating system for support of a distributed system architecture, we present results and experience from a comprehensive analytical performance evaluation of a large number of different implementation strategies for distributed lock management. The various lock management policies we consider differ in the management of the lock databas...