Unbounded growth of heap memory degrades performance and eventually causes program failure. Traditional memory leaks are the most commonly recognized, but not the only cause of this issue. Large software systems use many aggregate data structures that can grow arbitrarily, and application behavior that produces unbounded growth of these structures is common. This growth can remain undetected by both memory leak and staleness detection tools. In this paper, we present an approach for reliably identifying aggregate data structures that can grow without bound over the lifetime of a program. Our solution tracks all aggregates over the lifetime of the program and utilizes heuristics to identify non-convergent growth. Our diagnostic method continuously reduces false positives and false negatives during execution, producing more accurate reports for as long as it is allowed to continue execution. In addition, we present techniques to utilize this method in large, pre-existing C++ software without requiring extensive code modification. Our tool identified data structures with this issue in Google's Chrome web browser and Apple's Safari browser among others.

SUMMARY Large virtual environments with many interactive objects pose high processing overhead for physics simulation and require real‐time results. Most of these objects are not being interacted with at the same time, leaving many in physical equilibrium. Modern physics simulation software eliminates some work for the case of objects at rest, but these objects still pose overhead because of potential activation during processing, which can constitute the majority of running time for some environments. We present a physics software design that eliminates overhead associated with bodies at rest, reducing the remaining running time to be proportional to the number of objects being interacted with. Our design consists of specific broad phase collision detection, contact group generation, and object storage methods, as well as intermediate structures and interfacing methods within the physics pipeline. It can be combined with various narrow phase collision detection, constraint solving, and integration techniques, as well as methods of parallelism. We show that our system produces a running time independent of the number of objects at rest, and that our methods compare favorably with published methods and available physics software when simulating environments with many objects at rest. CR Categories: I.3.6 [Computer graphics]: Methodology and techniques—Graphics data structures and data types; I.3.7 [Computer graphics]: Three‐dimensional graphics and realism—virtual reality. Copyright © 2011 John Wiley & Sons, Ltd.

Abstract The creation of a contemporary artwork –The Scalable City—explores the possibilities and implications of new technologies in general and the Cell processor (CP) in particular. In general, new technologies provide new methods for describing and acting in the world. Creating new forms of art can be a means of understanding and furthering this process; however, this has not been the typical relationship between the leading edges of cultural and technological experiments in the 20 th century. The approaches taken to create The Scalable City provide an example of how these goals can correlate in an effective way, as its aim is the creation of a 3D interactive graphics application, highlighting the ongoing algorithmicization of the world at large. In its creation, computational bottlenecks have been encountered, which compromised its aesthetic and conceptual goals. The core component of this work is a world depicting transforming landscapes, networks of roads and emergent structures. Within the operation of the artwork, each is transformed by interactions of the viewer, algorithms and the initial data. The computational demands of some of these transformations exceed the capability of standard methods using a single host compute environment. Sheldon Brown and the members of his Experimental Game Lab at the Center for Research in Computing and the Arts at UCSD developed means of using CP compute servers to overcome these limitations. The authors detail their encounters with Cell processing, from initial efforts, discovery of the affordances and limitations of Cell processing, and its eventual application to the project. Copyright © 2009 John Wiley & Sons, Ltd.

The Scalable City is a set of projects that explore the externalization of algorithmic approaches to urbanization that intersect with geographic, political, economic and aesthetic zones of conflict. Version 0.7a of the Scalable City is a multi-media exhibition consisting of various manifestations of landscape demarcation, personal embodiment and domicile transformations. Procedures governing the arrangement and operations of these discrete areas, are interchanged across domains - moving them from a more familiar basis to distorted and exaggerated extremes of patterns and juxtapositions. Through these processes, which reveal the procedural basis of the development of cultural forms, the mechanistic processes of social formation are highlighted. The forum for this version of the work is the US/Mexican border where collisions of cultural forms, political structures, economies and landscape are distinctly overt.

Smoke and Mirrors is an artwork created by Sheldon Brown that is now on exhibit at Reuben H. Fleet Science Center in San Diego. Smoke and Mirrors allows two to six visitors at a time to enter into a shared virtual environment through their own projected computer graphic media portal. The environment engages viewers in a series of activities drawn from the cultural and social history of tobacco usage.Participants first have their faces 3-dimensionally scanned. Then they find which of the kiosks their scanned face has been sent to. The first stage of the narrative attaches their face to an avatar created out of an isolated biological system. The user now navigates this avatar through a series of maze-like environments.While in the shared virtual world, users can see the actions that all participants are undertaking. Each environment responds to people's movements through them, further revealing the ways in which an image of this particular product has been constructed over the years, using both overt and covert strategies.