Excerpt from Efficient Synchronization on Multiprocessors With Shared Memory A new formalism is given for read-modify-write (rmw) synchronization opera tions. This formalism is used to extend the memory reference combining mechan ism, introduced in the nyu Ultracomputer, to arbitrary rmw operations. A for mal correctness proof of this combining mechanism is given. General requirements for the practicality of combining are discussed. Combining is shown to be practical for many useful memory access Operations. This includes memory updates of the form mem_val mem_val op val, where op need not be associative, and a variety of synchronization primitives. The computation involved is shown to be closely re lated to parallel prefix evaluation. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Zusammenfassung: This book offers a comprehensive survey of shared-memory synchronization, with an emphasis on "systems-level" issues. It includes sufficient coverage of architectural details to understand correctness and performance on modern multicore machines, and sufficient coverage of higher-level issues to understand how synchronization is embedded in modern programming languages. The primary intended audience for this book is "systems programmers"--the authors of operating systems, library packages, language run-time systems, concurrent data structures, and server and utility programs. Much of the discussion should also be of interest to application programmers who want to make good use of the synchronization mechanisms available to them, and to computer architects who want to understand the ramifications of their design decisions on systems-level code

The workshop on Scalable Shared Memory Multiprocessors took place on May 26 and 27 1990 at the Stouffer Madison Hotel in Seattle, Washington as a prelude to the 1990 International Symposium on Computer Architecture. About 100 participants listened for two days to the presentations of 22 invited The motivation for this workshop was to speakers, from academia and industry. promote the free exchange of ideas among researchers working on shared-memory multiprocessor architectures. There was ample opportunity to argue with speakers, and certainly participants did not refrain a bit from doing so. Clearly, the problem of scalability in shared-memory multiprocessors is still a wide-open question. We were even unable to agree on a definition of "scalability". Authors had more than six months to prepare their manuscript, and therefore the papers included in this proceedings are refinements of the speakers' presentations, based on the criticisms received at the workshop. As a result, 17 authors contributed to these proceedings. We wish to thank them for their diligence and care. The contributions in these proceedings can be partitioned into four categories 1. Access Order and Synchronization 2. Performance 3. Cache Protocols and Architectures 4. Distributed Shared Memory Particular topics on which new ideas and results are presented in these proceedings include: efficient schemes for combining networks, formal specification of shared memory models, correctness of trace-driven simulations,synchronization, various coherence protocols, .

From driving, flying, and swimming, to digging for unknown objects in space exploration, autonomous robots take on varied shapes and sizes. In part, autonomous robots are designed to perform tasks that are too dirty, dull, or dangerous for humans. With nontrivial autonomy and volition, they may soon claim their own place in human society. These robots will be our allies as we strive for understanding our natural and man-made environments and build positive synergies around us. Although we may never perfect replication of biological capabilities in robots, we must harness the inevitable emergence of robots that synchronizes with our own capacities to live, learn, and grow. This book is a snapshot of motivations and methodologies for our collective attempts to transform our lives and enable us to cohabit with robots that work with and for us. It reviews and guides the reader to seminal and continual developments that are the foundations for successful paradigms. It attempts to demystify the abilities and limitations of robots. It is a progress report on the continuing work that will fuel future endeavors. Table of Contents: Part I: Preliminaries/Agency, Motion, and Anatomy/Behaviors / Architectures / Affect/Sensors / Manipulators/Part II: Mobility/Potential Fields/Roadmaps / Reactive Navigation / Multi-Robot Mapping: Brick and Mortar Strategy / Part III: State of the Art / Multi-Robotics Phenomena / Human-Robot Interaction / Fuzzy Control / Decision Theory and Game Theory / Part IV: On the Horizon / Applications: Macro and Micro Robots / References / Author Biography / Discussion