A shared data structure is lock-free if its operations do not require mutual exclusion. If one process is interrupted in the middle of an operation, other processes will not be prevented from operating on that object. In highly concurrent systems, lock-free data structures avoid common problems associated with conventional locking techniques, including priority inversion, convoying, and difficulty of avoiding deadlock. This paper introduces transactional memory, a new multiprocessor architecture intended to make lock-free synchronization as efficient (and easy to use) as conventional techniques based on mutual exclusion. Transactional memory allows programmers to define customized read-modify-write operations that apply to multiple, independently-chosen words of memory. It is implemented by straightforward extensions to any multiprocessor cache-coherence protocol. Simulation results show that transactional memory matches or outperforms the best known locking techniques for simple benchmarks, even in the absence of priority inversion, convoying, and deadlock.

/pdf/transactional-memory-architectural-support-for-lock-free-4e7zw2v6tu.pdf

Transactional memory: architectural support for lock-free data structures

A system for utilizing metadata created either at a central location for shared use by connected users, or at each individual user's location, to enhance user's enjoyment of available broadcast programming content. A variety of mechanisms are employed for automatically and manually identifying and designating programming segments, associating descriptive metadata which the identified segments, distributing the metadata for use at client locations, and using the supplied metadata to selectively record and playback desired programming.

Audio and video program recording, editing and playback systems using metadata

This ebook is the first authorized digital version of Kernighan and Ritchie's 1988 classic, The C Programming Language (2nd Ed.). One of the best-selling programming books published in the last fifty years, "K&R" has been called everything from the "bible" to "a landmark in computer science" and it has influenced generations of programmers. Available now for all leading ebook platforms, this concise and beautifully written text is a "must-have" reference for every serious programmers digital library.

As modestly described by the authors in the Preface to the First Edition, this "is not an introductory programming manual; it assumes some familiarity with basic programming concepts like variables, assignment statements, loops, and functions. Nonetheless, a novice programmer should be able to read along and pick up the language, although access to a more knowledgeable colleague will help."

The C programming language

Cell phones and other portable devices are equipped with a variety of technologies by which existing functionality can be improved, and new functionality can be provided. Some relate to visual search capabilities, and determining appropriate actions responsive to different image inputs. Others relate to processing of image data. Still others concern metadata generation, processing, and representation. Yet others relate to coping with fixed focus limitations of cell phone cameras, e.g., in reading digital watermark data. Still others concern user interface improvements. A great number of other features and arrangements are also detailed.

Methods and Systems for Content Processing

The most exciting development in parallel computer architecture is the convergence of traditionally disparate approaches on a common machine structure. This book explains the forces behind this convergence of shared-memory, message-passing, data parallel, and data-driven computing architectures. It then examines the design issues that are critical to all parallel architecture across the full range of modern design, covering data access, communication performance, coordination of cooperative work, and correct implementation of useful semantics. It not only describes the hardware and software techniques for addressing each of these issues but also explores how these techniques interact in the same system. Examining architecture from an application-driven perspective, it provides comprehensive discussions of parallel programming for high performance and of workload-driven evaluation, based on understanding hardware-software interactions.


* synthesizes a decade of research and development for practicing engineers, graduate students, and researchers in parallel computer architecture, system software, and applications development

* presents in-depth application case studies from computer graphics, computational science and engineering, and data mining to demonstrate sound quantitative evaluation of design trade-offs 

* describes the process of programming for performance, including both the architecture-independent and architecture-dependent aspects, with examples and case-studies

* illustrates bus-based and network-based parallel systems with case studies of more than a dozen important commercial designs

Table of Contents

1 Introduction 
2 Parallel Programs 
3 Programming for Performance 
4 Workload-Driven Evaluation 
5 Shared Memory Multiprocessors 
6 Snoop-based Multiprocessor Design 
7 Scalable Multiprocessors
8 Directory-based Cache Coherence
9 Hardware-Software Tradeoffs 
10 Interconnection Network Design 
11 Latency Tolerance 
12 Future Directions 
APPENDIX A Parallel Benchmark Suites

Parallel Computer Architecture: A Hardware/Software Approach

Software-controlled data prefetching is a promising technique for improving the performance of the memory subsystem to match today’s high-performance processors. While prefctching is useful in hiding the latency, issuing prefetches incurs an instruction overhead and can increase the load on the memory subsystem. As a resu 1~ care must be taken to ensure that such overheads do not exceed the benefits. This paper proposes a compiler algorithm to insert prefetch instructions into code that operates on dense matrices. Our algorithm identiEes those references that are likely to be cache misses, and issues prefetches only for them. We have implemented our algorithm in the SUfF (Stanford University Intermediate Form) optimizing compiler. By generating fully functional code, we have been able to measure not only the improvements in cache miss rates, but also the oversdl performance of a simulated system. We show that our algorithm significantly improves the execution speed of our benchmark programs-some of the programs improve by as much as a factor of two. When compared to an algorithm that indiscriminately prefetches alf array accesses, our algorithm can eliminate many of the unnecessary prefetches without any significant decrease in the coverage of the cache misses.

Design and evaluation of a compiler algorithm for prefetching

In today's fast-paced world, while the number of channels of television programming available is increasing rapidly, the time available to watch them remains the same or is decreasing. Users desire the capability to watch the programs time-shifted (on-demand) and/or to watch just the highlights to save time. In this paper we explore how to provide for the latter capability, that is the ability to extract highlights automatically, so that viewing time can be reduced.We focus on the sport of baseball as our initial target—it is a very popular sport, the whole game is quite long, and the exciting portions are few. We focus on detecting highlights using audio-track features alone without relying on expensive-to-compute video-track features. We use a combination of generic sports features and baseball-specific features to obtain our results, but believe that may other sports offer the same opportunity and that the techniques presented here will apply to those sports. We present details on relative performance of various learning algorithms, and a probabilistic framework for combining multiple sources of information. We present results comparing output of our algorithms against human-selected highlights for a diverse collection of baseball games with very encouraging results.

/pdf/automatically-extracting-highlights-for-tv-baseball-programs-baac9me619.pdf

Automatically extracting highlights for TV Baseball programs

A system and method for teleconferencing and recording of meetings. The system uses a variety of capture devices (a novel 360° camera, a whiteboard camera, a presenter view camera, a remote view camera, and a microphone array) to provide a rich experience for people who want to participate in a meeting from a distance. The system is also combined with speaker clustering, spatial indexing, and time compression to provide a rich experience for people who miss a meeting and want to watch it afterward.

system and method for distributed meetings

A human viewing temporally-dimensioned content of a multimedia document through use of a computer can add substantive content to temporally-dimensioned content of the multimedia document to thereby annotate, comment upon, and augment the multimedia document. Thus, a multimedia document becomes a basis for collaborative work. The substantive content added by the viewing user is in the form of a temporal annotation which identifies a particular relative time in temporally-dimensioned content of the multimedia document and which includes user-authored content provided by the viewing user. Display of the multimedia document includes presentation of the temporal annotations created by the user. A graphical user interface enables the user to select a temporal annotation from a list and immediately proceed to presentation of the multimedia document such that temporally-dimensioned content is presented at the particular relative time represented by the selected temporal annotation. In addition, as temporally-dimensioned content of the multimedia document is displayed, temporal annotations are. represented in the display of the multimedia document as the particular relative time represented by each temporal annotation is reached. Thus, the user-authored content becomes part of the display of the multimedia document in a temporal context.

Annotating temporally-dimensioned multimedia content

The production of synchronization scripts and associated annotated multimedia streams for servers and client computers coupled to each other by a diverse computer network which includes local area networks (LANs) and/or wide area networks (WANs) such as the intermet. Annotated multimedia streams can include a compressed video stream for display in a video window, an accompanying compressed audio stream and annotations. Synchronization scripts include annotation streams for synchronizing the display of video streams with annotations, e.g., displayable events, such textual/graphical data in the form of HTML pages with Java applets to be displayed in one or more event windows. The producer includes a capture module and an author module for capturing video streams and generating annotation streams, respectively. The capture module compresses the video stream using a suitable compression format. Annotation streams include annotation frames which provide either pointer(s) to the event(s) of interest or include displayable data embedded within the annotation stream. Accordingly, each annotation frame includes either an event locator or an event data. In addition, each annotation frame includes an event time marker which corresponds to the time stamp(s) of associated video frame(s) within the video stream. Embedded displayable data include ticker tape data embedded within the annotation stream. Examples of event locators to displayable events include URL addresses pointing to HTML web pages. The video/audio streams and annotation streams are stored in stream server(s) for subsequent retrieval by client computer(s) in a coordinated manner, so that the client computer(s) is able to synchronously display the video frames and displayable event(s) in a video window and event window(s), respectively. In one implementation, annotation streams include a flipper stream for locating HTML pages and a ticker stream which include ticker (tape) data.

Anoop Gupta

Papers

Design and evaluation of a compiler algorithm for prefetching

Automatically extracting highlights for TV Baseball programs

system and method for distributed meetings

Annotating temporally-dimensioned multimedia content

Production of a video stream with synchronized annotations over a computer network