As part of Time Warner's interactive TV trial in Orlando, Florida, we have implemented mechanisms for the construction of highly available and scalable system services and applications. Our mechanisms rely on an underlying distributed objects architecture, similar to Spring[1]. We have extended a standard name service interface to provide selectors for choosing among service replicas and auditing to allow the automatic detection and removal of unresponsive objects from the name space. In addition, our system supports resource recovery, by letting servers detect client failures, and automated restart of failed services. Our experience has been that these mechanisms greatly simplify the development of services that are both highly available and scalable. The system was built in less than 15 months, is currently in a small number of homes, and will support the trial's 4,000 users later this year. 1 Introduction Interactive TV (ITV) is a new application domain for distributed systems. Alt...

Conventional windowing environments provide separate classes of objects for user interface components, or “widgets,” and graphical objects. Widgets negotiate layout and can be resized as rectangles, while graphics may be shared, transformed, transparent, and overlaid. This presents a major obstacle to applications like user interface builders and compound document editors where the manipulated objects need to behave both like graphics and widgets.

Current time-based presentation systems are rigid in that they assume the running time of all components of a presentation is constant.Furthermore, most systems offer little or no supportfordynamically adapting the presentation quality to the (lack of) available system resources.In this paper, we introduce an object called a Pacer that is "timeelastic" in that it can adjust the quality of its presentation according to the amount of time available.We have implemented a direct manipulation graphical interface using pacers that can automatically degrade presentation quality in a controlled fashion depending on the user's input rate and the speed of the rendering system.

Traditional document editors are large and complex.Using first-class objects to represent individual characters in a document, we have implemented an editor that is much smaller and simpler than editors of comparable power.This editor, named "Dot", uses object sharing to reduce memory usage and an incremental update strategy to minimize screen redraw time.Our measurements show the current Dot implementation uses 10 bytes for each character in a document and 30 bytes for each visible character.On a IO-MIPS workstation, Dot can draw over 10 full pages per second and can keep pace with interactive typing speeds.These measurements and our experience using Dot shows that a fully object-oriented approach to document editing is practical.We used the editor to prepare and publish this paper.

Linking is traditionally a batch process that resolves cross-references between object modules and run-time libraries to produce a stand-alone executable image. Because most program changes only involve a small part of the program, we have implemented an incremental linker, named Inclink, that processes only the changed modules. Inclink generates a new executable in time proportional to the size of change; in contrast, a batch linker generates an executable in time proporitonal to the size of the program. To minimize updates to the executable, Inclink allocates extra space for every module. By allocating 24 percent more space in the executable for overflows, Inclink can update a module in place over 97 percent of the time. Measurements show that Inclink is more than an order of magnitude faster than the UNIX [2] batch linker and that 88 percent of all links will take less than 2 s of CPU time on a MicroVAX-2, independent of program size.

The two goals of graphics performance analysis are to characterize application workloads and to understand how systems perform under these workloads. We have developed a set of tools to help achieve these goals. TGEN is a tracing program that intercepts graphics library calls from an application program and records them in a file. TPROF is a profiler that interprets a trace file and computes workload statistics. TBENCH is a portable performance measurement tool that executes a trace file on a graphics system and measures the resulting update time. In this paper, we describe these tools and give examples of their use.

Article Glyphs: flyweight objects for user interfaces Share on Authors: Paul R. Calder Center for Integrated Systems, Stanford University, Stanford, California Center for Integrated Systems, Stanford University, Stanford, CaliforniaView Profile , Mark A. Linton Center for Integrated Systems, Stanford University, Stanford, California Center for Integrated Systems, Stanford University, Stanford, CaliforniaView Profile Authors Info & Claims UIST '90: Proceedings of the 3rd annual ACM SIGGRAPH symposium on User interface software and technologyAugust 1990 Pages 92–101https://doi.org/10.1145/97924.97935Published:01 August 1990 42citation1,304DownloadsMetricsTotal Citations42Total Downloads1,304Last 12 Months55Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

Article Free Access Share on X toolkits: the lessons learned Authors: Jarrett Rosenberg Sun Microsystems Sun MicrosystemsView Profile , Paul Asente Adobe Systems, Inc. Adobe Systems, Inc.View Profile , Mark Linton Stanford University Stanford UniversityView Profile , Andrey Palay Carnegie-Mellon University Carnegie-Mellon UniversityView Profile Authors Info & Claims UIST '90: Proceedings of the 3rd annual ACM SIGGRAPH symposium on User interface software and technologyAugust 1990 Pages 108–111https://doi.org/10.1145/97924.97937Online:01 August 1990Publication History 0citation275DownloadsMetricsTotal Citations0Total Downloads275Last 12 Months7Last 6 weeks5 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Unidraw is a framework for creating graphical editors in domains such as technical and artistic drawing, music composition, and circuit design. The Unidraw architecture simplifies the construction of these editors by proving programming abstractions that are common across domains. Unidraw defines four basic abstractions: components define operations on components, and external representations define the mapping between components and the file format generated by the editor. Unidraw also supports multiple views, graphical connectivity, and dataflow between components. This paper describes the Unidraw design, implementation issues, and three experimental domain specific editors we have developed with Unidraw: a drawing editor, a user interface builder, and a schematic capture system. Our results indicate a substantial reduction in implementation time and effort compared with existing tools.

Unidraw is a framework for creating object-oriented graphical editors in domains such as technical and artistic drawing, music composition, and CAD. The Unidraw architecture simplifies the construction of these editors by providing programming abstractions that are common across domains. Unidraw defines four basic abstractions: components encapsulate the appearance and behavior of objects, tools support direct manipulation of components, commands define operations on components, and external representations define the mapping between components and a file or database. Unidraw also supports multiple views, graphical connectivity, and dataflow between components. This paper presents Unidraw and three prototype domain-specific editors we have developed with it: a schematic capture system, a user interface builder, and a drawing editor. Experience indicates a substantial reduction in implementation time and effort compared with existing tools.

To profile the changes made to programs during development and maintenance, the authors have instrumented the 'make' utility that is used to compile and link programs. With minor modifications, they have used 'make' to find out how much time programmers spend waiting for compiling and linking, how many modules are compiled each time a program is linked, and the change in size of the compiled modules. Measurements show that most programs are relinked after only one or two modules are recompiled, and that over 90% of all recompilations yield object code that is less than 100 bytes larger in size. The authors are using these results to guide the design of an incremental programming environment, particularly with respect to an incremental linker.>