Ada (trademark) projects at NASA. Runtime environment issues and recommendations

Ada practitioners should use this document to discuss and establish common short term requirements for Ada runtime environments. The major current Ada runtime environment issues are identified through the analysis of some of the Ada efforts at NASA and other research centers. The runtime environment characteristics of major compilers are compared while alternate runtime implementations are reviewed. Modifications and extensions to the Ada Language Reference Manual to address some of these runtime issues are proposed. Three classes of projects focusing on the most critical runtime features of Ada are recommended, including a range of immediately feasible full scale Ada development projects. Also, a list of runtime features and procurement issues is proposed for consideration by the vendors, contractors and the government

Sixth Annual Users' Conference

Conference papers and presentation outlines which address the use of the Transportable Applications Executive (TAE) and its various applications programs are compiled. Emphasis is given to the design of the user interface and image processing workstation in general. Alternate ports of TAE and TAE subsystems are also covered

Generalized Portable SHMEM library for high performance computing

The Generalized Portable SHMEM library (GPSHMEM) is a portable implementation of the SHMEM library originally released by Cray Research Inc. on the Cray T3D. SHMEM and GPSHMEM realize the distributed shared memory programming model, that is, a shared memory programming model in environments in which memory is physically distributed. It is intended for use on a large variety of hardware platforms, including distributed systems with a network interconnect. The programming interface of GPSHMEM follows that of SHMEM and includes remote memory access operations (one-sided communication) and a set of collective routines such as broadcast, collection and reduction. Programming interfaces for C and Fortran are provided. Because of the minimal assumptions about the underlying hardware, GPSHMEM does not implement the full SHMEM T3D interface. The lack of a few functions is compensated by a set of extensions, including dynamic memory allocation for Fortran 77. To ease porting of SHMEM-enabled scientific Fortran 77 code from the Cray machines to use with GPSHMEM, a specialized Fortran 77 preprocessor was designed and developed

The df: A proposed data format standard

A standard is proposed describing a portable format for electronic exchange of data in the physical sciences. Writing scientific data in a standard format has three basic advantages: portability; the ability to use metadata to aid in interpretation of the data (understandability); and reusability. An improperly formulated standard format tends towards four disadvantages: (1) it can be inflexible and fail to allow the user to express his data as needed; (2) reading and writing such datasets can involve high overhead in computing time and storage space; (3) the format may be accessible only on certain machines using certain languages; and (4) under some circumstances it may be uncertain whether a given dataset actually conforms to the standard. A format was designed which enhances these advantages and lessens the disadvantages. The fundamental approach is to allow the user to make her own choices regarding strategic tradeoffs to achieve the performance desired in her local environment. The choices made are encoded in a specific and portable way in a set of records. A fully detailed description and specification of the format is given, and examples are used to illustrate various concepts. Implementation is discussed

A portability assistant for Fortran applications

This thesis addresses the issues of porting software from one machine environment to another. Some general observations are made about the definition of Portability and the design and portability of programs written in high level programming languages, in particular Fortran. Two areas of portability are considered in detail: (i) Portability Criteria and Measures - The main criteria affecting the portability of Fortran applications are identified and possible measures of the effects of these criteria considered. A Portability Function is defined for obtaining a measure of the percentage portability of Fortran programs. (ii) Portability Assistant - The use of existing analysis tools to obtain measures of the criteria affecting the portability of Fortran programs is considered. A portability assistant is provided in the form of an Ingres Relational Database, which holds die data obtained from these measures, enables the portability function to be applied to the application and assists in the porting of the application. The methods of measuring the criteria affecting Fortran programs and the use of an Ingres database as a portability assistant is then applied to a particular example, the porting of NOMIS, a large manpower database

Conference on the Programming Environment for Development of Numerical Software

Systematic approaches to numerical software development and testing are presented

Microcomputers as adaptive and protective interfaces in computer networks

Imperial Users onl