This tutorial presents an overview of structured design and structured programming techniques. Methods of program design and construction are discussed. Some data on structured programming experiments are presented. I...
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This tutorial presents an overview of structured design and structured programming techniques. Methods of program design and construction are discussed. Some data on structured programming experiments are presented. In addition a set of structured programming macros, embedded in the Macro-11 language and some experience gained in their construction and usage is presented.
New results are presented for the optimal scheduling of a single processor when randomness is present. The objective is to minimize the expected waiting costs of jobs per unit time. The various factors considered are ...
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New results are presented for the optimal scheduling of a single processor when randomness is present. The objective is to minimize the expected waiting costs of jobs per unit time. The various factors considered are the types of waiting cost functions, available information about the jobs, types of scheduling rules allowed, and type of arrival process. The principle results relate to the generality of SPT/C type rules, particularly to cases where arrivals are completely general.
This is the first of three papers that describe a new programming language for structured programming of computer operating systems. It extends the sequential programming language Pascal with concurrent programming to...
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This is the first of three papers that describe a new programming language for structured programming of computer operating systems. It extends the sequential programming language Pascal with concurrent programming tools called processes and monitors. These concepts are explained informally by means of pictures that illustrate a hierarchical design of a simple spooling system. The main contribution of Concurrent Pascal is to extend the monitor concept with an explicit hierarchy of access rights to shared data structures that can be stated in the program text and checked by a compiler.
The Multipurpose Batch Station represents a reduction to practice of a minicomputer system which offers very high performance at very low cost. This acticle demonstrates that well designed software can compensate more...
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The Multipurpose Batch Station represents a reduction to practice of a minicomputer system which offers very high performance at very low cost. This acticle demonstrates that well designed software can compensate more than adequately for primitive hardware - and cost effectively where there are several applications for the developed system. The packing of 1. 5 characters per 12-bit word presents no problem and the searching of tables is circumvented by the technique of executing tables outlined in the text.
Design criteria and methods are presented which simplify the production and modification of software in microprocessor systems. Different strategies are demonstrated on a small real-time system used for recording and ...
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Design criteria and methods are presented which simplify the production and modification of software in microprocessor systems. Different strategies are demonstrated on a small real-time system used for recording and billing phone calls in large office centers, hotels and hospitals. The method chosen makes use of a system table, containing all information related to customer and system configuration, such as language, currency, billing formats, surcharge algorithms. This system table is structured into a number of lists, describing the functions to be carried out. A supervisory program steps through these lists interpreting their contents. The system table is put together at the customers site during installation, avoiding the production of expensive customer software.
This article investigates the dynamics of double-paging, i. e. , running a paged operating system, e. g. , IBM's OS/VS2, under a paged virtual machine monitor, e. g. , VM/370. In particular, it is shown that an in...
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This article investigates the dynamics of double-paging, i. e. , running a paged operating system, e. g. , IBM's OS/VS2, under a paged virtual machine monitor, e. g. , VM/370. In particular, it is shown that an increase in the size of the memory of the virtual machine without a corresponding increase in its real memory size can lead to a significant increase in the amount of paging.
A scheduling algorithm which works with simplified models of all processes and some view of program value to allocate resources to get the best expected usage of the system is suggested. The paper proposes a number of...
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A scheduling algorithm which works with simplified models of all processes and some view of program value to allocate resources to get the best expected usage of the system is suggested. The paper proposes a number of analogies from social allocation strategy. The ideas are highly related to thoughts already circulating in the computer community, particularly for heuristic search and artificial intelligence. The use of heuristics in the form of contracts is most appropriate for two reasons: the allocation of resources need not be optimum, but merely workable and forgiving of error; and the heuristics for each resource are written by the designer of the resource, and turnable by him, to whatever degree of precision he can justify or accomplish.
In a computer system, scheduling occurs whenever the next-task-to-receive-service is selected from a queue of waiting tasks. This paper considers the scheduling of jobs which will become active; that is, which will be...
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In a computer system, scheduling occurs whenever the next-task-to-receive-service is selected from a queue of waiting tasks. This paper considers the scheduling of jobs which will become active; that is, which will begin to compete for use of the system processors. Jobs waiting to be activated may be scheduled by referring to properties of the job such as priority or total resource usage. It is also possible to examine some feature of the jobs already activated in order to determine a suitable candidate for admission to the mix. This is called mix-dependent scheduling. This paper examines some intrinsic property of the jobs rather than an external one. The property chosen to investigate is the rate of processor (CPU or I/O) usage. A hybrid simulation model is used to evaluate a large number of scheduling strategies based on the mix-dependent job scheduling technique.
Consider a program with m statements and n predicates, where the predicates are derived from the conditional statements and assertions in a program. An observable state is an evaluation of the n predicates under some ...
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ISBN:
(纸本)3540291318
Consider a program with m statements and n predicates, where the predicates are derived from the conditional statements and assertions in a program. An observable state is an evaluation of the n predicates under some state at a program statement. The goal of predicate-complete testing (PCT) is to evaluate all the predicates at every program state. That is, we wish to cover every reachable observable state (at most m x 2(n) of them) in a program. PCT coverage subsumes many existing control-flow coverage criteria and is incomparable to path coverage. To support the generation of tests to achieve high PCT coverage, we show how to define an upper bound U and lower bound L to the (unknown) set of reachable observable states R. These bounds are constructed automatically using Boolean (predicate) abstraction over modal transition systems and can be used to guide test generation via symbolic execution. We define a static coverage metric as vertical bar L vertical bar/vertical bar U vertical bar, which measures the ability of the Boolean abstraction to achieve high PCT coverage.
SHE (Software/Hardware Engineering) is a new object-oriented analysis, specification and design method for complex reactive hardware/software systems. SHE is based on the formal specification language POOSL and a desi...
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ISBN:
(纸本)0818682167
SHE (Software/Hardware Engineering) is a new object-oriented analysis, specification and design method for complex reactive hardware/software systems. SHE is based on the formal specification language POOSL and a design framework guiding analysis and design activities This paper reports on the applicability of the SHE method for the specification and design of the control subsystem of a new generation of industrial mailing machines.
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