Several useful software engineering techniques, disciplines and perspectives are related to typical software development problems in design automation. Specific examples from recent experience illustrate both benefici...
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Several useful software engineering techniques, disciplines and perspectives are related to typical software development problems in design automation. Specific examples from recent experience illustrate both beneficial and undesirable practices. Oriented toward managers and practicing software engineers, the tutorial discusses system structure, control and data structures, programming guidelines, work habits, testing, documentation and operational maintenance.
An operating system control program must create and maintain a record of each resource in a computer system allocated to a user, including information on the restrictions/limits on that allocation. In order to safegua...
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An operating system control program must create and maintain a record of each resource in a computer system allocated to a user, including information on the restrictions/limits on that allocation. In order to safeguard system security/integrity, the resource record must be maintained in a control block or group of control blocks that are protected, i. e. , cannot be changed by the user. A control block structure/validity-checking mechanism is described that provides the necessary verification when the user program is allowed to supply a privileged control program routine with the address of a single protected control block that records his allocation to a particular resource.
A monitor program is described which provides a statement usage count that can be used to ″tune″ the monitored program and to provide an aid to debugging. The monitor is written in PL/I.
A monitor program is described which provides a statement usage count that can be used to ″tune″ the monitored program and to provide an aid to debugging. The monitor is written in PL/I.
The multiprocessor system described consists of many basic processors (BP) with memory, all of which can access the shared unit through a single bus. The functions performed are returned to each BP by a separate singl...
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The multiprocessor system described consists of many basic processors (BP) with memory, all of which can access the shared unit through a single bus. The functions performed are returned to each BP by a separate single bus. The access control mechanism forms the main body of this description.
Instruction handling in a stored program computer system is speeded up by eliminating unnecessary storage accesses during execution of branch and jump instruction and thereby provides performance improvement. This spe...
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Instruction handling in a stored program computer system is speeded up by eliminating unnecessary storage accesses during execution of branch and jump instruction and thereby provides performance improvement. This speedup is achieved in a computer system where instructions are fetched a byte at a time.
The emerging technology of distributed computing, and the growing trend of computerization of large systems necessitates a technique for distributed and cooperative authorization and control. For example, a large fina...
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The emerging technology of distributed computing, and the growing trend of computerization of large systems necessitates a technique for distributed and cooperative authorization and control. For example, a large financial transaction in a distributed electronic-fund transfer (EFT) system may require the independent approval of several subjects. An authorization scheme which can support such a cooperation is described, based on the operation-control scheme recently developed by the author.
A mass storage system (MSS) services a plurality of hosts under the general supervision of a primary host. Each MSS includes a mass storage control (MSC);a staging adapter director (DIRSA), which serves as a port for ...
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A mass storage system (MSS) services a plurality of hosts under the general supervision of a primary host. Each MSS includes a mass storage control (MSC);a staging adapter director (DIRSA), which serves as a port for transferring data signals between any of the hosts;and a disk staging data storage facility (DSF). Further, the data bases are stored on tape cartridges in a mass storage facility (MSF) having a multiplicity of cartridge sotrage cells, which are movable to data recording devices for recording and reproducing data signals to exchange them with the DSF. MSC controls the interchange of data signals under the indicated control lines and keys an inventory table of contents of the stored data signals, plus the location of each cartridge in MSF. Programs are described that enable automatic means for inventorying MSF for ensuring data integrity.
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