Browse Prior Art Database

Service Management

IP.com Disclosure Number: IPCOM000080469D
Original Publication Date: 1973-Dec-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 5 page(s) / 45K

Publishing Venue

IBM

Related People

Aken, BR: AUTHOR [+2]

Abstract

A new category of facilities, termed Service Management, has been incorporated into VS2 Release 2. These facilities provide a basic set of system services which allow internal system components to structure themselves to run enabled, nonserialized and in parallel on a relocate-MP system with considerably less overhead than would be required by the utilization of existing task management services. The facilities provided are the following:

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Service Management

A new category of facilities, termed Service Management, has been incorporated into VS2 Release 2. These facilities provide a basic set of system services which allow internal system components to structure themselves to run enabled, nonserialized and in parallel on a relocate-MP system with considerably less overhead than would be required by the utilization of existing task management services. The facilities provided are the following:

1. A new, high performance dispatching function for system service requests has been provided which operates off a new control structure. The control structure is such that it facilitates ease in scheduling services to be performed, provides a very simple technique for scheduling work in different virtual memories, and allows system services to operate either at priorities which are independent of the virtual memory priority associated with each user, or at a specific memory priority.

2. A very simple form of an "ATTACH"-like service has been provided, which allows new service requests to be entered into the queue of dispatchable work with a minimal amount of overhead.

3. A new control block, termed a Service Request Block (SRB), approximately 44 bytes in size, has been defined to represent a service request. This is a significant size reduction over the current Task Control Block/Request Block (TCB/RB) control block definitions, and will result in both a real storage savings and a reduction in the amount of information that must be initialized for each request.

These facilities are only available to supervisor state system services and their presence will be transparent to problem program tasks. Service Request Processing.

The basic facilities provided by Service Management are those services required to:

1. Introduce a request to execute a specific service routine into the queue of work within the system.

2. Perform priority dispatching of services.

3. Support the needs of recovery/termination for the cleanup of the asynchronous processes.

The introduction of a service request into the queue of work is accomplished via the SCHEDULE macro. This is a non-Supervisor Call (SVC) macro service and the interface to it requires that the invoker supply.

1. A previously obtained and formatted service request block (SRB) to represent the request until it is actually dispatched. The contents of the SRB supplied define the attributes of the routine to be given control and the SRB itself must be fixed in commonly addressable storage with a system protect key. The

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specific information contained within the SRB is the following. a) The address of the Address Space Control Block (ASCB) representing the address space that this service request is to be dispatched in. b) The protect key that the routine will run with. c) The entry point address of the routine to be given control. d) The address of a resource manager termination routine. e) The address of a status save area. Normally...