Browse Prior Art Database

Method for Sharing Hardware Resources among Device Drivers

IP.com Disclosure Number: IPCOM000117451D
Original Publication Date: 1996-Feb-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Doyle, RP: AUTHOR [+3]

Abstract

Disclosed is a method allowing two or more device drivers to share hardware resources. This method is particularly desirable when a system includes a number of device drivers which are frequently idle.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 87% of the total text.

Method for Sharing Hardware Resources among Device Drivers

      Disclosed is a method allowing two or more device drivers to
share hardware resources.  This method is particularly desirable when
a system includes a number of device drivers which are frequently
idle.

      Conventionally, when an application first accesses hardware
devices, a set of hardware resources is allocated to the device
driver by the Hardware Resource Manager (HRM).  If a resource
required by the device driver is being used by another hardware
device, the HRM fails to allocate the requested resource so that the
device driver requesting a resource cannot be loaded.

      According to the presently-disclosed method, a device driver
requesting a resource must implement a relinquish interface.  When a
second device driver requests a resource owned by the first device
driver, the HRM sends a relinquish request to the first device
driver, using the relinquish interface of the first device driver.
At this point, if the first device driver decides that it is idle, or
that it can give up the resource, it turns the resource back to the
HRM with a successful return code.  Otherwise, the resource-owning
device driver rejects the relinquish request by returning a
non-successful return code.  Thus, based on the return call, the HRM
either reallocates the resource to the requesting device driver, or
fails to reallocate the resource.

      If the device driver which relinquished the resource...