Dynamic association of input/output device with application programs

• US 6,473,824 B1
• Filed: 10/12/1999
• Issued: 10/29/2002
• Est. Priority Date: 10/14/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Stegerer, Armin, Kreissig, Gerald, Kreissig, Astrid
• Primary Examiner(s): Ray, Gopal C.
• Application Number:
  US09/416,834
• Time in Patent Office: 1,113 Days
• Field of Search: 710/6, 710/305, 710/8-11, 710/18, 710/19, 710/104, 710/105, 713/100, 709/321, 709/316, 709/301, 709/302, 709/220, 709/328, 712/220
• US Class Current: 348/222.1
• CPC Class Codes: G06F 13/102 where the programme performs an interfacing function, e.g. device driver G06F13/105 takes precedence; scheduling within device drivers G06F9/52; contention policies within device drivers G06F9/4881

Abstract

An object-oriented framework is introduced for coupling device drivers to an application program. Two class trees are introduced: the first class tree comprises the device drivers. The device drivers actually exchange messages with the IO devices. They depend on the protocol used, on the IO interface, and on the operating system. The second class tree comprises the so-called physical objects. Their task is to define parameters that are necessary to describe what an IO device is supposed to do. The parameters only depend on the device'"'"'s functionality, but not on the protocol, the IO interface or the operating system. In order to couple a physical object with a device driver, the physical object holds a pointer to its device driver. The connection is an “object reference,” and therefore, the active device driver may be changed at runtime.

Claims

1. An object-oriented framework in memory of a computer system, said framework providing a communication path between an application program and IO devices attached to said computer system, each IO device being connected to a certain IO interface and utilizing a certain IO protocol for exchanging messages with said computer system, said framework comprising:

a first class tree comprising a set of physical objects,

said physical objects defining parameters for data exchange with the application program, said parameters being independent of the IO device'"'"'s IO protocol and of the IO interface the IO device is attached to,

a second class tree comprising a set of IO device drivers,

said IO device drivers being designed for a certain IO interface and a certain IO protocol, and said IO device drivers being capable of exchanging messages in said IO protocol via said IO interface with the IO device attached to said IO interface, and

means for establishing and changing an object reference between any of said physical objects and any of said device drivers at runtime, whereby said physical object maintains a pointer to its corresponding device driver.

2. An object-oriented framework according to claim 1, said framework further comprising a resource file specifying the IO devices attached to the computer system and the IO device driver required for each IO device.

3. An object-oriented framework according to claim 1 or claim 2, said framework further comprising a configurator object, for providing, after having obtained a physical object'"'"'s logical address, said physical object with a pointer to the corresponding IO device driver and with the physical address of the IO device that said physical object is supposed to control.

4. A computer-implemented method for establishing a communication path between an application program and an Input/Output (IO) device that is attached to a computer system, said IO device being connected to a certain IO interface and utilizing a certain IO protocol for exchanging messages with said computer system, said method comprising the steps of:

instantiating a physical object from a first class tree comprising a set of physical objects, said physical object being instantiated based on functionality information about said IO device;

instantiating an IO device driver from a second class tree comprising a set of IO device drivers, said IO device driver being instantiated based on IO interface information and IO protocol information about said IO device; and

establishing an object reference between said physical object and said IO device driver at runtime, whereby said physical object maintains a pointer to said IO device driver.

5. A method for establishing a communication path according to claim 4 wherein said step of establishing an object reference between said physical object and said device driver comprising the steps of:

forwarding said physical object'"'"'s logical address from said physical object to a configurator object; and

returning, from said configurator object to said physical object, a pointer to said IO device driver and a physical address of said IO device that said physical object is supposed to control.