Browse Prior Art Database

Method for Controlling Virtual Terminal to an Activity

IP.com Disclosure Number: IPCOM000062102D
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Baker, DC: AUTHOR [+4]

Abstract

A method is described to prevent unnecessary and unpredictable allocation and reclamation of virtual terminals in a multiple interactive task environment. Standard UNIX*-type processes manipulate the file descriptors (opening and closing), which in many cases are attached to a terminal which was previously a physical terminal. With the addition of multiple virtual terminals, a virtual terminal is reclaimed when all file descriptors accessing the virtual terminal are closed. If the process opens a terminal, a new virtual terminal is allocated. This causes two problems: one, the user may see terminals "flash" on the screen as they are opened and closed, and the second is that the activity manager loses the association of a particular terminal to a task and hiding, activating, etc., are unable to take place.

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

Page 1 of 1

Method for Controlling Virtual Terminal to an Activity

A method is described to prevent unnecessary and unpredictable allocation and reclamation of virtual terminals in a multiple interactive task environment. Standard UNIX*-type processes manipulate the file descriptors (opening and closing), which in many cases are attached to a terminal which was previously a physical terminal. With the addition of multiple virtual terminals, a virtual terminal is reclaimed when all file descriptors accessing the virtual terminal are closed. If the process opens a terminal, a new virtual terminal is allocated. This causes two problems: one, the user may see terminals "flash" on the screen as they are opened and closed, and the second is that the activity manager loses the association of a particular terminal to a task and hiding, activating, etc., are unable to take place. According to the new method, a process is added as a "place holder" to keep the tasks terminal open during file descriptor manipulation. Further, since most tasks are unaware that they are executing in a multiple interactive task environment, the task does nothing explicit to notify the system of its termination when an execute thread ends. The user may therefore be unaware of the termination of an activity or of its creation. Since there are multiple activities, the activity manager cannot "wait" for each thread like the shell. With the new method, for each interactive execution thread, a "monitor" process...