The independent process in a process family is called the job for that family. The dependent processes in a process family are referred to as tasks.
Note that, in some older publications, you might find the term task used with a different meaning than the one defined here. In addition to the meaning given here, task has sometimes been used to refer to any process, to the offspring of some particular process, or to any discrete unit of work. These usages are generally avoided in this guide, except in the terms task attribute and task variable, which have been retained because they are well known. (More properly, these terms would be process attribute and process variable because they can apply to either jobs or tasks.)
Certain services that the system provides for a process family are linked to the job for the family. The job provides the following services:
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Job logging
The job has a job file associated with it that stores the job log. The job log includes information about the activities of all the processes in the process family. When the job terminates, the system can issue a printout of the job log, called the job summary. (The job file for a WFL job includes additional information, which is described under Special Types of Jobs later in this section.)
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Printer output
By default, any printer backup files created by process family members are saved until the job terminates. The system groups these files into a single entry in the print queue, unless the files have incompatible print attributes, such as different DESTINATION values. For further information about print requests, refer to the Print System User’s Guide.
Operators or programmers can use the following means to determine whether a process is a job or a task:
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Process messages
The system displays a “BOJ” message when a job is initiated and an “EOJ” message when the job is terminated. For a task, the corresponding messages are “BOT” and “EOT.”
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Job displays
The J (Job and Task Display) system command displays all the process families that currently exist. The members of each process family appear in hierarchical order, beginning with the job.
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Job number
A task has a job number that differs from the mix number and indicates the job or session associated with the task. For a job, the job number and mix number are equal. The operator can see the job number and mix number in the output of many system commands. A process can also read these values from the JOBNUMBER and MIXNUMBER task attributes.
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Process type
A process can determine whether a particular process is a job by reading the TYPE task attribute. For WFL jobs, the value is JOBSTACK; for other jobs, the value is RUN. For tasks, the value is CALL or PROCESS.
