Each successful login into a project creates a new task that contains the
login process. The task is a process collective that represents a set of
work over time. A task can also be viewed as a workload component.
Each task is automatically assigned a task ID.
Each process is a member of one task, and each task is
associated with one project.
Figure 2-1 Project and Task Tree
All operations on process groups, such as signal delivery, are also supported on
tasks. You can also bind a task to a processor set and set a
scheduling priority and class for a task, which modifies all current and subsequent
processes in the task.
A task is created whenever a project is joined. The following actions, commands,
and functions create tasks:
You can create a finalized task by using one of the following
methods. All further attempts to create new tasks will fail.
You can use the newtask command with the -F option.
You can set the task.final attribute on a project in the project naming service database. All tasks created in that project by setproject have the TASK_FINAL flag.
For more information, see the login(1), newtask(1), cron(1M), su(1M), and setproject(3PROJECT) man pages.
The extended accounting facility can provide accounting data for processes. The data is
aggregated at the task level.