A task is an abstract unit of work whose meaning changes with the level of discussion. It can refer to a process thread, a function call within a thread, or a running program managed by an operating system. section 10.5
The term commonly shifts between these contexts:
- Within a process, a task is one of its threads. section 10.5
- Within a thread, a task may be a function call. section 10.5
- At the operating-system level, a task may be a running program. section 10.5
Task virtualization also involves isolation. Isolated tasks cannot freely interfere with one another, access one another’s data, or cause failures to cascade, although stronger isolation brings greater overhead and limits communication. section 10.5
Figure 10.5 Trade-offs relating to different forms of task isolation in computing. In general terms, increasing the isolation level increases the overhead.
Compare forms of task isolation and observe the general trade-off between increasing isolation and increasing overhead. section 10.5
