The Process StructureIn addition to the references to the substructures, the process entry shown in Figure 4.1 contains the following categories of information: • Process identification: the PID and the parent PID • Signal state: signals pending delivery and summary of signal actions• Tracing: process tracing information• Timers: real-time timer and CPU-utilization counters  The process substruc..

3.3 Traps and InterruptsTraps, like system calls, occur synchronously for a process. Traps normally occur because of unintentional errors, such as division by zero or indirection through an invalid pointer. The process becomes aware of the problem either by catching a signal or by being terminated. Traps can also occur because of a page fault, in which case the system makes the page available an..