2.1.6 Implementation of Processes
To implement the process model, the operating system maintains a table (an
array of structures) called the process table, with one entry per process.
(some authors call these entries process control blocks.) The entry contains
information about the process' state, it's program counter, stack pointer
memory allocation, the status of its open files, its accounting and scheduling
information, alarms and other signals, and everything else about the process
that must be saved when the process is switched from running to ready state
so that it can be restarted later as it has never been stopped.
In MINIX 3, interprocess communication, memory management and file management
are each handled by separate modules within the system, so the process table
is partitioned, with each module maintaining the fields that it needs. Figure
2-4 shows some of the more important fields.
[Figure 2-4 delar upp det i tre tabeller, "Kernel", "Process management" och
"file management"]