The way the system is built from components and their relationship is
determined by the architecture of the operating system. Each operating
system is going to be a bit different in the kind of work that it can handle,
and
its organizational structure, so learning this and how to put it all
together can be important.
Process And Flow Management
As we mentioned, one of the most important functions of OS is to execute
applications. Code and application data is stored in the computer cybernetic
system on disk in a special executable manner. After the user decides to run
either OS to perform a file system creates
the basic unit of a computer,
called a
process . You can specify the following: a process is a program that
executes it.
The operating system allocates resources between processes. These
resources include CPU time, memory, devices, disk space as files. For the
allocation of memory of each process, undertake its
address space - set
address memory, which allows you access. The
process space is stored in
the address space. The allocation of disk space for each process formed a
list of open files similarly.
The processes protect the resources they possess. For example, the process
address space cannot be accessed directly from other processes (it is
secure), and when working with files, a mode can be specified that denies
access to the file to all processes except the current one .
The allocation of processor time between processes is necessary because
the processor executes instructions one by one (ie, at a particular time, only
one process can physically execute on it), and for the user,
the processes
should appear as sequences of instructions executed in parallel. To achieve
this effect, the OS provides the processor with each process for a short time,
after which it switches the processor to another process; in this case, the
execution of the processes resume from
the place where they were
interrupted. In a
multiprocessor system, processes can run in parallel on
different processors.
Modern operating systems in addition to processes can support
multitasking,
which provides in the process, the presence of several
sequences of instructions (
threads), which run in parallel to the user, like
most processes in the OS. Unlike processes, threads do not provide resource
protection (for example, they share the address space of their process).
