Processes Flashcards
what is a program
a set of instruction
what is a process
a program together with its files and metadata
what is context
information about each process, held in memory.
the environment in which a process operates, including variables and resources.
what is an address space
the accessible memory locations for a process
what is segmentation
memory is divided into variable sized chunks
where does the OS hold the information about a process
process control block
what is init
the root of the hierarchy of processes in linux
what does it mean for a process to fork
create a clone of itself- its child.
what is an orphan? what happens to the child?
the parent expires before the child.
the child is adopted by init and becomes a daemon
what is a zombie
a child process terminated unnoticed by its parent
give the elements that make up a process’ context
variables and resources in memory
registers storing:
state
memory management page tables
list of resources the process owns
cached information
what is multiprocessing? what need does it create?
multiprocessing is a resource
it creates a need to communicate between processes
how can processes communicate
shared memory
files
message passing
signals
pipes
barriers
how is IPC performed using shared memory
there will be a shared byte where one process can write if it is on and the other can read etc.
it is safe and atomic. May require locks and semaphores
how is IPC preformed using files
processes alter the file contents
