Week 3 Flashcards
-a program in execution; process execution must progress in sequential fashion. No parallel execution of instructions of a single process.
process
(process concept)
-the program code
text section
(process concept)
-containing temporary data
-function parameters, return addresses, local variables
stack
(process concept)
-containing global variables
data section
(process concept)
-containing memory dynamically allocated during run time
heap
(process concept)
-program is this entity stored on disk (executable file); active
passive entity
(process state)
-the process is being created
new
(process state)
-instructions are being executed
running
(process state)
-the process is waiting for some event to occur.
waiting
(process state)
-the process is waiting to be assigned to a processor
ready
(process state)
-the process has finished execution
terminated
(process control block)
-information associated with each process
task control block
(process control block)
-running, waiting, etc.
process state
(process control block)
-location of instruction to next execute.
program counter
(process control block)
-contents of all process-centric registers
CPU registers
(process control block)
-priorities, scheduling queue pointrs
CPU scheduling information
(process control block)
-memory allocated to the process
memory-management information
(process control block)
-CPU used, clock time elapsed since start, time limits.
accounting information
(process control block)
-I/O devices allocated to process, list of open files
I/O status information
-consider having multiple program counters per process.
–multiple locations can execute at once
-must then have storage for thread details, multiple program counters in PCB.
threads
