Chapter 3 Process Management ( Concepts (Process control block (Process…
It's a program in execution
Includes the current activity and the contents of the processor registers
Process control block
CPU scheduling information
Memory management information
I/O status information
A thread of instructions being executed
Select processes from this pool and loads them into memory for execution
Switching the CPU to another process requires performing a state save of the current process and a state restore of a different process.
Operation on Process
A process may create several new processes. Each of these new processes may in turn create other processes, forming a tree of processes.
Most OS identify processes according to a unique process identifier.
A process terminates when it finishes executing its final statement and asks the OS to delete it by using the exit() system call.
A process can cause the termination of another process via an appropriate system call (TerminateProcess() in Windows)
Shared Memory System
Multiple processes can access a space in memory to communicate with other process
Message Passing Systems
A process can send direct messages to another process
Communication in Client-Server Systems
A pair of processes communicating over a network employs a pair of sockets
Uses a client-server architecture
Remove a procedure calls
Each message is addressed to an RPC daemon listening to a port on the remote system, and each contains an identifier specifying the function to execute and the parameters
The producer writes to one end of the pipe and the consumer reads from the other end
Communication can be bidirectional
Several processes can use it for communication
Daniela Porras Quirós