Swapping is one of the several methods of memory management. In swapping an idle or a blocked process in the main memory is swapped out to the backing store (disk) and the process that is ready for execution in the disk, is swapped in main memory for execution. We will be discussing swapping in more detail. As we all know, a process must be placed in main memory for its … [Read more...] about Swapping in Operating System
Memory Allocation
Memory allocation is an action of assigning the physical or the virtual memory address space to a process (its instructions and data). The two fundamental methods of memory allocation are static and dynamic memory allocation. The static memory allocation method assigns the memory to a process, before its execution. On the other hand, the dynamic memory allocation method … [Read more...] about Memory Allocation
Directory Structure
Several users create thousands and millions of files in a file system. To organize these files properly file system uses directory structure. The directory structure has the entries of the all the files related to that directory. We can consider that a directory is a file, that contains information about the other files. Here, we will discuss some common schemes defining the … [Read more...] about Directory Structure
Process Control Block (PCB)
For each process, the operating system maintains the data structure, which keeps the complete information about that process. This record or data structure is called Process Control Block (PCB). Whenever a user creates a process, the operating system creates the corresponding PCB for that process. These PCBs of the processes are stored in the memory that is reserved for the … [Read more...] about Process Control Block (PCB)
Multithreading Models in Operating System
Multithreading Models in Operating System exhibit the ways of mapping the user threads to the kernel threads. Here, we will learn about the three multithreading models, Many to One model, One to One model and Many to Many model. Many to One multithreading model maps many user threads to only one kernel thread. One to One multithreading model maps a single user thread to a … [Read more...] about Multithreading Models in Operating System
Shared Memory System in IPC
Shared memory system is one of the fundamental models of interprocess communication. In the shared memory system, the cooperating processes communicate with each other by establishing the shared memory region, in its address space. Shared memory model allows the fastest interprocess communication. Among the cooperating processes, the process that wants to initiate the … [Read more...] about Shared Memory System in IPC
First Come First Serve (FCFS) Scheduling Algorithm
First Come First Serve (FCFS) is a CPU scheduling algorithm where the process that arrives first in the ready queue will be served first by the CPU. FCFS is a non-preemptive scheduling algorithm i.e. once the CPU is allocated to a process, the process releases the CPU only when the process gets terminated or it requests for I/O. FCFS is a Batch System algorithm in which the … [Read more...] about First Come First Serve (FCFS) Scheduling Algorithm