First UNIX system was developed in 1969 and ran on systems from microprocessors to mainframes and provided a common execution environment across them. The system was divided into two parts : Programs and services: It is the part readily apparent to users e.g. shell, mail text editor etc. Operating System: That supports above-mentioned programs and service. […]
We can achieve this by isAlive() and join() methods of Thread class. isAlive() is not great at doing this task. So, we will be using join() method. Threadd class — implements Runnable : class Threadd implements Runnable{Thread t;String name; Threadd(){name = “how”;t = new Thread(this,name);System.out.println(“This is thread”);t.start();} public void run() {for(int i=0;i<20;i++){System.out.println(“This is run method”);try{Thread.sleep(100);}catch(InterruptedException […]
While passing arguments, the function creates copies of the arguments passed to it. This type of passing arguments is called passing by value. We can pass structure as arguments. We can also return a structure. Useful while returning multiple values. Passing by reference : e.g. void intfunc(float& a, int& b); We can also pass structures […]
Initializing structure structure_name variable_name = {value1,value2,…,valueN}; Initializing nested structure structure_name variable_name = { {value1, value2},{value3,value4}}; A structure can be nested up to any depth in theory. Structure can hold data and functions (In c they can only hold data) An enum declaration defines the set of all names that will be permissible values of the […]
Overview : UNIX : Layered Architecture Linux : Monolithic Architecture Windows : Hybrid Architecture (Microkernel + Layered) Mach : Microkernel Architecture. UNIX KERNEL ARCHITECTURE : Unix OS considers files and processes as the most important entities. Unix offers a shell that acts as a command interpreter between the user and the kernel. The relevant […]
Virtualization can be defined as the process of creating multiple copies of an object. A virtual machine is a virtualization of a machine. The software that creates multiple copies of a machine is called a virtual machine monitor (VMM) or a hypervisor. Each virtual machine have its own OS called ‘guest OS’ and the OS […]
There are mainly three types of operating system architecture models : Monolithic OS : Used in older but smaller operating systems. Operating system is divided into procedures. Each procedure have a particular task and all procedures have common data structures and system tables. Each procedure can call other procedures. Resulting in high degree of inter-process […]
There are mainly three types of OS architecture models : Monolithic OS Layered OS Client-server or microkernel OS In every model, there are two modes of processor execution : the user mode and the system mode. Application programs run in the user mode whereas the operating system runs in the system mode. The system mode […]
Before C++ true and false were represented as 1 and 0 respectively. But C++ uses both. Other than 0 all values represent true. Library function exit() : exit(0) : Normal Exit exit(other numerical value) : Error / Abnormal exit. This function is present in ‘process.h’ Library function getche(): This function is present in conio.h No […]
White-space is completely ignored by compiler : Not True. There are few restrictions apply to this rule. e.g. Preprocessor directives must be in same line. ‘cout’ could not be broken. Cout, Cin are objects : These are overloaded. Cout – ‘<<‘ (Put to or insertion operation) and ‘>>’ (extraction or get operator). Directives : Preprocessor […]