Author Archives: Sachin Kumar

General Overview Of UNIX System

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.

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Ensure Main Method Exit at the End

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

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Things to note about Structure in C plus plus (C++)

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

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Virtual Machine Architecture

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

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Processor Execution Modes

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

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