To understand system calls, first one needs to understand the difference between kernel mode and user mode of a CPU. Every modern operating system supports these two modes. In computing, a system call is the programmatic way in which a computer program requests a service from the kernel of the operating system it is executed on. A system… Read More »
Transport Layer is the second layer of the TCP/IP model. It is an end-to-end layer used to deliver messages to a host. It is termed as an end-to-end layer because it provides a point-to-point connection rather than hop-to- hop, between the source host and destination host to deliver the services reliably. The unit of data encapsulation in Transport… Read More »
C++ is a cross-platform language that can be used to create high-performance applications. C++ gives programmers a high level of control over system resources and memory. C++ was developed by Bjarne Stroustrup, as an extension to the C language. Language designers: Bjarne Stroustrup Language paradigms: Object-oriented program. There are various published Versions of C++ : C++98, C++03, C++11,… Read More »
Deadlock Detection and Deadlock recovery are important tasks of OS. If deadlocks are not avoided, then another approach is to detect when they have occurred and recover somehow. These are explained as following below. 1. Deadlock Detection : If resources have single instance : If cycle exist in the Resource Allocation Graph, then there exist deadlock in the… Read More »
A scheduler is a type of system software that allows you to handle process scheduling. There are mainly three types of Process Schedulers: Long Term, Short Term, Medium Term. These are explained as following below. Long Term or job scheduler : Long term scheduler is also known as job scheduler. It chooses the processes from the pool (secondary… Read More »
A network consists of two or more nodes (e.g. computers) that are linked in order to share resources (such as printers and CDs), exchange files, or allow electronic communications. The computers on a network may be linked through cables, telephone lines, radio waves, satellites, or infrared light beams. Networking Elements : The computer network includes the following networking… Read More »
Process Synchronization is a way to coordinate processes that use shared data. Critical section is a segment of code that can be accessed by only one signal process at a certain instance in time. This section consists of shared data resources that need to be accessed by other processes. The entry to the critical section is handled by… Read More »
Dual-mode operation forms the basis for I/O protection, memory protection and CPU protection. Two modes are provided by the hardware – user and kernel mode. Mode bit is added to computer hardware to indicate the current mode. When system boots, hardware starts in kernel mode. The OS is loaded and then user process is started in user mode.… Read More »
The Operating system (OS) acts as a host for application programs that are run on the machine. Operating system (OS) is a software which acts as an interface between the end user and computer hardware. Every computer must have at least one OS to run other programs. In simple terms, an operating system is the interface between the… Read More »
Network Topology is the representation of a network arrangement, consisting of several nodes i.e. sender and receiver nodes, and the lines connecting these nodes. Types of Network Topology : Let us look at the type of Network Topologies available. P2P Topology : Point-to-point topology is the easiest of all the network topologies. In this method, the network consists… Read More »
