Skip to main content

Operation on processes

Operation on processes

                                                                                                                                                                                                                                                                                     

1. create a process

2. destroy a process 

3. suspend a process

4. resume a process 

5. change the priority of a process

6. block a process 

7. wake up a process

8. dispatch a process

9. enable inter process communication 

All operation on a process are explain following:

1. create a process:Operation on a Process:

The execution of a process is a complex activity. It involves various operations. Following are the operations that are performed while execution of a process:

1. Creation: This the initial step of process execution activity. Process creation means the construction of a new process for the execution. This might be performed by system, user or old process itself. There are several events that leads to the process creation. Some of the such events are following:

  • When we start the computer, system creates several background processes.
  • A user may request to create a new process.
  • A process can create a new process itself while executing.
  • Batch system takes initiation of a batch job.

2. Scheduling/Dispatching: The event or activity in which the state of the process is changed from ready to running. It means the operating system puts the process from ready state into the running state. Dispatching is done by operating system when the resources are free or the process has higher priority than the ongoing process. There are various other cases in which the process in running state is preempted and process in ready state is dispatched by the operating system.

3. Blocking: When a process invokes an input-output system call that blocks the process and operating system put in block mode. Block mode is basically a mode where process waits for input-output. Hence on the demand of process itself, operating system blocks the process and dispatches another process to the processor. Hence, in process blocking operation, the operating system puts the process in ‘waiting’ state.

4. Preemption: When a timeout occurs that means the process hadn’t been terminated in the allotted time interval and next process is ready to execute, then the operating system preempts the process. This operation is only valid where CPU scheduling supports preemption. Basically this happens in priority scheduling where on the incoming of high priority process the ongoing process is preempted. Hence, in process preemption operation, the operating system puts the process in ‘ready’ state.

5. Termination: Process termination is the activity of ending the process. In other words, process termination is the relaxation of computer resources taken by the process for the execution. Like creation, in termination also there may be several events that may lead to the process termination. Some of them are:



                     

Comments

Post a Comment

Popular posts from this blog

Layered Operating System

  Layered Operating System Layered Structure is a type of system structure in which the different services of the  operating system  are split into various layers, where each layer has a specific well-defined task to perform . It was created to improve the pre-existing structures like the Monolithic structure ( UNIX ) and the Simple structure ( MS-DOS ). Example –  The Windows NT operating system uses this layered approach as a part of it . Design Analysis : The whole Operating System is separated into several layers ( from 0 to n ) as the diagram shows. Each of the layers must have its own specific function to perform. There are some rules in the implementation of the layers as follows. The outermost layer must be the User Interface layer. The innermost layer must be the Hardware layer. A particular layer can access all the layers present below it but it cannot access the layers present above it. That is layer n-1 can access all the layers from n-2 to 0 but it canno...
Post a Comment
Read more

OS its Resource Manager and its Function

  Operating system as resource manager:   ·           A computer system usually has many hardware and software resources such as processor , memory, disk printer, I/O devices etc. ·           The task of resources management becomes essential in multi-user operating system where different user compute for the same resource.   Operating system manages resources in two ways : 1.         Time multiplexing : it defines the sharing of resources on the basis of fixed time slices. For example, the operating system allocate the resources, such as CPUto program A for fixed time slice. 2.         Space timing:  it defines the concurrent sharing of resources among different programs.for example, sharing of hard disk and main memory is space multiplexing.     FUNCTION OF OPERATING SYSTEM     The primar...
2 comments
Read more

Monolithic Architecture

  Monolithic Architecture Monolith means composed all in one piece. The  Monolithic  application describes a single-tiered  software  application in which different components combined into a single program from a single platform. Components can be: Authorization — responsible for authorizing a user Presentation — responsible for handling HTTP requests and responding with either HTML or JSON/XML (for web services APIs). Business logic — the application’s business logic. Database layer — data access objects responsible for accessing the database. Application integration — integration with other services (e.g. via messaging or REST API). Or integration with any other Data sources. Notification module — responsible for sending email notifications whenever needed. Example for Monolithic Approach Consider an example of Ecommerce application, that authorizes customer, takes an order, check products inventory, authorize payment and ships ordered products. This applicat...
Post a Comment
Read more

Suspend a process

  Suspend a process A process is an active program. It can also be said as a program that is under execution. It is more than the program code as it includes the program counter, process stack, registers, program code etc. Compared to this, the program code is only the text section. A process passes through different states as it executes. These states may be different in different operating systems. However, the common process states are explained below with the help of a diagram − New This is the state when the process has just been created. It is the initial state in the process life cycle. Ready In the ready state, the process is waiting to be assigned the processor by the short term scheduler, so it can run. This state is immediately after the new state for the process. Ready Suspended The processes in ready suspended state are in secondary memory. They were initially in the ready state in main memory but lack of memory forced them to be suspended and gets placed in the second...
Post a Comment
Read more

Scheduler

  Scheduler   Scheduling Objectives Here, are important objectives of Process scheduling Maximize the number of interactive users within acceptable response times. Achieve a balance between response and utilization. Avoid indefinite postponement and enforce priorities. It also should give reference to the processes holding the key resources  Process Scheduling handles the selection of a process for the processor on the basis of a scheduling algorithm and also the removal of a process from the processor. It is an important part of multiprogramming in operating system. Process scheduling involves short-term scheduling, medium-term scheduling and long-term scheduling. Details about these are given as follows − Long-Term Scheduling Long-term scheduling involves selecting the processes from the storage pool in the secondary memory and loading them into the ready queue in the main memory for execution. This is handled by the long-term scheduler or job scheduler. The long-term s...
Post a Comment
Read more