Explain the life cycle of a process, Computer Engineering

Explain the life cycle of a process

Each procedure has a life cycle, which consists of execution, creation and termination phases of the procedure.  A method may create several new procedures, which in turn may also generate still new processes, using system calls. In UNIX operating system environment, a new procedure is produced by fork system call. Process creation needs the following four actions:

i) Setting up the process description: Setting up the process description needs the creation of a Process Control Block (PCB). A  Process Control Block contains basic data such as owner, process identification number, process status, explanation of the allocated address space and other completion dependent process specific information needed for procedure management.

ii)   Allocating an address space:  There are only  two ways to allocate address space to processes; allocating separate space to each process or distribution the address space among the created processes.

iii) loading the program into the allocated address space: The executable program file is overloaded into the allocated memory space.

iv)  Passing the process description to the process scheduler:  The process created is then conceded to the process scheduler who distributes the processor to the competing processes.

The process implementation phase is controlled by the process scheduler. Process scheduling may be per process or per thread. The process scheduling involves three concepts: process states, state transition diagram and scheduling policy.

A process may be in one of the following states given below:

  • New: The process is being formed.
  • Running: The process is being implemented on a single or multiple processors.
  • Waiting: The process is to come for some event to occur.
  • Ready: The process is prepared to be implemented if a processor is available.
  • Terminated: The process has completed execution.

At any time a procedure may be in any single of the above said states. As soon as the process is announce into the job line, it goes into equipped state. When the process scheduler transmits the process, its state turn into running. When the process is completely implemented then it is completed and we say that it is in the completed state. However, the process may return to ready state due to some type of interruption or may go to in waiting state because of some I/O activity. When I/O activity is finished it may go to ready state. The state transition diagram shown in figure 3:

                                2250_life cycle of a process.png

The scheduling policy may be both non pre-emptive and pre-emptive. In pre-emptive policy, the process may be distructed. OS had dissimilar scheduling policies. One of the common policies is First In First Out (FIFO) to select the process to be implemented. When the process finished implementation it is terminated by system calls like abort.

Posted Date: 3/1/2013 5:56:58 AM | Location : United States







Related Discussions:- Explain the life cycle of a process, Assignment Help, Ask Question on Explain the life cycle of a process, Get Answer, Expert's Help, Explain the life cycle of a process Discussions

Write discussion on Explain the life cycle of a process
Your posts are moderated
Related Questions
Why IO devices cannot be directly be connected to the system bus? The IO devices cannot be directly linked to the system bus because i.  The data transfer rate of IO device

Explain about the network security. Network security implies the protection of networks and their services through unauthorized access, destruction or disclosure, modificati

What are the characteristics of SRAM? SRAM are fast They are volatile They are of high cost Less density

Explain how SAP GUI handles output screen for the user. The SAP front-end s/w can either run on the similar computer or on dissimilar computers given for that purpose.  User t

Even while Generalization satisfies Structural, Interface, Behaviour properties. It is mathematically very strong, as it is Antisymmetric and Transitive. Antisymmetric: employe

What is critical section problem?  Consider a system having of 'n' processes. Each process has segment of code known as a critical section, in which the process may be changing

A Scrollbar is a Component, but not a Container while Scrollpane is a Container and handles its own events and do its own scrolling.

Example Multi-layer ANN with Sigmoid Units: However we will concern ourselves here that with ANNs containing only one hidden layer and as this makes describing the backpropaga

Final Animation This is the final piece of work that should stand on its own as a piece of Art or Design. This is your personal response to the idea of Transformation - The pro

In a DTMF phone a dialling of 8 generates (A) 1336 Hz- 770 Hz                      (B)  1209 Hz - 1477 Hz (C)  1209 Hz- 941 Hz                     (D)  1336 Hz-852 Hz