process management in operating system

     process management  in operating system

process management :

 process can be thought of as a program in execution process will need certain resource such as CPU time memory files and IO device to accomplish if this resource is elected to the process either when it is a created or while it is executing.

  process is the unit of work in most system Campton sister selection of process execute 16 code execute user code executes currently is it the unit work in the modern time-sharing system.

 process management is an integral part of any modern-day operating system do OS must allocate process management resource to the process enables the process to share and exchange information the resource of each the process from other process and enable synchronization among process to meet this requirement is must maintain the data structure for each process which describe the research ownership of that process and which enable the OS to accept control over state and Research ownership.

1. Two state process management :

 the operating systems principle responsibility is in controlling the execution of process this include determining the interview pattern for execution and allocation of resources to process 1 part of designing and Overseas to describe the behavior that we would like each the process to exhibit the simplest model is    bass  on the fact that a process is either being executed by a processor it does not do a process maybe considered to be in 1 of 2 state running aur not running is placed into a queue in the system in the not running state the process main memory and its weights in the queue for an opportunity.

 after some period of time the currently running process will interact and movers the running state to the not running state making the process available for different process the dispatch quotation of the will then select from the cube or not running process process transfer the process the process is then reliability from not running state to a running state and it is exhibition is either being it is a new process.

 2.Three state process management :

   Two  state management model is perfectly Valley design for an open system the absence of a blocked state means that the process lies  when the active process changes from the CPU cycle design does not make efficient use of the  processor the three-state process management model is designed to overcome this problem by introducing a new state called the block state describe any process which is waiting for an event to take place in this case and event means the use of some device for a single from another process does three states are at any instant a process is in one and only one of the three states for a single process Computer only can be in the running state at any one instant there can be many processes in the ready and blocked state and each of these state will behave associated queue for the process process entering the system must go initially  the system from the running state for each of the three states the the process occupies space in many memory while the reason for most one state to another might be obviously some may not be so clear

 3.five state process management model :

 while the three-state model is sufficient to describe the behavior of process with the given events we have a extend the model to allow for the other possible event and FOMO particular the use of the potential of the hard disc unit main memory National state to describe the state of a process which is suspended from the main memory and place in virtual memory process can at a feature time be resumed by being transferred back into main memory the medium level control this event a process can be suspended from the running ready for blocked state given rise to other states namely ready suspend a running process that is suspended become can be suspended for a member of the reason the most significant of which arise from the process being swept out of memory by the memory management system in order to free memory for other processes other common reason for a process being suspended is when one suspended exhibition debugging a program or when the system is monitoring process for the five-step process management model consists of the following the transaction described in the next section.