Skip to main content

Process Synchronization & Race Condition

  
    ⇰  SYNCHRONIZATION :-

 Process Synchronization is simply a way to coordinate processes that share something or use shared data. Synchronization occurs in an operating system among cooperating processes. Before starting the brief discuss we have to know types of processes.
  There are two types of process according to sharing :-
i>  Independent process.
ii> Coordinate process.

 i>  Independent process :- Those process which do not share anything to other processes is called Independent process. Execution of one process will not affect other process.

ii> Coordinate process :- Those process which share something with other processes as common variable, memory, code or resources(cpu, printer). So execution of a particular process can affect other process. And cooperative process is not properly synchronised, that can create problem as data inconsistancy.

  While executing many cooperative processes, process synchronization helps to maintain shared data consistency and cooperating process execution. Processes have to be synchronized to ensure that concurrent access to shared data or anything does not create inconsistency. Let us see a problem:-
 Consider two peocesses P1 and P2 running on some system at same time. Let there is a common variable 'shared'.
sleep(1) :- This code is used to switch Between processes.

Execution of Processes will bs as follows:- 
Hence shared=4, which is wrong because in execution of P1 & P2, X++ and Y-- emplies the same as 5++ =>6 and 6-- => 5. 
This situation arrised because P1 & P2 are not synchronized.
      ⇰  RACE CONDITION :-

 When data is not consistent the situation is called race condition. A race condition occurs when two or more porcesses execute at the same time, without synchronized in the proper sequence. As we can see in our above example when we start execution of P1 first than P2, we get shared=4 and id we start P2 first than P1 we get shared-6. But both are wrong because shared must equal to 5.

    The situation like this, where several processes access and manipulate the same data concurrently and outcome of the execution depends upon particular order in which access takes place is called as race condition. 

 click here for critical section

 Share, Follow and please comment if you find anything incorrect or to share more information about the topic discussed above


Labels:

Comments

Post a Comment

Please comment.

Popular posts from this blog

Process Scheduling And Types of Process Schedular :-

        ⇰ PROCESS SCHEDULING Process Scheduling  is a task  of Operating System that schedules processes of different states like new, ready, waiting, terminated  and running.This scheduling helps in allocation of CPU time for each process, and Operating System allocates the CPU time for each procss. And the process scheduling plays important role to keep the CPU busy all the time.  ⏩   Followings are some objectives of Process Scheduling :-  i > To increase the amount of users within acceptable response times.  ii > To maintain the balance between response and utilization of system. iii > To decrease the enforce priorities and  give reference to the processes holding the key resources.      ⇰  PROCESS SCHEDULAR A scheduler carries out the pro cess scheduling work. Schedulers are often implemented so they keep all computer resources busy and  allows multiple users to shar...
8 comments
Read more

Process & Its state And process control block :-

                ⇰  PROCESS :- A process can be thought of as a program in execution. Means when any program is executed it becomes process. A processwill need certain resources such as CPU time , memory, files and I/O devices to complete its task. These resources are allocated to the process either when it is created or at the time of execution.             A process is the unit of work in most systems. A system consistes of a collection of processes. All these processes may execute concurrently. Traditionally a process contained only a single thread. Most modern operating ststems now supports processes that have multiple threads.         The operating system is responsible for several important works of process management as - the creation and deletion of process, the schrduling of process, communication and deadlock handling of process. Process is broudly divided into two ...
Post a Comment
Read more

Tokens and its types in 'C'

   Tokens are the smallest individual unit of a program or in simple words it is a main part of C program.Tokens are the building blocks of any program. The smallest individual and basic unit of a C programming is called c tokens.      *    Normally there are six types of tokens in C:- i> Keywords:-          Keywords are special words that are used to give a special meaning to the program and can't be used as variable and constant.They are basically a sequence of characters that have fixed to mean. For example:-                 auto     double      long     break                 float    short        char     if                while    continue   int       void etc. All...
3 comments
Read more