Skip to main content

Atomic Transaction In Operating System


All the synchronization techniques we have studied are essentially low level as like semaphores. They require the programmer to involved with all the details of mutual exclusion, critical region management, deadlock prevention, and crash recovery. An abstraction exists there  and is widely used in distributed systems. We will call it an atomic transaction, or simply transaction.


 The term atomic action is also widely used. The mutual exclusion of critical section ensures that the critical sections are executed automatically. That is, if two critical sections are executed concurrently, the result is equivalent to their sequential execution in some unknown order.


  In many cases we would like to make sure that a critical section forms a single logical unit of work that either is performed in its entirely or is not performed at all. An example is funds transfer, in which one account is debited and another is credited. Clearly, it is essential for data consistency either that both the credit and debit occur or that neither occur.


A collection of instructions or operations that performs a single logical function is called transection. A major issue in processing transaction is the preservation of automicity despit the the possiblity of failures within the computer system. When a transaction starts executing, its first action is to execute wait() or down(). After the transaction either commits or abort , it executes signal() or up(). Although this scheme ensures that atomicity of all concurrently executing transactions, it is neverthless too restrictive.


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

Comments

Popular posts from this blog

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 ...

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...

Definition of Stack and its algorithm with working process(data structure)

                  Stack                           A Stack is  an ordered collection of items where the addition of items and the removal of existing items always takes place at the same end. This end is commonly referred to as the “top". * working method of stack :- i> Initially top=-1 ii> By increasing top pointer we can insert element    in the stack. iii> when top=size of stack-1  then stack is full. iv> By decreasing the top pointer we can remove   the   element from stack. v> when top=-1 then the stack is empty. figure shows run time stack * The fundamental operations which are possible on a stack are:-         1. push operation (insertion).    2. pop operation (deletion).    3. peep opetation(extract informat...