Skip to main content

Multi threading operating system

 


Multi threading 

operating system

·         Multi threading is a technique in which a process, executing an application is divided into threads that can run concurrently

·         A thread is a dispatch able unit of work. It includes  a processor context and its own data area for sack .

·         A thread execute sequentially and is interruptible so that the processor can turn to another thread.

·         Thus, a thread represents a light weight process and is the smallest unit of CPU utilization it is like a mini process.

·         A process, on other hand is a collection of one or more threads and associated system resources

·         A thread is not a process by itself. Cannot run on its own. It always run within a process.

·         Thus, a multithreaded process may have multiple execution flows, different once belonging to difficult threads.

 

Multi Threading Operating 

System

A thread is not a process by itself .it cannot run on its own. It always run within a process

 



 

The various States exhibited by windows thread are:

1.       Ready. A ready thread may be scheduling for execution. The kernel dispatcher keeps track of all ready threads and schedules them in priority order.

2.       Standby. A thread that has been selected to run next on a particular processor is said to be in standby state. The thread waits in this state until the processor is made available.

3.       Running the thread that is currently CPU is in running state.it keeps the processor until it is preempted by a higher priority thread or it gets blocked or its time slice expires.

4.       Waiting. A thread enters waiting state when:

(a)    It is blocked on event .

(b)   It voluntarily waits for synchronization purpose.

(c)    An environment subsystem directs the thread to suspend itself.

When waiting condition is satisfied, the thread moves back to ready state if all the resource are available.

5.       Transition. A thread enters this state after waiting if it is ready to run but resources are not available.

6.       Terminated. A thread can be terminated by itself, by another thread or when its parent process terminates.

Comments

Popular posts from this blog

Defination of OS(operating system) and its concepts

    What do you mean by operating system?     Definition :  An operating system is a program that act as an interface between the user of a computer and the                                      Computer hardware. Operating system is a first program that gets loaded into the memory through a process called booting. Concepts of operating system : ·                       The purpose of operating system is to provide an environment in which a user can execute program in a convenient and efficient manner. ·                       Operating system is an integrated set of program that ma...

Process Termination or destroy a process

  Process Termination or destroy a process Processes may request their own termination by making the  exit( )  system call, typically returning an int. This int is passed along to the parent if it is doing a  wait( ) , and is typically zero on successful completion and some non-zero code in the event of problems. child code: int exitCode; exit( exitCode ); // return exitCode; has the same effect when executed from main( ) parent code: pid_t pid; int status pid = wait( &status ); // pid indicates which child exited. exitCode in low-order bits of status // macros can test the high-order bits of status for why it stopped Processes may also be terminated by the system for a variety of reasons, including: The inability of the system to deliver necessary system resources. In response to a KILL command, or other un handled process interrupt. A parent may kill its children if the task a...

Multi processing system

  Multi processing system ·           Multi processesor system is the sytem that contain two or more processors or CPUS and has ability to simultaneously execute     several programs. Hence the name multi-processor In such a system, multiple processor share the clock, bus, memory and peripheral devices. ·           A multi processor system is also known as parallel system ·           Multi processor system are categorized into two different types:                single user operating system    2.        Multi user operating system   3.         Batch processing operating system 4.        Multi programming operating system   5.       Multi tasking operating sy...

Multi Programming Operating System

  Multi programming  system ·           Multi programming operating system allows multiple users to execute multiple programs using a single CPU concurrently i.e. at the same time. ·           In multiprogramming several process are kept in the main memory and CPU execute all these processes concurrently. It means, the CPU immediately switches from one process to next that are ready to get executed ·           In such an operating system when one process start process start performing the instructions from several programs at the same time. ·           Rather, it means that there are number program available to CPU and that portion of one is executed, then segment of another and so on                                 ...

Micro kernel architecture

  Micro kernel  architecture What is Kernel? A kernel is an important part of an OS that manages system resources. It also acts as a bridge between the software and hardware of the computer. It is one of the first program which is loaded on start-up after the bootloader. The Kernel is also responsible for offering secure access to the machine's hardware for various programs. It also decides when and how long a certain application uses specific hardware. What is Microkernel? Microkernel  is a software or code which contains the required minimum amount of functions, data, and features to implement an operating system. It provides a minimal number of mechanisms, which is good enough to run the most basic functions of an operating system. It allows other parts of the operating system to be implemented as it does not impose a lot of policies. Microkernels and their user environments are usually implemented in the C++ or C programming languages with a little bit of assembly. Ho...