Differences b/w user level and kernel supported threads, Computer Engineering

Assignment Help:

What are the differences between user level threads and kernel supported threads?

A thread, sometimes termed a lightweight process (LWP), is a fundamental unit of CPU utilization; this comprises a thread ID, a register set, a program counter and a stack.

A thread shares along with other threads belonging to similar process its data section and code section and other operating-system resources, as signals and open files.

If the process has many threads of control, this can do more than one task at a time.

User Level Threads Vs Kernel Supported Threads

i. User threads are supported above the kernel and are implemented through a thread library at the user level.

Here, kernel threads are supported directly through the operating system.

ii. For user threads, the thread library gives support for thread creation, scheduling and management within user space with no support from the kernel as the kernel is unaware of user-level threads. In case of kernel threads, the kernel does thread creation, scheduling and management inside kernel space.

iii. As there is no require of kernel intervention, user-level threads are usually fast to create and manage it. As thread management is made by the operating system, kernel threads are usually slower to create and manage which is a user thread.

iv. Any user-level thread performing blocking system call, if the kernel is single-threaded, will cause the whole process to block, even if other threads are available to run inside the application.

Though, as the kernel is managing the kernel threads, whether a thread performs a blocking system call, the kernel can schedule the other thread in the application for execution.

v. User-thread libraries contain POSIX P threads, Mach C-threads and Solaris 2 UI-threads.

Several of the cotemporary operating systems which support kernel threads are Windows NT, Windows 2000, Solaris 2, BeOS and Tru64 UNIX (formerly Digital UNIX).


Related Discussions:- Differences b/w user level and kernel supported threads

Convert ascii code to its bcd equivalent, Convert ASCII code to its BCD equ...

Convert ASCII code to its BCD equivalent. This can be achieved by simply replacing bits in upper four bits of byte by four zeros. For illustration the ASCII '1' is 32h = 0010B. By

Find minimal expression for sop, Consider the following expression. Assume ...

Consider the following expression. Assume that complement inputs are available. F(A,B,C,D) = ∑m (0,1,3,5,9,12,14) + ∑d (4,10,15) 1. Find minimal expression for SOP. Draw gate ne

Illustrate associative memory, Q. Illustrate Associative Memory? The ti...

Q. Illustrate Associative Memory? The time required to find an item which is stored in memory can be decreased significantly if stored data can be identified for access by cont

What is a single stage network, In a single stage network: (A) ...

In a single stage network: (A)  There is no redundancy (B)  There is redundancy (C)  Alternative cross points are available (D)  Alt

Linux, Explain about unix file system architecture

Explain about unix file system architecture

What is cyclomatic complexity, What is cyclomatic complexity? Cyclomati...

What is cyclomatic complexity? Cyclomatic complexity is a computer science metric (measurement) developed by Thomas McCabe used to generally calculate the complexity of a progr

Explain call completion rate in telephone traffic, With reference to teleph...

With reference to telephone traffic, explain the terms CCR. CCR: Call completion rate is explained as the ratio of the number of successful calls to the number of call attemp

Define the three prime processes of UML, Define the three prime processes o...

Define the three prime processes of uml The three prime processes were OMT (Rumbaugh), OOSE (Jacobson) and Booch. OMT was strong in analysis, while Booch was strong in design a

Show the characteristic of cache memory, Q. Show the characteristic of cach...

Q. Show the characteristic of cache memory? The essential characteristic of cache memory is its fast access time. So very little or no time should be wasted when searching for

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd