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This module describes the basics of Microsoft Visual Basic Threads and Semaphores.


Microsoft Visual Basic provides resources for managing threads and semaphores. This module will give a basic overview of threads and semaphores in Visual Basic (VB). This module presents threads and semaphores in VB in a very simplistic manner. There are much better ways to use threads in VB but they will be presented here in a way that makes the programs much easier to write. The threads described here will be methods of the Form class. This is what makes the programming very simple. Threads should/could be classes on their own but it is not necessary. This module is not intended to make you proficient in using threads and semaphores in Visual Basic.


Module prerequisites

It would be helpful to have completed the TSK and SEM modules for the DSP/BIOS operating system but it is not necessary if you are familiar with tasks and semaphores.

Visual basic threads

A thread is simply a separate method or function that gets executed apart from the main program flow. There can be many threads executing simultaneously in a system. In VB the System.Threading namespace needs to be imported into the program. This is done by putting the following at the very top of your code:

Imports System.Threading

If this is not included at the top of your program then it will not know what threads are.

The following is the basic structure of your program for this lab. Each part of the example code is described in the comments.

' This imports the threading namespace so the program knows about threads Imports System.Threading' This is the class that executes the form for the programPublic Class Form1 ' This is a definition of a thread. The thread object is thread1 and' it uses the method Task1() below as its code. Dim thread1 As New Thread(AddressOf Task1)' When the form program starts or is loaded the following function is' called. This is where you can put the commands to set up our program. ' The code for starting up the threads can be put here.Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load' Make this a background thread so it automatically ' aborts when the main program stops.thread1.IsBackground = True ' Set the thread prioritythread1.Priority = ThreadPriority.Lowest ' This command starts the thread. The method Task1() then' starts to execute. thread1.Start()End SubPrivate Sub Task1() ' This is where your code goes for this threadEnd SubEnd Class

The real-time operating system in Visual Studio is not a deterministic operating system. This means that you cannot be sure of how the threads will execute. Windows assigns time to threads at the same priority in a round-robin fashion. When threads at a particular level do not need to execute the operating system assigns time to lower priority threads.

Questions & Answers

Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Ti dsp/bios lab. OpenStax CNX. Sep 03, 2013 Download for free at http://cnx.org/content/col11265/1.8
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