This articles is 1st part of the 5 part series which gives overview of the Parallel Processing in Visual Studio 2010.
The .net framework 4.0 introduces a new programming
architecture for doing multiple processes asynchronously that greatly
simplifies the application load and gets better performance. The new programming architecture helps
developers to write a scalable and more efficient code in order to achieve
better performance for the application development. Parallel LINQ (PLINQ) which
is a parallel implementation of LINQ to Objects enables similar functionality
for the developers through declarative coding.
You can have in your mind how multi core processor is
related with multi threaded application. The concept would be like application
development processes based on the environment the application is running. Even
though the application runs in multi core processor, fewer resources will be
taken by the application to run the process. Say for example multi core
processor has the ability to handle n number of process; code will work step by
step in any one of the processor leaving remain processor unused. Now the developers
can make use of this particularly when working on complex algorithms or in case
of need to handle multiple processes asynchronously.
Multi threaded programming is one of the way which gives
developers an option to work with multiple threads concurrently. Even though
this concept is been available since .net 1.1, its been avoided due to the
complexity and developers need to write clean code in order to get performance
using Multi threaded concept rather spending most of the time with business and
Using Normal Process
Consider a real time example of a web page having a Tab
Control, as per the normal programming each tab will be loaded sequentially as
per the business and not in parallel. Definitely it takes more time to load the
contents to different tabs from each data source.
Using Parallel Process
Normal processing uses only a single processor even though
the other processors are idle over there. But when using parallel processing
(using Parallel Library) the other processors are also used to execute the core
functionality which gives application a much performance.
Finally Multi Threaded application works on both multi core
and also on a single core processor as it’s based on the hardware
configuration. Underneath the code will be working on the single thread if it
goes to a single processor and multiple threads if it goes to a multi
Concurrent Processing vs Parallel Processing
In Concurrent programming several streams of functionality
may be executed concurrently. Each one of the functionality operated in a
sequential order process except that it communicate and interfere with one
another. For Example: Two thread tasks Task1 and Task2 are concurrent if the
order in which the tasks are executed is not predetermined. The possible
execution is as follows.
- Task1 may be executed and completed before Task2
- Task2 may be executed and completed before Task1
- Task1 and Task2 may need to be executed alternatively
- Task1 and Task2 may be executed and completed simultaneously
at the same time period (Parallelism)
In parallel Programming, it’s the process of executing the
functionality by dividing into sub functionalities that are to be operated as
concurrent programs. For Example: If two concurrent thread tasks are scheduled
to run by OS and if these threads run on a single core processor we will get
concurrency if the same is running on a multi core processor we will get
So we can't say which is more efficient programming that the
other, but neither is the superset of the other programming process. Based on
the business requirement the processor can be selected and used in the
application development process.
Parallel Programming Architecture
Figure – Reference from http://msdn.microsoft.com/en-us/library/dd460693%28VS.100%29.aspx
Above architecture diagram explains in detail on how the
parallel processing will takes and gets scheduled based on the needs. The main
components of this architecture are as follow.
Task Parallel Library
Parallel LINQ (PLINQ)
Lambda Expressions in PLINQ
We will get into detail of each component and see how the
process takes place in each component in the next upcoming article.