Shallow Dive: Parallel Fx

Alex MooreSoftware Developer, TDCI

No More Free Lunch

Processors not getting much faster

No More Free Lunch

transistors++

No More Free Lunch

transistors++ speed++

No More Free Lunch

transistors++ speed++

No More Free Lunch

transistors++ speed++

cores++

Elephant in the Room

Elephant in the Room

Parallel / Concurrent Programming is about to reach it’s boiling point

Elephant in the Room

Can’t ignore it much longer

Elephant in the Room

There will be language, library, and tool support for this soon.

There will be language, library, tool, and hardware support for this soon.Concurrency is one of the main themes for C# 4.0, the PFX will probably be part of .Net 4.0, Visual Studio 2010 will have tools to help better debug concurrent programs, and Intel’s next Core processor, the i7, will have a whole slew of improvements to help run concurrent and threaded applications better.

Parallel Extensions to the .Net Framework

PLINQ

Task Parallel Library

Scheduler

System.Threading

CDS

How to Express Parallelism

How to Express Parallelism

Threading sucks

How to Express Parallelism

Declarative data parallelism - PLINQ

How to Express Parallelism

Declarative data parallelism - PLINQ

Imperative data parallelism - Parallel.For

How to Express Parallelism

Declarative data parallelism - PLINQ

Imperative data parallelism - Parallel.For

Imperative task parallelism - Tasks, Futures

PLINQ

from x in setwhere x == somevalueselect expensiveFunction(x);

PLINQ

from x in setwhere x == somevalueselect expensiveFunction(x);

from x in set.AsParallel()where x == somevalueselect expensiveFunction(x);

Parallel.For

for( int i = 0; i < 10; i++ ){ ... }

Parallel.For

for( int i = 0; i < 10; i++ ){ ... }

Parallel.For( 0, 10, i => { ... } );

Parallel.ForEach

foreach( var x in set ) { ... }

Parallel.ForEach

foreach( var x in set ) { ... }

Parallel.ForEach( set, x => {...});

Tasks

A();B();C();

Do_Something();

Tasks

Task t1 = Task.Create( ()=> A(); );Task t2 = Task.Create( ()=> B(); );Task t3 = Task.Create( ()=> C(); );

Task.WaitAll(t1, t2, t3);

Do_Something();

Futures

var a = A();var b = B();var c = C();

Do_Something(a,b,c);

Futures

var a = Future.Create( ()=> A(); );var b = Future.Create( ()=> B(); );var c = Future.Create( ()=> C(); );

Do_Something(a,b,c);

Demos

Box of Sharp Knives

PFX is a big box of sharp knives. Yes they are shiny and you want to grab them but be careful.

Box of Sharp Knives

★Not a silver bullet for performance

This should not be your first choice for improving performance. Clean “responsible” design will go a long way when optimizing code, and will help when deciding where to apply concurrency.

Box of Sharp Knives

★Not a silver bullet for performance

✓Get the CTP

✓Read, Do, and Learn

This should not be your first choice for improving performance. Clean “responsible” design will go a long way when optimizing code, and will help when deciding where to apply concurrency.

Questions?Comments ?

Are there any questions ? Comments ?

How to find info

• MSDN Magazine - October ‘08

• Channel 9 - “Parallel Extensions”

• Blogs: Joe Duffy, Herb Sutter

• http://geekswithblogs.net/alexmoore/archive/2008/10/22/parallel-extensions-links.aspx

Thanks!

Alex Moore

Blog: geekswithblogs.net/alexmoore

Twitter: @alexmoore