Objectoriented approach to parallel programming on the 'NET platform

1
Object-oriented approach toparallel programming
on the .NET platform

• Polyphonic C an extension of the C with new
  asynchronous concurrency model
• MC a distributed variant of the Polyphonic C
• Examples of programming in MC
• Implementation issues
• Results and problems

2
Polyphonic C an extension of the C with new
asynchronous concurrency constructs

• Nick Benton, Luca Cardelli, Cedric Fournet
  (Microsoft Research Laboratory, Cambridge)
• "Modern Concurrency Abstractions for C" - to
  appear in ACM Transactions on Programming
  Languages and Systems
• http//research.microsoft.com/nick/polyphony

3
Some history

• p - calculus ( R. Milner, 1992 )
• Join-calculus ( C. Fournet, G,Gonthier, 1996 )
• Polyphonic C ( N.Benton, L.Cardelli, C.Fournet,
  2002 )
• Polyphonic C C
• asynchronous methods chords

C
4
Asynchronous model of Polyphonic C

• Asynchronous methods
• async Compute( int n )
• // method body
• Chords
• int Get() async c( int x )
• return ( x )

5
MC a distributed variant of the Polyphonic C

• Movable methods
• movable Compute( int n )
• // method body
• Channels
• int Get() Channel c( int x )
• return ( x )

6
MC a distributed variant of the Polyphonic C

• New modifiers for movable methods
• functional
• non-functional
• global
• Channel types
• movable Compute( int n,
• Channel( int ) c )
• movable Compute( int n,
• Channel( Channel( int ) ) c )

7
Examples of programming in MCn - th Fibonacci
number

• class Fib
• public movable Compute( int n, Channel( int ) c
  )
• if ( n lt 2 ) c( 1 )
• else
• Fib f new Fib()
• Compute( n - 1, f.c1 )
• Compute( n - 2, f.c2 )
• c( f.Get2() )
• int Get2() Channel c1( int x )
• Channel c2( int y )
• return x y

8
Examples of programming in MCn - th Fibonacci
number

• class ComputeFib
• public static void Main( string args )
• int n System.Convert.ToInt32( args 0 )
• ComputeFib cf new ComputeFib()
• Fib fib new Fib()
• fib.Compute( n, cf.c )
• Console.WriteLine( n "-th Fibonacci number
  is
• cf.Get() )
• public int Get() Channel c( int x )
• return x

9
Examples of programming in MCEratosthenes sieve

• Bi-directional channels
• public class BDChannel
• public BDChannel()
• public void Send( params object o )
• public int Receive()

10
Examples of programming in MCEratosthenes sieve

• movable Sieve( BDChannel cin, BDChannel cout )
• int head (int) cin.Receive()
• if ( head -1 )
• cout.Send( -1 )
• else
• cout.Send( head )
• BDChannel inter new BDChannel()
• Sieve( inter, cout )
• filter( head, cin, inter )

11
Implementations issues

• MC - implementation Compiler
  Runtime-system
• Compiler
• translates a program from MC to C
• preparing it for execution under the
  Runtime-system
• Runtime-system
• ResourceManager
• - distributes movable methods over the nodes
• WorkNode
• - starts and controls execution of movable
  methods
• Communicator
• - transfers the channel messages to objects
  located on given node

12
ResultsFibonacci (granule 40)
Configuration All nodes Pentium III 600 MHz x
2, 512 Mb
13
ResultsMandelbrot set
Configuration All nodes Pentium III 600 MHz x
2, 512 Mb
14
ResultsLife game
Configuration All nodes Pentium III 600 MHz x
2, 512 Mb
Fragments 3 100 width 33 height 100 frames
15
Zhukovsky problem
16
Zhukovsky problem
17
Problems

• Memory management in Windows
• Performance of C-programs vs C and
  Fortran-programs
• Serialization performance
• Generics for C
• Maximal number of threads