org.jcsp.plugNplay.ints

Class Plex2Int

java.lang.Object

org.jcsp.plugNplay.ints.Plex2Int

All Implemented Interfaces:

CSProcess

public final class Plex2Int
extends java.lang.Object
implements CSProcess

Fair multiplexes two integer streams into one.

Process Diagram

    in0  __________
   -->--|          | out
    in1 | Plex2Int |-->--
   -->--|__________|
 

Description

Plex2Int is a process whose output stream is a fair multiplexing of its input streams. It makes no assumptions about the traffic patterns occuring on the input streams and ensures that no input stream will be starved by busy siblings. It guarantees that if an input stream has data pending, no other stream will be serviced twice before that data is serviced.

Channel Protocols

Input Channels
in0, in1	int	The input streams.
Output Channels
out	int	The multiplexed output stream.

Example

The following example shows how to use Plex2Int in a small program. The program also uses some of the other plugNplay processes.

 import org.jcsp.lang.*;
 import org.jcsp.plugNplay.ints.*;
 
 public class Plex2IntExample {
 
   public static void main (String[] argv) {
 
     final One2OneChannelInt a = Channel.one2oneInt ();
     final One2OneChannelInt b = Channel.one2oneInt ();
     final One2OneChannelInt c = Channel.one2oneInt ();
 
     new Parallel (
       new CSProcess[] {
         new FibonacciInt (a.out ()),
         new SquaresInt (b.out ()),
         new Plex2Int (a.in (), b.in (), c.out ()),
         new PrinterInt (c.in (), "--> ", "\n")
       }
     ).run ();
 
   }
 
 }
 

Note: this example does not produce easily understandable output, since the multiplexed stream contains only numbers -- there is no indication of the streams from which they were sourced. To get that indication, we can either use MultiplexInt or sign each int stream to be multiplexed with SignInt and multiplex with Plex2.

Implemntation Note

For information, here is the run method for this process:

   public void run () {
     AltingChannelInputInt[] input = {in0, in1};      // in0 and in1 are the input channels
     Alternative alt = new Alternative (input);
     while (true) {
       out.write (input[alt.fairSelect ()].read ());  // out is the output channel
     }
   }
 

Author:

P.H. Welch

See Also:

PlexInt, MultiplexInt

Constructor Summary

Constructors

Constructor and Description
Plex2Int(AltingChannelInputInt in0, AltingChannelInputInt in1, ChannelOutputInt out) Construct a new Plex2Int process with the input channels in0 and in1 and the output channel out.

Method Summary

Modifier and Type	Method and Description
void	run() The main body of this process.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Plex2Int

public Plex2Int(AltingChannelInputInt in0,
                AltingChannelInputInt in1,
                ChannelOutputInt out)

Construct a new Plex2Int process with the input channels in0 and in1 and the output channel out. The ordering of the input channels makes no difference to the behaviour of this process.

Parameters:

in0 - an input channel

in1 - an input channel

out - the output channel

Method Detail

run

public void run()

The main body of this process.

Specified by:

run in interface CSProcess