jcsp.plugNplay
Class Plex

java.lang.Object
  |
  +--jcsp.plugNplay.Plex

All Implemented Interfaces:

CSProcess

public final class Plex

extends Object

implements CSProcess

Fair multiplexes its input Object stream array into one output stream.

Process Diagram

     in[0] +------+
    ------>|      |
       :   |      | out
       :   | Plex |----->
   in[n-1] |      |
    ------>|      |
           +------+
 

Description

Plex 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
in[]	java.lang.Object	The input streams.
Output Channels
out	java.lang.Object	The multiplexed output stream.

Example

The following example shows how to use Plex in a small program.

 import jcsp.lang.*;
 import jcsp.plugNplay.*;
 
 public final class PlexExample {
 
   public static void main (String[] argv) {
 
     final One2OneChannel[] a = One2OneChannel.create (3);
     final One2OneChannel[] b = One2OneChannel.create (3);
     final One2OneChannel c = new One2OneChannel ();
 
     new Parallel (
       new CSProcess[] {
         new Numbers (a[0]),
         new Fibonacci (a[1]),
         new Squares (a[2]),
         new Sign ("Numbers ", a[0], b[0]),
         new Sign ("            Fibonacci ", a[1], b[1]),
         new Sign ("                          Squares ", a[2], b[2]),
         new Plex (b, c),
         new Printer (c, "", "\n")
       }
     ).run ();
 
   }
 
 }
 

Implemntation Note

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

   public void run () {
     Alternative alt = new Alternative (in);       // in is the input channel array
     while (true) {
       out.write (in[alt.fairSelect ()].read ());  // out is the output channel
     }
   }
 

Author:

P.H.Welch

See Also:

Plex2, Multiplex

Constructor Summary

Plex(AltingChannelInput[] in, ChannelOutput out)
Construct a new Plex process with input channels in and output channel out.

Method Summary

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

Plex

public Plex(AltingChannelInput[] in,
            ChannelOutput out)

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

Parameters:

in - the input channels

out - the output channel

Method Detail

run

public void run()

The main body of this process.

Specified by:

run in interface CSProcess