org.jcsp.lang

Class AltingChannelInput<T>

java.lang.Object

org.jcsp.lang.Guard

org.jcsp.lang.AltingChannelInput<T>

All Implemented Interfaces:

ChannelInput<T>, Poisonable

Direct Known Subclasses:

AltingChannelInputWrapper, RejectableAltingChannelInput

public abstract class AltingChannelInput<T>
extends Guard
implements ChannelInput<T>

This extends Guard and ChannelInput to enable a process to choose between many object input (and other) events.

A reading-end, obtained from a one-one or any-one channel by invoking its in() method, will extend this abstract class.

Description

AltingChannelInput extends Guard and ChannelInput to enable a process to choose between many object input (and other) events. The methods inherited from Guard are of no concern to users of this package.

Example

 import org.jcsp.lang.*;
 
 public class AltingExample implements CSProcess {
 
   private final AltingChannelInput in0, in1;
   
   public AltingExample (final AltingChannelInput in0,
                         final AltingChannelInput in1) {
     this.in0 = in0;
     this.in1 = in1;
   }
 
   public void run () {
 
     final Guard[] altChans = {in0, in1};
     final Alternative alt = new Alternative (altChans);
 
     while (true) {
       switch (alt.select ()) {
         case 0:
           System.out.println ("in0 read " + in0.read ());
         break;
         case 1:
           System.out.println ("in1 read " + in1.read ());
         break;
       }
     }
 
   }
 
 }
 

Author:

P.D. Austin and P.H. Welch

See Also:

Guard, Alternative

Constructor Summary

Constructors

Constructor and Description
AltingChannelInput()

Method Summary

Modifier and Type	Method and Description
abstract boolean	pending() Returns whether there is data pending on this channel.

Methods inherited from class org.jcsp.lang.Guard

schedule

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jcsp.lang.ChannelInput

endRead, read, startRead

Methods inherited from interface org.jcsp.lang.Poisonable

poison

Constructor Detail

AltingChannelInput

public AltingChannelInput()

Method Detail

pending

public abstract boolean pending()

Returns whether there is data pending on this channel.

Note: if there is, it won't go away until you read it. But if there isn't, there may be some by the time you check the result of this method.

Returns:

state of the channel.