Equivalent of Go Channel in Java: Multiplexing Source Data

To handle the situation where multiple BlockingQueues require monitoring but without creating multiple reader threads, a mechanism similar to Go's channel and select is valuable. In Java, the JCSP library offers a functional equivalent.

JCSP Alternative: A Go Select Counterpart

The JCSP Alternative is equivalent to Go's select statement. It allows a consuming thread to switch on multiple input channels without having to poll them. This ensures efficient multiplexing of source data, avoiding unnecessary loops even when some queues have no data.

JCSP Implementation

An example of using JCSP's Alternative for fair multiplexing of input channels is provided below:

import org.jcsp.lang.*;

public class FairPlex implements CSProcess {

   private final AltingChannelInput[] in;
   private final ChannelOutput out;

   public FairPlex (final AltingChannelInput[] in, final ChannelOutput out) {
     this.in = in;
     this.out = out;
   }

   public void run () {

     final Alternative alt = new Alternative (in);

     while (true) {
       final int index = alt.fairSelect ();
       out.write (in[index].read ());
     }
   }
 }

Deadlock Avoidance

Similar to Go, Java programs using channels must be carefully designed to avoid deadlocks. The JCSP library's formal analysis validates its channel and Alternative implementation, ensuring reliability and freedom from deadlocks.

Note

The latest stable release of JCSP is version 1.1-rc5, not the version mentioned on the website.