[jprotocol]

Hello all.

The following lines of code aiming to use a midi synthesizer in order to have it play random notes.
If i use this code routing midi to any hardware port, it works fine.
If i use it to route midi to "Java Software Synthesizer" device, i can only use one (out of 16) midi channels of this device: should i attempt to concurrently use any second (or third) channel, the program breaks, and i am getting the following error:

"Invalid memory access of location 0x22795d32c rip=0x7fffffe00eca"

Please note the lines that start with "new Player".
Commenting all of them (except one), results in sending midi to one channel only - thus, no problem.
Un-commenting two lines, thus evoking a second "player" causes the error.

I tried it on Snow Leopard and on Windows, it gives a similar "invalid memory" error.
I fear that all this trouble has to do with my less-than-perfect knowledge on threading, so i would appreciate any help.

Kind Regards,
Panos





The code:

-----------------------------------------

import java.util.*;
import javax.sound.midi.*;

class Tester {
   public static void main (String[] args) {

	// Discover Connected Midi Devices - Start
	System.out.println("\n");
	System.out.println("List Of Midi Devices Available:");
	System.out.println("-------------------------------");
  	MidiDevice.Info[] mididevices = MidiSystem.getMidiDeviceInfo();
	for (MidiDevice.Info deviceInfo : mididevices)
	{
  		System.out.println("Device Name : " + deviceInfo.getName());
  		System.out.println("Device Description : " + deviceInfo.getDescription() + "\n");
	}
	// Discover Connected Midi Devices - End
	
	    try
	    {
		MidiDevice.Info[] devices = MidiSystem.getMidiDeviceInfo();
		for (MidiDevice.Info deviceInfo : devices) {
		//System.out.println("Name : " + deviceInfo.getName());
		//System.out.println("Vendor : " + deviceInfo.getVendor());
		//System.out.println("Version : " + deviceInfo.getVersion());
	   	//System.out.println("Description : " + deviceInfo.getDescription());
		//System.out.println("\n");
		}

		new Player("4").start();
	    new Player("1").start();
		//new Player("2").start();
		//new Player("3").start();
		}

		catch (Exception e)
   	{
     		System.out.println("Something failed !!!");
   	}	
   }
}

class intRand {
   public static int get (int[] array) {
	Random generator = new Random();
   int rnd = generator.nextInt(array.length);
   return array[rnd];
   }
}

class stringRand {
   public static String get (String[] array) {
	Random generator = new Random();
   int rnd = generator.nextInt(array.length);
   return array[rnd];
   }
}

class Player extends Thread {
   public Player(String str) {
   super(str);
   }
   public void run() {
	String selectedChannel = getName();
		int midiChannel = Integer.parseInt(selectedChannel);

		try
	    {
	    MidiDevice.Info[] infos = MidiSystem.getMidiDeviceInfo();
	    int numInfos = infos.length;
	    MidiDevice.Info deviceInfo = null;
	    for (int i = 0; i < numInfos; i++)
	    {
	      if (infos[i].getName().equals("Java Sound Synthesizer")) { deviceInfo = infos[i]; }
	    }
	    MidiDevice outputDevice =
	    MidiSystem.getMidiDevice(deviceInfo);

	    outputDevice.open();

	    ShortMessage sm = new ShortMessage();
	    Receiver receiver = outputDevice.getReceiver();

	    int sequenceSteps 			= 200;
		int[] selectedNotes 		= { 70 , 80 , 75 , 67 , 51 };
		int[] selectedDurations 	= { 100, 300, 625, 1250, 5000 };
		int[] selectedVelocities 	= { 75 , 85 };
		int[] selectedPauses 		= { 100, 300, 625, 1250, 5000 };

		for (int i = 1; i < sequenceSteps+1; i++)
		{
		int n = intRand.get(selectedNotes);
		int d = intRand.get(selectedDurations);
		int v = intRand.get(selectedVelocities);
		int p = intRand.get(selectedPauses);
		
		// Report
		System.out.println("Midi : " + (midiChannel+1) + ". Step : " + i + ". Note : " + n + ". Duration : " + d + ". Velocity : " + v + ".");

		sm.setMessage(ShortMessage.NOTE_ON, midiChannel, n, v); receiver.send(sm, -1);
	    if (i < sequenceSteps) { Thread.sleep(d); }
		if (i == sequenceSteps) { Thread.sleep(10000); }
	    sm.setMessage(ShortMessage.NOTE_OFF, midiChannel, n, v); receiver.send(sm, -1);
		sleep(p);
		}

	    outputDevice.close();
	    }
	    catch (Exception e)
	    {
	      System.out.println("Something failed !!!");
	    }
   }
}

[jprotocol]

The question has been answered here:

Multiple Midi Channels Problem (Java in General forum at JavaRanch)

[jprotocol]

The question has been answered here:

Multiple Midi Channels Problem (Java in General forum at JavaRanch)