Yannick Assogba

I am experiencing what may be a memory leak when creating JitterMatrix objects, consider the following code

private int[]testArr = new int[200 * 200];

private BufferedImage outTestBuf = new BufferedImage(200,200, BufferedImage.TYPE_BYTE_BINARY);

//create a BufferedImage from the array    

outTestBuf.setRGB(0, 0, 200, 200, testArr, 0, 200);

//turn it into a jitter matrix and output it        

JitterMatrix outTest = new JitterMatrix(outTestBuf);

outlet(0, "jit_matrix", outTest.getName());    

testArr is randomly filled with values for black and white upon construction of the object. The method testOutput() is called from the bang() method. When i connect a metro (or qmetro) to the mxj object and run it, the amount of memory max uses starts growing quite fast, and max very soon crashes.

Even when i comment out the line that copies the array into the BufferedImage and use the no argument constructor for Jittermatrix, the memory use still grows continually (albeit much more slowly).

Any help would be much appreciated, i am running this on max 4.5.7 and jitter 1.5.2 on Max OSX and was using the activity monitor to see the memory usage of max.

Another related question is whether what i am doing is the best way to convert an array into a matrix? I am fairly new to the jitter/java api and didn't see anything to directly copy an array into a matrix and thus i took the buffered image route. I also use a buffered image as an intermediary in converting input matrices into arrays for processing.

private int[]testArr = new int[200 * 200];
private BufferedImage outTestBuf = new BufferedImage(200,200, BufferedImage.TYPE_BYTE_BINARY);

  //create a BufferedImage from the array	
  outTestBuf.setRGB(0, 0, 200, 200, testArr, 0, 200);
  //turn it into a jitter matrix and output it		
  JitterMatrix outTest = new JitterMatrix(outTestBuf);
  outlet(0, "jit_matrix", outTest.getName());	

testArr is randomly filled with values for black and white upon construction of the object. The method testOutput() is called from the bang() method. When i connect a metro (or qmetro) to the mxj object and run it, the amount of memory max uses starts growing quite fast, and max very soon crashes.  

Even when i comment out the line that copies the array into the BufferedImage and use the no argument constructor for Jittermatrix, the memory use still grows continually (albeit much more slowly). 

memory-issues-with-jittermatrix

On Jul 10, 2006, at 1:27 PM, Yannick Assogba wrote:

> I am experiencing what may be a memory leak when creating 

> JitterMatrix objects, consider the following code

> private int[]testArr = new int[200 * 200];

> private BufferedImage outTestBuf = new BufferedImage(200,200, 

> //create a BufferedImage from the array    

> outTestBuf.setRGB(0, 0, 200, 200, testArr, 0, 200);

> //turn it into a jitter matrix and output it        

> JitterMatrix outTest = new JitterMatrix(outTestBuf);

> outlet(0, "jit_matrix", outTest.getName());    

This is because Java doesn't know about the Native memory to run the 

garbage collector fast enough (the Java Object is small, the native C 

peer is *large*). You will want to call JitterMatrix.freepeer() to 

free any C resources which are not handled fast enough by the Garbage 

> Another related question is whether what i am doing is the best way 

> to convert an array into a matrix? I am fairly new to the jitter/ 

> java api and didn't see anything to directly copy an array into a 

> matrix and thus i took the buffered image route. I also use a 

> buffered image as an intermediary in converting input matrices into 

Check out JItterMatrix.CopyArrayToVector() and 

In JItter 1.6, there's a new method for filling more than a row or 

> I am experiencing what may be a memory leak when creating  
> JitterMatrix objects, consider the following code
>
> private int[]testArr = new int[200 * 200];
> private BufferedImage outTestBuf = new BufferedImage(200,200,  
> BufferedImage.TYPE_BYTE_BINARY);
>
> private void testOutput(){
>
>   //create a BufferedImage from the array	
>   outTestBuf.setRGB(0, 0, 200, 200, testArr, 0, 200);
>   //turn it into a jitter matrix and output it		
>   JitterMatrix outTest = new JitterMatrix(outTestBuf);
>   outlet(0, "jit_matrix", outTest.getName());	
>
> }

This is because Java doesn't know about the Native memory to run the  
garbage collector fast enough (the Java Object is small, the native C  
peer is *large*). You will want to call JitterMatrix.freepeer() to  
free any C resources which are not handled fast enough by the Garbage  
collector.

> Another related question is whether what i am doing is the best way  
> to convert an array into a matrix? I am fairly new to the jitter/ 
> java api and didn't see anything to directly copy an array into a  
> matrix and thus i took the buffered image route. I also use a  
> buffered image as an intermediary in converting input matrices into  
> arrays for processing.

Check out JItterMatrix.CopyArrayToVector() and  
JitterMatrix.CopyVectorToArray()

In JItter 1.6, there's a new method for filling more than a row or  
column at a time.

I modified my method to call freepeer in the following manner

outTestBuf.setRGB(0, 0, 200, 200, testArr, 0, 200);        

I had tried calling freepeer after the matrix was output, but it apparently gets destroyed before the jit.window in the patch has time to render it (jit.window gave the following error • error: jit.window: couldn't get matrix object!). So instead i free the peer just before discarding the old object and creating a new JitterMatrix (and after the old one has been rendered). However the memory consumption of max grew just as before, although the patch ran for much longer before crashing (the total memory it used was much higher). I even tried calling System.gc() at the end of the method but that had no effect.

>> Check out JItterMatrix.CopyArrayToVector() and 

I had seen these methods before but must admit i could not figure out how to use them. What is exactly is a vector in a jitter matrix, is it a row or a column? In particular the first two arguments to copyArrayToVector are unclear to me, the first, "dim" i guess is the length of the coloumn or row (which is either the width or the height of the matrix). The second argument, "offset", confuses me, why is it an array? i would have thought it would be an int to specify which row or coloumn you want to copy into. How should i specifiy an offset?

JitterMatrix outTest;
private void testOutput(){
     if(outTest != null)
	outTest.freePeer();
     //create a BufferedImage from the array	
     outTestBuf.setRGB(0, 0, 200, 200, testArr, 0, 200);		
     outTest = new JitterMatrix(outTestBuf);
     outlet(0, "jit_matrix", outTest.getName());	
}

>> Check out JItterMatrix.CopyArrayToVector() and 
>> JitterMatrix.CopyVectorToArray()

On Jul 10, 2006, at 2:43 PM, Yannick Assogba wrote:

> I had tried calling freepeer after the matrix was output, but it 

> apparently gets destroyed before the jit.window in the patch has 

> time to render it (jit.window gave the following error • 

> error: jit.window: couldn't get matrix object!). So instead i free 

> the peer just before discarding the old object and creating a new 

> JitterMatrix (and after the old one has been rendered). However the 

> memory consumption of max grew just as before, although the patch 

> ran for much longer before crashing (the total memory it used was 

> much higher). I even tried calling System.gc() at the end of the 

If you could provide us with a simple, complete example, we can 

> I had seen these methods before but must admit i could not figure 

> out how to use them. What is exactly is a vector in a jitter 

It can be a row (dim argument =0), or column(dim argument=1), or 

vector across any other dimensions(dim=N). It can also be any portion 

of a complete row, column, or vector across N-D.

> In particular the first two arguments to copyArrayToVector are 

> unclear to me, the first, "dim" i guess is the length of the 

> coloumn or row (which is either the width or the height of the 

No it is *which* dimension in the N-dimensional Jitter Matrix, *not* 

the size of the dimension. The "count" parameter determines how many 

> The second argument, "offset", confuses me, why is it an array?

It is the offset for every dimension in the N-dimensional 

JitterMatrix at which to start copying. So if you want to do a whole 

row for row 13 (zero based of course), it would be dim=0, offset[0] = 

0, and offset[1] = 13. If you wanted to just copy 4 elements into row 

13 starting at column 27, it would be offset[0] = 27, and offset[1] = 

So in summary, the important things to understand this are:

1. a jitter Matrix can have up to 32 dimensions

2. a vector in a jitter matrix can be across any one of these 

dimensions (specified by the dim argument)

3. this function can copy to any length vector in the Matrix (doesn't 

need to be the whole row, col, etc. length)

4. the offset parameter is an offset for every dimension in the matrix

5. this function can copy only part of the input array, as defined by 

However, it sounds like you don't need much more than the example 

usage inside jitvectorprocess.java. Which just does every complete 

row, one at a time. Source below for your convenience.

    public void jit_matrix(String inname)

        int[] offset = new int[2];

        JitterMatrix inmat = new JitterMatrix(inname);

        planecount = mat.getPlanecount();    

        // only alloc vec if size is different

        if ((vec==null)||(vec.length!=(dim[0]*planecount)))

            vec = new int[dim[0]*planecount];

            offset[1] = i;    

            inmat.copyVectorToArray(0,offset,vec,vec.length,0);    

            if (planecount==4) {

                for (j=0,k=0;j

                    vec[k] = 255-vec[k++];

                    for (n=0;n

                        vec[k] = 255-vec[k];

                    }

            mat.copyArrayToVector(0,offset,vec,vec.length,0);    

        outlet(0,"jit_matrix", mat.getAttr("name"));

>
> I had tried calling freepeer after the matrix was output, but it  
> apparently gets destroyed before the jit.window in the patch has  
> time to render it (jit.window gave the following error •  
> error: jit.window: couldn't get matrix object!). So instead i free  
> the peer just before discarding the old object and creating a new  
> JitterMatrix (and after the old one has been rendered). However the  
> memory consumption of max grew just as before, although the patch  
> ran for much longer before crashing (the total memory it used was  
> much higher). I even tried calling System.gc() at the end of the  
> method but that had no effect.

If you could provide us with a simple, complete example, we can  
perhaps offer you more feedback.

> I had seen these methods before but must admit i could not figure  
> out how to use them. What is exactly is a vector in a jitter  
> matrix, is it a row or a column?

It can be a row (dim argument =0), or column(dim argument=1), or  
vector across any other dimensions(dim=N). It can also be any portion  
of a complete row, column, or vector across N-D.

> In particular the first two arguments to copyArrayToVector are  
> unclear to me, the first, "dim" i guess is the length of the  
> coloumn or row (which is either the width or the height of the  
> matrix).

No it is *which* dimension in the N-dimensional Jitter Matrix, *not*  
the size of the dimension. The "count" parameter determines how many  
elements to copy.

It is the offset for every dimension in the N-dimensional  
JitterMatrix at which to start copying. So if you want to do a whole  
row for row 13 (zero based of course), it would be dim=0, offset[0] =  
0, and offset[1] = 13. If you wanted to just copy 4 elements into row  
13 starting at column 27, it would be offset[0] = 27, and offset[1] =  
13.

1. a jitter Matrix can have up to 32 dimensions
2. a vector in a jitter matrix can be across any one of these  
dimensions (specified by the dim argument)
3. this function can copy to any length vector in the Matrix (doesn't  
need to be the whole row, col, etc. length)
4. the offset parameter is an offset for every dimension in the matrix
5. this function can copy only part of the input array, as defined by  
count and arrayoffset

However, it sounds like you don't need much more than the example  
usage inside jitvectorprocess.java. Which just does every complete  
row, one at a time. Source below for your convenience.

	public void jit_matrix(String inname)
	{
		int[] dim;
		int[] offset = new int[2];
		int width;
		int height;
		int planecount;
		int i,j,k,n;
		JitterMatrix inmat = new JitterMatrix(inname);

		mat.setinfo(inname);
		dim = mat.getDim();
		planecount = mat.getPlanecount();	
		// only alloc vec if size is different
		if ((vec==null)||(vec.length!=(dim[0]*planecount)))
			vec = new int[dim[0]*planecount];

		width = dim[0];
		height = dim[1];
		offset[0] = 0;

		for (i=0;i
			offset[1] = i;	
			inmat.copyVectorToArray(0,offset,vec,vec.length,0);	
			if (planecount==4) {
				for (j=0,k=0;j
					vec[k] = 255-vec[k++];
					vec[k] = 255-vec[k++];
					vec[k] = 255-vec[k++];
					vec[k] = 255-vec[k++];
				}
			} else {
				for (j=0,k=0;j
					for (n=0;n
						vec[k] = 255-vec[k];
					}
				}
			}
			mat.copyArrayToVector(0,offset,vec,vec.length,0);	
		}	
		outlet(0,"jit_matrix", mat.getAttr("name"));
	}

>>If you could provide us with a simple, complete example, we can

I have attached a zip file containing a patch and java files (.class and src) with an example. When i run the patch, activity monitor shows the memory used by max going higher and higher, takes about 8 minutes to crash.

Thanks for the stuff on copyArrayToVector, i get it now, i will try the code in jitvectorprocess.java a bit later.

>>If you could provide us with a simple, complete example, we can
perhaps offer you more feedback.

I have attached a zip file containing a patch and java files (.class and src) with an example. When i run the patch, activity monitor shows the memory used by max going higher and higher, takes about 8 minutes to crash. 

import com.cycling74.jitter.JitterMatrix;

* Test converting an integer array into a jitter matrix and outputting it to

public class ya_jitTest extends MaxObject {

    private BufferedImage outTestBuf;

    private int blackCol = new Color(0,0,0).getRGB();

    private int whiteCol = new Color(255,255,255).getRGB();

        bail("must provide dimensions");

    public ya_jitTest(int width, int height){

        testArr = new int[width * height];

        outTestBuf = new BufferedImage(width,height, BufferedImage.TYPE_BYTE_BINARY);

        post("ya_jitTest object created");

    //simulation goes here - in this case, simple noise field is generated

        for (int j = 0; j < testArr.length; j++) {

        if (Math.random() < 0.5)          

             testArr[j] = whiteCol;

            testArr[j] = blackCol;

        //free the peer created on the last bang

            outTest.freePeer();

        //create a BufferedImage from the array    

        outTestBuf.setRGB(0, 0, width, height, testArr, 0, width);        

        outTest = new JitterMatrix(outTestBuf);

        outlet(0, "jit_matrix", outTest.getName());        

import java.awt.Color;
import java.awt.image.BufferedImage;

import com.cycling74.jitter.JitterMatrix;
import com.cycling74.max.MaxObject;

/**
 * 
 * @author Yannick Assogba
 * 
 * Test converting an integer array into a jitter matrix and outputting it to
 * max
 *
 */

	private int[]testArr;
	private BufferedImage outTestBuf;

	private int blackCol = new Color(0,0,0).getRGB();
	private int whiteCol = new Color(255,255,255).getRGB();

	public ya_jitTest(){
		bail("must provide dimensions");
	}

	public ya_jitTest(int width, int height){
		this.width = width;
		this.height = height;

		testArr = new int[width * height];
		outTestBuf = new BufferedImage(width,height, BufferedImage.TYPE_BYTE_BINARY);

	public void bang()
	{		
		initTestArr();
		output();
	}

	//simulation goes here - in this case, simple noise field is generated
	private void initTestArr(){
		for (int j = 0; j < testArr.length; j++) {
		if (Math.random() < 0.5) 		         
	  		testArr[j] = whiteCol;
		else
			testArr[j] = blackCol;
		}
	}

	JitterMatrix outTest;
	private void output(){
		//free the peer created on the last bang
		if(outTest != null)
			outTest.freePeer();
		//create a BufferedImage from the array	
		outTestBuf.setRGB(0, 0, width, height, testArr, 0, width);		
		outTest = new JitterMatrix(outTestBuf);
		outlet(0, "jit_matrix", outTest.getName());		
	}

Rather than creating a new matrix every time in your output method,

instead try using JitterMatrix's copyBufferedImage method.

> hmmm, attachment diidnt seem to work...

> #P message 322 118 70 196617 size 300 300;

> #P user jit.pwindow 160 175 302 302 0 1 0 0 1 0;

> #P newex 160 112 121 196617 mxj ya_jitTest 300 300;

> import com.cycling74.jitter.JitterMatrix;

> * Test converting an integer array into a jitter matrix and outputting it to

> public class ya_jitTest extends MaxObject {

> private int blackCol = new Color(0,0,0).getRGB();

> private int whiteCol = new Color(255,255,255).getRGB();

Rather than creating a new matrix every time in your output method,
instead try using JitterMatrix's copyBufferedImage method.

On 7/11/06, Yannick Assogba  wrote:
>
> hmmm, attachment diidnt seem to work...
>
> here is the patch
>
> max v2;
> #N vpatcher 59 359 814 916;
> #P toggle 159 43 15 0;
> #P window setfont "Sans Serif" 9.;
> #P message 322 118 70 196617 size 300 300;
> #P user jit.pwindow 160 175 302 302 0 1 0 0 1 0;
> #P newex 159 78 52 196617 metro 20;
> #P newex 160 112 121 196617 mxj ya_jitTest 300 300;
> #P connect 4 0 1 0;
> #P connect 1 0 0 0;
> #P connect 0 0 2 0;
> #P connect 3 0 2 0;
> #P pop;
>
> and here is the java code
>
> import java.awt.Color;
> import java.awt.image.BufferedImage;
>
> import com.cycling74.jitter.JitterMatrix;
> import com.cycling74.max.MaxObject;
>
> /**
>  *
>  * @author Yannick Assogba
>  *
>  * Test converting an integer array into a jitter matrix and outputting it to
>  * max
>  *
>  */
>
> public class ya_jitTest extends MaxObject {
>
>         private int width;
>         private int height;
>
>         private int[]testArr;
>         private BufferedImage outTestBuf;
>
>         private int blackCol = new Color(0,0,0).getRGB();
>         private int whiteCol = new Color(255,255,255).getRGB();
>
>         public ya_jitTest(){
>                 bail("must provide dimensions");
>         }
>
>         public ya_jitTest(int width, int height){
>                 this.width = width;
>                 this.height = height;
>
>                 testArr = new int[width * height];
>                 outTestBuf = new BufferedImage(width,height, BufferedImage.TYPE_BYTE_BINARY);
>
>                 post("ya_jitTest object created");
>         }
>
>         public void bang()
>         {
>                 initTestArr();
>                 output();
>         }
>
>         //simulation goes here - in this case, simple noise field is generated
>         private void initTestArr(){
>                 for (int j = 0; j < testArr.length; j++) {
>                 if (Math.random() < 0.5)
>                         testArr[j] = whiteCol;
>                 else
>                         testArr[j] = blackCol;
>                 }
>         }
>
>
>         JitterMatrix outTest;
>         private void output(){
>                 //free the peer created on the last bang
>                 if(outTest != null)
>                         outTest.freePeer();
>                 //create a BufferedImage from the array
>                 outTestBuf.setRGB(0, 0, width, height, testArr, 0, width);
>                 outTest = new JitterMatrix(outTestBuf);
>                 outlet(0, "jit_matrix", outTest.getName());
>         }
>
> }
>
>


The first thing I notice is that your patch uses a metronome (High 

First of all, it is not recommended unless you really know what 

you're doing to use Jitter objects in the High Priority thread (i.e. 

are issuing no drawing calls, and know that the calculations can 

happen in realtime, and do not exploit matrices which are also being 

used at low priority at the same time, leading to threading conflicts).

More importantly, there is not the automatic usurp mechanism for Java 

objects which happens for C programmed Jitter objects, which if 

attempting to execute an operation faster than possible to compute in 

real-time, messages are dropped to prevent scheduler backlog. In your 

patch, if it can't compute in realtime, you will allocate memory for 

a new event, which grows without bound, and once memory is completely 

Since this could be your problem, the way this patch is programmed, 

the first thing I would try is to use the low priority, and backlog 

safe qmetro object (as is done in almost all Java and Javascript 

example patches). For a detailed discussion of scheduler and low 

priority issues, I would read the following articles:

"Event Priority in Max (Scheduler vs. Queue)"

https://cycling74.com/story/2005/5/2/133649/9742

The Jitter C programming Guide chapter "Scheduler and Low Priority 

https://cycling74.com/twiki/bin/view/ProductDocumentation/

Let us know if you change your patch and you are still suffering from 

the same problems, and we can investigate further.

The first thing I notice is that your patch uses a metronome (High  
Priority Scheduler).

First of all, it is not recommended unless you really know what  
you're doing to use Jitter objects in the High Priority thread (i.e.  
are issuing no drawing calls, and know that the calculations can  
happen in realtime, and do not exploit matrices which are also being  
used at low priority at the same time, leading to threading conflicts).

More importantly, there is not the automatic usurp mechanism for Java  
objects which happens for C programmed Jitter objects, which if  
attempting to execute an operation faster than possible to compute in  
real-time, messages are dropped to prevent scheduler backlog. In your  
patch, if it can't compute in realtime, you will allocate memory for  
a new event, which grows without bound, and once memory is completely  
exhausted, the program will crash.

Since this could be your problem, the way this patch is programmed,  
the first thing I would try is to use the low priority, and backlog  
safe qmetro object (as is done in almost all Java and Javascript  
example patches). For a detailed discussion of scheduler and low  
priority issues, I would read the following articles:

"Event Priority in Max (Scheduler vs. Queue)"
https://cycling74.com/story/2005/5/2/133649/9742

The Jitter C programming Guide chapter "Scheduler and Low Priority  
Queue Issue"
https://cycling74.com/twiki/bin/view/ProductDocumentation/ 
JitterSdkSchedQueue

Let us know if you change your patch and you are still suffering from  
the same problems, and we can investigate further.

I have found what may be a memory leak in the C/Java bindings. For

memory issues with JitterMatrix()