Strange Output of Thread

Question

Hi Friends
I am getting very strange out put of the following code
Plz explain!!!!!!!
class BasicBlob {                                     // (1)
    static    int idCounter;
    static    int population;
    protected int blobId;
    BasicBlob() {
        blobId = idCounter++;
        ++population;
    protected void finalize() throws Throwable {      // (2)
        --population;
        super.finalize();
class Blob extends BasicBlob {                        // (3)
    int[] fat;
    Blob(int bloatedness) {                           // (4)
        fat = new int[bloatedness];
        System.out.println(blobId + ": Hello");
    protected void finalize() throws Throwable {      // (5)
        System.out.println(blobId + ": Bye");
        super.finalize();
public class Finalizers {
   public static void main(String[] args) {          // (6)
        int blobsRequired, blobSize;
        try {
            blobsRequired = Integer.parseInt(args[0]);
            blobSize      = Integer.parseInt(args[1]);
        } catch(IndexOutOfBoundsException e) {
            System.err.println(
                "Usage: Finalizers <number of blobs> <blob size>");
            return;
        for (int i=0; i<=blobsRequired; ++i) {         // (7)
            new Blob(blobSize);
        System.out.println(BasicBlob.population + " blobs alive"); // (8)
   When I give the i/p 5 500000
O/P is--------------------------
0: Hello
0: Bye
1: Hello
1: Bye
2: Hello
2: Bye
3: Hello
3: Bye
4: Hello ////////// Why not Bye again as above 1 blobs alive
1 blobs alive

Answer 1

This has to do with whether Garbage Collector is collecting your unreferenced objects or not. In this case you are specifying a size of 500000, which from ur code is size of an array of integers (each 4 byte). so a single allocation of array corresponds to roughly 500000*4 bytes. On this size jvm heap will run out of memory for even 2 such objects and hence when it goes to create second object GC runs and your previous object is GC'ed. But for last object created this is not the case.
U can try changing 500000 with a lesser value, say 500. All of your blobs will remain alive (if unfortunately they are not gc'ed :)).