1) If run as follows:

java -verbosegc -mx50000 -ms50000 lotsofobjects

... it just exits. Uncool, but no biggie.

2) If run as:

java -verbosegc -mx100000 -ms100000 lotsofobjects

It fails. It fails before my main is called.
Uncool. Don't fix this first!

Then it fails allocating Object.
The bug I care about is in allocating Object.
It shows a heap that is 7% free (6k) but there
is no room for an 8 byte object. It can't
be fragmentation (I claim/I hope) since
my -mx and -ms numbers are the same.

After it fails, the next allocation works!
The "stride" between failures is 770.


europa 262: java -verbosegc -mx100000 -ms100000 lotsofobjects
<GC: managing allocation failure. need 8200 bytes, type=1, action=1>
<GC: freed 138 objects, 5448 bytes in 6 ms, 7% free (6616/85192)>
  <GC: init&scan: 1 ms, scan handles: 2 ms, sweep: 0 ms, compact: 3 ms>
<GC: managing allocation failure. need 8200 bytes, type=1, action=2>
<GC: managing allocation failure. need 8200 bytes, type=1, action=3>
<GC: managing allocation failure. need 8200 bytes, type=1, action=4>
<GC: tried to expand object space over limit>
<GC: managing allocation failure. need 8200 bytes, type=1, action=5>
<GC: totally out of heap space>
started
<GC: managing allocation failure. need 8 bytes, type=1, action=1>
<GC: freed 779 objects, 6560 bytes in 2 ms, 7% free (6560/85192)>
  <GC: init&scan: 0 ms, scan handles: 2 ms, sweep: 0 ms, compact: 0 ms>
<GC: managing allocation failure. need 8 bytes, type=1, action=2>
<GC: managing allocation failure. need 8 bytes, type=1, action=3>
<GC: managing allocation failure. need 8 bytes, type=1, action=4>
<GC: tried to expand object space over limit>
<GC: managing allocation failure. need 8 bytes, type=1, action=5>
<GC: totally out of heap space>
out of memory at loopcnt 770
<GC: managing allocation failure. need 8 bytes, type=1, action=1>
<GC: freed 781 objects, 6440 bytes in 2 ms, 7% free (6440/85192)>
  <GC: init&scan: 0 ms, scan handles: 2 ms, sweep: 0 ms, compact: 0 ms>
<GC: managing allocation failure. need 8 bytes, type=1, action=2>
<GC: managing allocation failure. need 8 bytes, type=1, action=3>
<GC: managing allocation failure. need 8 bytes, type=1, action=4>
<GC: tried to expand object space over limit>
<GC: managing allocation failure. need 8 bytes, type=1, action=5>
<GC: totally out of heap space>
out of memory at loopcnt 1541
...

class sample:


public class lotsofobjects extends Thread {

    public static void main(String args[]) {
        System.out.println("started");
        int loopcnt;
        Object s;
        for(loopcnt=1; ;loopcnt++ ){
            Object t = null;
            try {
                t = new Object();
                if (loopcnt%1000 == 0) s = new Object();
            }
            catch (OutOfMemoryError e) {
                System.out.println("out of memory at loopcnt " + loopcnt);
                try {Thread.sleep(44);} catch (InterruptedException y){};
            }
            t = null;
        }
    }

}