MTsyncGC.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
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 *
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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/*
 * @test
 *
 * @summary converted from VM Testbase gc/gctests/MTsyncGC.
 * VM Testbase keywords: [gc]
 * VM Testbase readme:
 * This test creates 1000 threads that run in a sequential
 * fashion with each thread in turn generating 1Meg of garbage.
 * Before exiting, each of these threads synchronously calls
 * the garbage collector in another thread.
 * The test fails if an OutOfMemoryError is thrown and passes
 * if nothing happens.
 *
 * @library /vmTestbase
 *          /test/lib
 * @run main/othervm gc.gctests.MTsyncGC.MTsyncGC
 */

package gc.gctests.MTsyncGC;

import nsk.share.TestFailure;
import java.util.Vector;




// Each thread creates 1Meg of garbage in the run() method.

class MemEvil extends Thread {
    static Vector v = new Vector();
    static {
        for(int i = 0; i < 10; i++)
           v.addElement(new char [100000]);
    }

    public void run () {
        int i = 0;
        while(i < 10) {
           v.setElementAt(new char[100000], i);
           i++;
        }
        try {
            //synchronously invoke the garbage
            // collector in  another thread
           MTsyncGC.reclaimer.start();
           MTsyncGC.reclaimer.join();
        }catch (Exception e) {}
   }
}


class Reclaimer extends Thread{
    public void run() {
       System.gc();
    }
}

public class MTsyncGC {
    static Reclaimer reclaimer = new Reclaimer();
    public static void main(String args[] ){
       int i;
       int memory_reserve[] = new int [10000];
       Thread threadsHolder[] = new Thread[1000];

       for(i = 0; i < threadsHolder.length; i++)
           threadsHolder[i] = new MemEvil();

       i = 0;
       while(i < threadsHolder.length ){
           try {
              threadsHolder[i].start();
              threadsHolder[i].join();
           } catch ( Exception  e ) {
                memory_reserve = null;
                System.gc();
                throw new TestFailure("Test Failed.", e);
           }
           threadsHolder[i] = null;
           i++;
       }
   }
}