mallocWithGC2.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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,
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/*
 * @test
 *
 * @summary converted from VM Testbase gc/gctests/mallocWithGC2.
 * VM Testbase keywords: [gc]
 * VM Testbase readme:
 * LD_LIBRARY PATH must include "$TESTBASE/src/misc/gc/utils/lib/sparc(or i386)"
 * while running these tests. The native code for all the mallocWithGC* tests
 * has been bunched up into a single .so.
 * In this test, 2 threads are created, one thread(javaHeapEater)
 * creates garbage by nulling out the elements of a vector, which formerly
 * held points to circular linked lists. These elements are again repopulated
 * with new linked lists. The second thread invokes a native function
 * that continually mallocs and frees one byte of memory for 3 minutes
 * a hold on a malloc lock.
 * The difference between mallocWithGC1 mallocWithGC2 is the way the locks
 * are held. here the "malloc" lock is more efficiently held, not by
 * the expiration of a timer but as long as the java heap devourer thread
 * stays alive.
 * The idea here is  to see if the vm deadlocks (if it does, it is ofcourse
 * a failure ). This test was created because of the following problem
 * that the vm used to have :
 *  "The malloc/GC deadlock problem is that a gc may suspend a thread (in native
 * or VM code) that is in the middle of a malloc, so it has the "malloc" lock.
 * GC may want to do a malloc, but it can't get the lock, so it deadlocks. "
 *
 * @library /vmTestbase
 *          /test/lib
 * @run main/othervm/native gc.gctests.mallocWithGC2.mallocWithGC2
 */

package gc.gctests.mallocWithGC2;

import nsk.share.test.*;
import nsk.share.gc.*;
import nsk.share.TestFailure;
import java.util.Vector;

public class mallocWithGC2 extends TestBase {
        static {
                System.loadLibrary("mallocWithGC2");
        }

        public native void getMallocLock02();

        private class javaHeapEater extends Thread {
                private Vector v;

                javaHeapEater(Vector v) {
                        this.v = v;
                }

                public void run() throws OutOfMemoryError {
                        int  gc_count;

                        for(int i = 0; i < 10 ; i++)
                                v.addElement(buildCircularLinkedList());
                        gc_count = 0;
                        while( gc_count < 10 ) {

                                for(int i = 0; i < 10 ; i++)
                                        v.setElementAt(null, i);

                                for(int i = 0; i < 10  ; i++)
                                        v.setElementAt(buildCircularLinkedList(),i);

                                gc_count++;
                                log.info("Finished iteration # " + gc_count);
                        }
                }
        }


        private class cHeapEater extends Thread{
                public void run() {
                        getMallocLock02();
                }
        }

        public void run() {
                Vector v = new Vector(10);
                Thread tArray[] = new Thread[2];

                tArray[0] = new javaHeapEater(v);
                tArray[1] = new cHeapEater();

                try {
                        for(int i = 0; i < tArray.length ; i++ )
                                tArray[i].start();

                        tArray[0].join(); // wait for the javaHeapEater Thread to finish
                        tArray[1].stop(); // Once javaHeapEater is finished, stop the
                        // the cHeapEater thread.
                } catch (Exception e) {
                        throw new TestFailure("Test Failed.", e);
                }
                log.info("Test Passed.");
        }

        // build a circular linked list of 0.2 Meg

        private CircularLinkedList buildCircularLinkedList() {
                CircularLinkedList cl;

                cl = new CircularLinkedList(100);
                for(int i = 0; i < 2000; i++)
                        cl.grow();
                return cl;
        }

        public static void main(String args[]) {
                Tests.runTest(new mallocWithGC2(), args);
        }

}