TestObjectAllocationOutsideTLABEvent.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
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 *
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * 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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package jdk.jfr.event.allocation;

import static java.lang.Math.floor;

import jdk.jfr.Recording;
import jdk.jfr.consumer.RecordedEvent;
import jdk.test.lib.jfr.EventNames;
import jdk.test.lib.jfr.Events;
import jdk.test.lib.Asserts;
import jdk.test.lib.Platform;
import sun.hotspot.WhiteBox;

/**
 * @test
 * @summary Test that when an object is allocated outside a TLAB an event will be triggered.
 * @key jfr
 * @requires vm.hasJFR
 * @library /test/lib
 * @build sun.hotspot.WhiteBox
 *
 * @run driver jdk.test.lib.helpers.ClassFileInstaller sun.hotspot.WhiteBox
 * @run main/othervm -XX:+WhiteBoxAPI -Xbootclasspath/a:.
 *                   -XX:+UseTLAB -XX:TLABSize=90k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=256
 *                   jdk.jfr.event.allocation.TestObjectAllocationOutsideTLABEvent
 * @run main/othervm -XX:+WhiteBoxAPI -Xbootclasspath/a:.
 *                   -XX:+UseTLAB -XX:TLABSize=90k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=256
 *                   -Xint
 *                   jdk.jfr.event.allocation.TestObjectAllocationOutsideTLABEvent
 */

/**
 * Test that an event is triggered when an object is allocated outside a
 * Thread Local Allocation Buffer (TLAB). The test is done for default interpreted mode (-Xint).
 *
 * To force objects to be allocated outside TLAB:
 *      the initial size of TLAB is set to 90k (-XX:TLABSize=90k);
 *      the size of allocated objects is set to 128k;
 *      max TLAB waste at refill is set to 256 (-XX:TLABRefillWasteFraction=256),
 *          to prevent a new TLAB creation.
*/
public class TestObjectAllocationOutsideTLABEvent {
    private static final String EVENT_NAME = EventNames.ObjectAllocationOutsideTLAB;

    private static final Boolean COMPRESSED_CLASS_PTRS = WhiteBox.getWhiteBox().getBooleanVMFlag("UseCompressedClassPointers");

    private static final int BYTE_ARRAY_OVERHEAD = (Platform.is64bit() && !COMPRESSED_CLASS_PTRS) ? 24 : 16;
    private static final int OBJECT_SIZE = 128 * 1024;

    private static final int OBJECTS_TO_ALLOCATE = 100;
    private static final String BYTE_ARRAY_CLASS_NAME = new byte[0].getClass().getName();
    private static int eventCount;

    // Make sure allocation isn't dead code eliminated.
    public static byte[] tmp;

    public static void main(String[] args) throws Exception {
        Recording recording = new Recording();
        recording.enable(EVENT_NAME);
        recording.start();
        allocate();
        recording.stop();
        verifyRecording(recording);
        int minCount = (int) floor(OBJECTS_TO_ALLOCATE * 0.80);
        Asserts.assertGreaterThanOrEqual(eventCount, minCount, "Too few objects allocated");
        Asserts.assertLessThanOrEqual(eventCount, OBJECTS_TO_ALLOCATE, "Too many objects allocated");
    }

    private static void allocate() {
        for (int i = 0; i < OBJECTS_TO_ALLOCATE; ++i) {
            tmp = new byte[OBJECT_SIZE - BYTE_ARRAY_OVERHEAD];
        }
    }

    private static void verifyRecording(Recording recording) throws Exception {
        for (RecordedEvent event : Events.fromRecording(recording)) {
            verify(event);
        }
    }

    private static void verify(RecordedEvent event) {
        if (Thread.currentThread().getId() != event.getThread().getJavaThreadId()) {
            return;
        }
        long allocationSize = Events.assertField(event, "allocationSize").atLeast(1L).getValue();
        String className = Events.assertField(event, "objectClass.name").notEmpty().getValue();
        if (className.equals(BYTE_ARRAY_CLASS_NAME) && (allocationSize == OBJECT_SIZE)) {
            ++eventCount;
        }
    }
}