/*

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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

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * 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).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

import java.io.BufferedReader;

import java.io.InputStream;

import java.io.InputStreamReader;

import static jdk.testlibrary.Asserts.assertGreaterThan;

import jdk.testlibrary.ProcessTools;

import com.sun.tools.attach.AttachNotSupportedException;

import com.sun.tools.attach.VirtualMachine;

import sun.tools.attach.HotSpotVirtualMachine;

/*

 * @test

 * @bug 6942989

 * @summary Check for WeakReference leak in Logger and anonymous Logger objects

 * @library /lib/testlibrary

 * @run main/othervm TestLoggerWeakRefLeak Logger

 * @run main/othervm TestLoggerWeakRefLeak AnonymousLogger

 */

public class TestLoggerWeakRefLeak {

    private static final String TARGET_CLASS = "java.lang.ref.WeakReference";

    private static final int INSTANCE_COUNT = 100;

    private static int loggerCount = 0;

    public static void main(String[] args) throws Exception {

        if (args[0].equals("AnonymousLogger")) {

            System.out.println("Test for WeakReference leak in AnonymousLogger object");

            testIfLeaking(TestLoggerWeakRefLeak::callAnonymousLogger);

        } else {

            System.out.println("Test for WeakReference leak in Logger object");

            testIfLeaking(TestLoggerWeakRefLeak::callLogger);

        }

    }

    /**

     * For these particular WeakReference leaks, the count was always observed

     * to be increasing so if decreasing or the same count is observed,

     * then there is no leak.

     */

    private static void testIfLeaking(Runnable callLogger) throws Exception {

        long count = 0;

        int instanceCount = 0;

        int previousInstanceCount = 0;

        int increasingCount = 0;

        int decreasingCount = 0;

        while (true) {

            callLogger.run();

            count += INSTANCE_COUNT;

            if ((count % 1000) == 0) {

                System.out.println("call count = " + count);

                instanceCount = getInstanceCountFromHeapHisto();

                if (instanceCount > previousInstanceCount) {

                    increasingCount++;

                } else {

                    decreasingCount++;

                    System.out.println("increasing count: " + increasingCount);

                    System.out.println("decreasing or the same count: " + decreasingCount);

                    System.out.println("Test passed: decreasing or the same instance count is observed");

                    break;

                }

                previousInstanceCount = instanceCount;

            }

            delayExecution();

        }

    }

    /**

     * This Logger call is leaking two different WeakReferences:

     * - one in LogManager.LogNode

     * - one in Logger.kids

     */

    private static void callLogger() {

        for (int i = 0; i < INSTANCE_COUNT; i++) {

            java.util.logging.Logger.getLogger("logger-" + loggerCount);

            if (++loggerCount >= 25000) {

                // Limit the Logger namespace used by the test so the weak refs

                // in LogManager.loggers that are being properly managed

                // don't skew the counts by too much.

                loggerCount = 0;

            }

        }

    }

    /**

     * This Logger call is leaking a WeakReference in Logger.kids

     */

    private static void callAnonymousLogger() {

        for (int i = 0; i < INSTANCE_COUNT; i++) {

            java.util.logging.Logger.getAnonymousLogger();

        }

    }

    /**

     * 'vm.heapHisto("-live")' will request a full GC

     */

    private static int getInstanceCountFromHeapHisto() throws AttachNotSupportedException, Exception {

        int instanceCount = 0;

        HotSpotVirtualMachine vm = (HotSpotVirtualMachine) VirtualMachine

                .attach(Integer.toString(ProcessTools.getProcessId()));

        try {

            try (InputStream heapHistoStream = vm.heapHisto("-live");

                    BufferedReader in = new BufferedReader(new InputStreamReader(heapHistoStream))) {

                String inputLine;

                while ((inputLine = in.readLine()) != null) {

                    if (inputLine.contains(TARGET_CLASS)) {

                        instanceCount = Integer.parseInt(inputLine

                                .split("[ ]+")[2]);

                        System.out.println("instance count: " + instanceCount);

                        break;

                    }

                }

            }

        } finally {

            vm.detach();

        }

        assertGreaterThan(instanceCount, 0, "No instances of " + TARGET_CLASS + " are found");

        return instanceCount;

    }

    /**

     * Delay for 1/10 of a second to avoid CPU saturation

     */

    private static void delayExecution() {

        try {

            Thread.sleep(100);

        } catch (InterruptedException ie) {

            // Ignore any exceptions

        }

    }

}