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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 *

 * 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.

 *

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 */

/*

 * @test TestReclaimStringsLeaksMemory

 * @bug 8180048

 * @summary Ensure that during a Full GC interned string memory is reclaimed completely.

 * @key gc

 * @library /test/lib

 * @modules java.base/jdk.internal.misc

 * @run main/othervm TestReclaimStringsLeaksMemory

 * @run main/othervm TestReclaimStringsLeaksMemory -XX:+UseSerialGC

 * @run main/othervm TestReclaimStringsLeaksMemory -XX:+UseParallelGC

 * @run main/othervm TestReclaimStringsLeaksMemory -XX:+UseParallelGC -XX:-UseParallelOldGC

 * @run main/othervm TestReclaimStringsLeaksMemory -XX:+UseConcMarkSweepGC

 * @run main/othervm TestReclaimStringsLeaksMemory -XX:+UseG1GC

 */

import java.util.Arrays;

import java.util.ArrayList;

import java.util.regex.Pattern;

import java.util.regex.Matcher;

import jdk.test.lib.Asserts;

import jdk.test.lib.process.OutputAnalyzer;

import jdk.test.lib.process.ProcessTools;

public class TestReclaimStringsLeaksMemory {

    // The amount of memory in kB reserved in the "Symbol" category that indicates a memory leak for

    // this test.

    public static final int ReservedThreshold = 70000;

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

        ArrayList<String> baseargs = new ArrayList(Arrays.asList( "-Xms256M",

                                                                  "-Xmx256M",

                                                                  "-Xlog:gc*",

                                                                  "-XX:NativeMemoryTracking=summary",

                                                                  "-XX:+UnlockDiagnosticVMOptions",

                                                                  "-XX:+PrintNMTStatistics" ));

        baseargs.addAll(Arrays.asList(args));

        baseargs.add(GCTest.class.getName());

        ProcessBuilder pb_default =

            ProcessTools.createJavaProcessBuilder(baseargs.toArray(new String[] {}));

        verifySymbolMemoryUsageNotTooHigh(new OutputAnalyzer(pb_default.start()));

    }

    private static void verifySymbolMemoryUsageNotTooHigh(OutputAnalyzer output) throws Exception {

        String stdout = output.getStdout();

        System.out.println(stdout);

        Pattern p = Pattern.compile("Symbol \\(reserved=(\\d*)");

        Matcher m = p.matcher(stdout);

        if (!m.find()) {

            throw new RuntimeException("Could not find Symbol memory usage in NMT output");

        }

        int reserved = Integer.parseInt(m.group(1));

        Asserts.assertLT(reserved, ReservedThreshold, "Reserved memory size is " + reserved + "KB which is greater than or equal to " + ReservedThreshold + "KB indicating a memory leak");

        output.shouldHaveExitValue(0);

    }

    static class GCTest {

        public static final String BaseName = "SomeRandomBaseString";

        public static volatile String lastString;

        public static void main(String [] args) {

            for (int iterations = 0; iterations < 20;) {

                for (int i = 0; i < 1000000; i++) {

                    lastString = (BaseName + i).intern();

                }

                if (++iterations % 5 == 0) {

                   System.gc();

                }

            }

        }

    }

}