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

package gc.g1;

/*
 * @test TestCodeCacheUnloadDuringConcurrentMark
 * @summary Tests that G1 concurrent marking unloads a freshly not-entrant nmethod.
 * @requires vm.gc.G1
 * @requires vm.flagless
 * @requires vm.compiler1.enabled
 * @requires vm.opt.ClassUnloading != false
 * @requires vm.opt.ClassUnloadingWithConcurrentMark != false
 * @requires vm.opt.MethodFlushing != false
 * @library /test/lib /
 * @modules java.base/jdk.internal.misc
 *          java.management
 * @build jdk.test.whitebox.WhiteBox
 * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
 *                   -XX:+WhiteBoxAPI -Xbatch -XX:-BackgroundCompilation
 *                   -XX:+UseG1GC
 *                   -XX:+ClassUnloadingWithConcurrentMark
 *                   gc.g1.TestCodeCacheUnloadDuringConcurrentMark
 */

import java.lang.reflect.Method;

import gc.testlibrary.CodeCacheUtils;
import jdk.test.whitebox.WhiteBox;
import jdk.test.whitebox.code.NMethod;

public class TestCodeCacheUnloadDuringConcurrentMark {
    private static final WhiteBox WB = WhiteBox.getWhiteBox();

    static class Target {
        public static int test(int value) {
            return value + 1;
        }
    }

    private static int compileAndMakeNotEntrant(Method method) throws Exception {
        Target.test(1);
        if (!WB.enqueueMethodForCompilation(method, 1 /* compLevel */)) {
            throw new AssertionError("Failed to enqueue target for compilation");
        }
        while (WB.isMethodQueuedForCompilation(method)) {
            Thread.sleep(50);
        }
        NMethod nmethod = NMethod.get(method, false);
        if (nmethod == null || nmethod.comp_level != 1) {
            throw new AssertionError("Target is not compiled at level 1");
        }

        int deoptimized = WB.deoptimizeMethod(method);
        if (deoptimized == 0) {
            throw new AssertionError("No target nmethod was made not-entrant");
        }
        return nmethod.compile_id;
    }

    public static void main(String[] args) throws Exception {
        // Keep an automatic cycle from reclaiming the target before the
        // test-owned concurrent mark reaches it.
        WB.concurrentGCAcquireControl();
        try {
            Method method = Target.class.getDeclaredMethod("test", int.class);
            int compileId = compileAndMakeNotEntrant(method);
            if (!CodeCacheUtils.codelistContains(compileId, method, 1, 1 /* not_entrant */)) {
                throw new AssertionError("Expected a not-entrant target nmethod before concurrent mark");
            }

            int completedCycles = WB.g1CompletedConcurrentMarkCycles();
            WB.concurrentGCRunTo(WB.AFTER_MARKING_STARTED);
            WB.concurrentGCRunToIdle();
            if (completedCycles >= WB.g1CompletedConcurrentMarkCycles()) {
                throw new AssertionError("Concurrent GC aborted");
            }

            if (CodeCacheUtils.codelistContains(compileId, method, 1, 1 /* not_entrant */)) {
                throw new AssertionError("Expected concurrent mark to unload the not-entrant target nmethod");
            }
        } finally {
            WB.concurrentGCReleaseControl();
        }
    }
}