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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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

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 *

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/**

 * @test

 * @bug 8057967

 *                         -XX:+PrintCompilation -XX:+TraceDependencies -XX:+TraceReferenceGC

 *                         -verbose:gc java.lang.invoke.CallSiteDepContextTest

 */

package java.lang.invoke;

import java.lang.ref.*;

import java.lang.reflect.Field;

import jdk.internal.org.objectweb.asm.*;

import sun.misc.Unsafe;

import static jdk.internal.org.objectweb.asm.Opcodes.*;

public class CallSiteDepContextTest {

    static final Unsafe               UNSAFE = Unsafe.getUnsafe();

    static final MethodHandles.Lookup LOOKUP = MethodHandles.Lookup.IMPL_LOOKUP;

    static final String           CLASS_NAME = "java/lang/invoke/Test";

    static final String          METHOD_NAME = "m";

    static final MethodType             TYPE = MethodType.methodType(int.class);

    static MutableCallSite mcs;

    static MethodHandle bsmMH;

    static {

        try {

            bsmMH = LOOKUP.findStatic(

                    CallSiteDepContextTest.class, "bootstrap",

                    MethodType.methodType(CallSite.class, MethodHandles.Lookup.class, String.class, MethodType.class));

        } catch(Throwable e) {

            throw new InternalError(e);

        }

    }

    public static CallSite bootstrap(MethodHandles.Lookup caller,

                                     String invokedName,

                                     MethodType invokedType) {

        return mcs;

    }

    static class T {

        static int f1() { return 1; }

        static int f2() { return 2; }

    }

    static byte[] getClassFile(String suffix) {

        ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);

        MethodVisitor mv;

        cw.visit(52, ACC_PUBLIC | ACC_SUPER, CLASS_NAME + suffix, null, "java/lang/Object", null);

        {

            mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, METHOD_NAME, TYPE.toMethodDescriptorString(), null, null);

            mv.visitCode();

            Handle bsm = new Handle(H_INVOKESTATIC,

                    "java/lang/invoke/CallSiteDepContextTest", "bootstrap",

                    bsmMH.type().toMethodDescriptorString());

            mv.visitInvokeDynamicInsn("methodName", TYPE.toMethodDescriptorString(), bsm);

            mv.visitInsn(IRETURN);

            mv.visitMaxs(0, 0);

            mv.visitEnd();

        }

        cw.visitEnd();

        return cw.toByteArray();

    }

    private static void execute(int expected, MethodHandle... mhs) throws Throwable {

        for (int i = 0; i < 20_000; i++) {

            for (MethodHandle mh : mhs) {

                int r = (int) mh.invokeExact();

                if (r != expected) {

                    throw new Error(r + " != " + expected);

                }

            }

        }

    }

    public static void testHiddenDepField() throws Exception {

        try {

            Field f = MethodHandleNatives.CallSiteContext.class.getDeclaredField("vmdependencies");

            throw new AssertionError("Context.dependencies field should be hidden");

        } catch(NoSuchFieldException e) { /* expected */ }

    }

    public static void testSharedCallSite() throws Throwable {

        Class<?> cls1 = UNSAFE.defineAnonymousClass(Object.class, getClassFile("CS_1"), null);

        Class<?> cls2 = UNSAFE.defineAnonymousClass(Object.class, getClassFile("CS_2"), null);

        MethodHandle[] mhs = new MethodHandle[] {

            LOOKUP.findStatic(cls1, METHOD_NAME, TYPE),

            LOOKUP.findStatic(cls2, METHOD_NAME, TYPE)

        };

        mcs = new MutableCallSite(LOOKUP.findStatic(T.class, "f1", TYPE));

        execute(1, mhs);

        mcs.setTarget(LOOKUP.findStatic(T.class, "f2", TYPE));

        execute(2, mhs);

    }

    public static void testNonBoundCallSite() throws Throwable {

        mcs = new MutableCallSite(LOOKUP.findStatic(T.class, "f1", TYPE));

        // mcs.context == null

        MethodHandle mh = mcs.dynamicInvoker();

        execute(1, mh);

        // mcs.context == cls1

        Class<?> cls1 = UNSAFE.defineAnonymousClass(Object.class, getClassFile("NonBound_1"), null);

        MethodHandle mh1 = LOOKUP.findStatic(cls1, METHOD_NAME, TYPE);

        execute(1, mh1);

        mcs.setTarget(LOOKUP.findStatic(T.class, "f2", TYPE));

        execute(2, mh, mh1);

    }

    static ReferenceQueue rq = new ReferenceQueue();

    static PhantomReference ref;

    public static void testGC(boolean clear, boolean precompile) throws Throwable {

        String id = "_" + clear + "_" + precompile;

        mcs = new MutableCallSite(LOOKUP.findStatic(T.class, "f1", TYPE));

        Class<?>[] cls = new Class[] {

                UNSAFE.defineAnonymousClass(Object.class, getClassFile("GC_1" + id), null),

                UNSAFE.defineAnonymousClass(Object.class, getClassFile("GC_2" + id), null),

        };

        MethodHandle[] mhs = new MethodHandle[] {

                LOOKUP.findStatic(cls[0], METHOD_NAME, TYPE),

                LOOKUP.findStatic(cls[1], METHOD_NAME, TYPE),

        };

        // mcs.context == cls[0]

        int r = (int) mhs[0].invokeExact();

        execute(1, mhs);

        ref = new PhantomReference<>(cls[0], rq);

        cls[0] = UNSAFE.defineAnonymousClass(Object.class, getClassFile("GC_3" + id), null);

        mhs[0] = LOOKUP.findStatic(cls[0], METHOD_NAME, TYPE);

        do {

            System.gc();

            try {

                Reference ref1 = rq.remove(100);

                if (ref1 == ref) {

                    break;

                }

            } catch(InterruptedException e) { /* ignore */ }

        } while (true);

        if (clear) {

            ref.clear();

            System.gc(); // Ensure that the stale context is unloaded

        }

        if (precompile) {

            execute(1, mhs);

        }

        mcs.setTarget(LOOKUP.findStatic(T.class, "f2", TYPE));

        execute(2, mhs);

    }

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

        testHiddenDepField();

        testSharedCallSite();

        testNonBoundCallSite();

        testGC(false, false);

        testGC(false,  true);

        testGC( true, false);

        testGC( true,  true);

        System.out.println("TEST PASSED");

    }

}