jdk-24/test/hotspot/jtreg/runtime/jni/FastGetField/FastGetField.java

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/**
 * @test
 * @bug 8227680
 * @summary Tests that all FieldAccess notifications for Get*Field
            with primitive type are generated.
 * @requires vm.jvmti
 * @compile FastGetField.java
 * @run main/othervm/native -agentlib:FastGetField -XX:+IgnoreUnrecognizedVMOptions -XX:-VerifyJNIFields FastGetField 0
 * @run main/othervm/native -agentlib:FastGetField -XX:+IgnoreUnrecognizedVMOptions -XX:-VerifyJNIFields FastGetField 1
 * @run main/othervm/native -agentlib:FastGetField -XX:+IgnoreUnrecognizedVMOptions -XX:-VerifyJNIFields FastGetField 2
 * @run main/othervm/native -agentlib:FastGetField -XX:+IgnoreUnrecognizedVMOptions -XX:-VerifyJNIFields -XX:+UnlockDiagnosticVMOptions -XX:+ForceUnreachable -XX:+SafepointALot -XX:GuaranteedSafepointInterval=1 FastGetField 0
 * @run main/othervm/native -agentlib:FastGetField -XX:+IgnoreUnrecognizedVMOptions -XX:-VerifyJNIFields -XX:+UnlockDiagnosticVMOptions -XX:+ForceUnreachable -XX:+SafepointALot -XX:GuaranteedSafepointInterval=1 FastGetField 1
 * @run main/othervm/native -agentlib:FastGetField -XX:+IgnoreUnrecognizedVMOptions -XX:-VerifyJNIFields -XX:+UnlockDiagnosticVMOptions -XX:+ForceUnreachable -XX:+SafepointALot -XX:GuaranteedSafepointInterval=1 FastGetField 2
 */

import java.lang.reflect.Field;

public class FastGetField {

    private static final String agentLib = "FastGetField";

    private native boolean initFieldIDs(Class c);
    private native boolean initWatchers(Class c);
    public native void registerGlobal(MyItem i);
    public native void registerWeak(MyItem i);
    public native long accessFields(MyItem i);
    public native long accessFieldsViaHandle();
    public static native long getFieldAccessCount();

    static final int loop_cnt = 10000;


    class MyItem {
        // Names should match JNI types.
        boolean Z;
        byte B;
        short S;
        char C;
        int I;
        long J;
        float F;
        double D;

        public void change_values() {
            Z = true;
            B = 1;
            C = 1;
            S = 1;
            I = 1;
            J = 1l;
            F = 1.0f;
            D = 1.0;
        }

        public void reset_values() {
            Z = false;
            B = 0;
            C = 0;
            S = 0;
            I = 0;
            J = 0l;
            F = 0.0f;
            D = 0.0;
        }
    }

    // Static initialization.
    static {
        try {
            System.loadLibrary(agentLib);
        } catch (UnsatisfiedLinkError ex) {
            System.err.println("Failed to load " + agentLib + " lib");
            System.err.println("java.library.path: " + System.getProperty("java.library.path"));
            throw ex;
        }
    }

    private int mode;
    private MyItem obj;

    private FastGetField(int mode) {
        this.mode = mode;
        this.obj = new MyItem();

        if (mode == 0) {
            // Direct
        } else if (mode == 1) {
            registerGlobal(this.obj);
        } else if ( mode == 2) {
            registerWeak(this.obj);
        } else {
          throw new IllegalArgumentException("Unexpected mode");
        }
    }

    private long accessFields() {
        if (mode == 0) {
            return accessFields(obj);
        }

        // Otherwise through a handle
        return accessFieldsViaHandle();
    }

    public void TestFieldAccess() throws Exception {

        if (!initFieldIDs(MyItem.class)) throw new RuntimeException("FieldID initialization failed!");

        long duration = System.nanoTime();
        for (int c = 0; c < loop_cnt; ++c) {
            if (accessFields() != 0l) throw new RuntimeException("Wrong initial result!");
            obj.change_values();
            if (accessFields() != 8l) throw new RuntimeException("Wrong result after changing!");
            obj.reset_values();
        }
        duration = System.nanoTime() - duration;
        System.out.println(loop_cnt + " iterations took " + duration + "ns.");

        if (getFieldAccessCount() != 0) throw new RuntimeException("Watch not yet active!");

        // Install watchers.
        if (!initWatchers(MyItem.class)) throw new RuntimeException("JVMTI missing!");

        // Try again with watchers.
        if (accessFields() != 0l) throw new RuntimeException("Wrong initial result!");
        obj.change_values();
        if (accessFields() != 8l) throw new RuntimeException("Wrong result after changing!");
        if (getFieldAccessCount() != 16) throw new RuntimeException("Unexpected event count!");
    }

    public static void main(String[] args) throws Exception {
        if (args.length != 1) {
           throw new IllegalArgumentException("Expected one argument");
        }

        int mode = Integer.parseInt(args[0]);

        FastGetField inst = new FastGetField(mode);
        inst.TestFieldAccess();
    }
}