/*

 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

 * 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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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 */

package java.lang.invoke;

import java.lang.reflect.Method;

import java.util.Properties;

import sun.hotspot.WhiteBox;

public class StableConfiguration {

    static final WhiteBox WB = WhiteBox.getWhiteBox();

    static final boolean isStableEnabled;

    static final boolean isServerWithStable;

    static {

        Boolean value = WB.getBooleanVMFlag("FoldStableValues");

        isStableEnabled = (value == null ? false : value);

        isServerWithStable = isStableEnabled && get();

        System.out.println("@Stable:         " + (isStableEnabled ? "enabled" : "disabled"));

        System.out.println("Server Compiler: " + get());

    }

    // The method 'get' below returns true if the method is server compiled

    // and is used by the Stable tests to determine whether methods in

    // general are being server compiled or not as the -XX:+FoldStableValues

    // option is only applicable to -server.

    //

    // On aarch64 we DeOptimize when patching. This means that when the

    // method is compiled as a result of -Xcomp it DeOptimizes immediately.

    // The result is that getMethodCompilationLevel returns 0. This means

    // the method returns true based on java.vm.name.

    //

    // However when the tests are run with -XX:+TieredCompilation and

    // -XX:TieredStopAtLevel=1 this fails because methods will always

    // be client compiled.

    //

    // Solution is to add a simple method 'get1' which should never be

    // DeOpted and use that to determine the compilation level instead.

    static void get1() {

    }

    // ::get() is among immediately compiled methods.

    static boolean get() {

        try {

            get1();

            Method m = StableConfiguration.class.getDeclaredMethod("get1");

            int level = WB.getMethodCompilationLevel(m);

            if (level > 0) {

              return (level == 4);

            } else {

              String javaVM = System.getProperty("java.vm.name", "");

              if (javaVM.contains("Server")) return true;

              if (javaVM.contains("Client")) return false;

              throw new Error("Unknown VM type: "+javaVM);

            }

        } catch (NoSuchMethodException e) {

            throw new Error(e);

        }

    }

}