/*
 * Copyright (c) 2019, 2019, 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 com.oracle.svm.core.code;

import org.graalvm.nativeimage.c.function.CodePointer;
import org.graalvm.word.UnsignedWord;

import com.oracle.svm.core.annotate.Uninterruptible;
import com.oracle.svm.core.c.NonmovableArrays;

Provides access to UntetheredCodeInfo objects. All methods in here should only be called from uninterruptible code as the GC could free the UntetheredCodeInfo otherwise. /**
 * Provides access to {@link UntetheredCodeInfo} objects. All methods in here should only be called
 * from uninterruptible code as the GC could free the {@link UntetheredCodeInfo} otherwise.
 */
public final class UntetheredCodeInfoAccess {
    private UntetheredCodeInfoAccess() {
    }

    
Try to avoid using this method. It provides direct access to the tether object without any
verification. The return type of this method is Object instead of CodeInfoTether to avoid
type casts that could fail if a GC is in progress.
/**
     * Try to avoid using this method. It provides direct access to the tether object without any
     * verification. The return type of this method is Object instead of CodeInfoTether to avoid
     * type casts that could fail if a GC is in progress.
     */
    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.")
    public static Object getTetherUnsafe(UntetheredCodeInfo info) {
        return getObjectFieldUnsafe(info, CodeInfoImpl.TETHER_OBJFIELD);
    }

    
See Also:
CodeInfoImpl.getCodeStart/** @see CodeInfoImpl#getCodeStart */
    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.", callerMustBe = true)
    public static CodePointer getCodeStart(UntetheredCodeInfo info) {
        return cast(info).getCodeStart();
    }

    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.", callerMustBe = true)
    public static CodePointer getCodeEnd(UntetheredCodeInfo info) {
        CodeInfoImpl codeInfo = cast(info);
        return (CodePointer) ((UnsignedWord) codeInfo.getCodeStart()).add(codeInfo.getCodeSize());
    }

    
See Also:
CodeInfoImpl.getCodeSize/** @see CodeInfoImpl#getCodeSize */
    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.", callerMustBe = true)
    public static UnsignedWord getCodeSize(UntetheredCodeInfo info) {
        return cast(info).getCodeSize();
    }

    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.", callerMustBe = true)
    public static int getTier(UntetheredCodeInfo info) {
        return cast(info).getTier();
    }

    @SuppressWarnings("unchecked")
    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.", callerMustBe = true)
    public static <T> T getObjectFieldUnsafe(UntetheredCodeInfo info, int index) {
        return (T) NonmovableArrays.getObject(cast(info).getObjectFields(), index);
    }

    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.", callerMustBe = true)
    public static int getState(UntetheredCodeInfo info) {
        return cast(info).getState();
    }

    
See Also:
CodeInfoAccess.isAliveState/** @see com.oracle.svm.core.code.CodeInfoAccess#isAliveState */
    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.", callerMustBe = true)
    public static boolean isAlive(UntetheredCodeInfo info) {
        return CodeInfoAccess.isAliveState(cast(info).getState());
    }

    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.", callerMustBe = true)
    public static String getName(UntetheredCodeInfo info) {
        return getObjectFieldUnsafe(info, CodeInfoImpl.NAME_OBJFIELD);
    }

    @Uninterruptible(reason = "Must prevent the GC from freeing the CodeInfo object.", callerMustBe = true)
    private static CodeInfoImpl cast(UntetheredCodeInfo info) {
        assert info.isNonNull();
        return (CodeInfoImpl) info;
    }
}