/*

 * 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.

 *

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.internal.vm.compiler.word;

/**

 * Lowest-level memory access of native C memory.

 * <p>

 * Do not use these methods to access Java objects. These methods access the raw memory without any

 * null checks, read- or write barriers. Even when the VM uses compressed pointers, then readObject

 * and writeObject methods access uncompressed pointers.

 *

 * @since 19.0

 */

public interface Pointer extends UnsignedWord, PointerBase {

    /**

     * Unsafe conversion of this Pointer to a Java language object. No correctness checks or type

     * checks are performed. The caller must ensure that the Pointer contains a valid Java object

     * that can i.e., processed by the garbage collector.

     *

     * @return this Pointer cast to Object.

     *

     * @since 19.0

     */

    Object toObject();

    /**

     * Unsafe conversion of this Pointer to a Java language object. No correctness checks or type

     * checks are performed. The caller must ensure that the Pointer contains a valid Java object

     * that can i.e., processed by the garbage collector and the Pointer does not contain 0.

     *

     * @return this Pointer cast to non-null Object.

     *

     * @since 19.0

     */

    Object toObjectNonNull();

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    byte readByte(WordBase offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    char readChar(WordBase offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    short readShort(WordBase offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    int readInt(WordBase offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    long readLong(WordBase offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    float readFloat(WordBase offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    double readDouble(WordBase offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    <T extends WordBase> T readWord(WordBase offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    Object readObject(WordBase offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    byte readByte(int offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    char readChar(int offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    short readShort(int offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    int readInt(int offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    long readLong(int offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    float readFloat(int offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    double readDouble(int offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    <T extends WordBase> T readWord(int offset, LocationIdentity locationIdentity);

    /**

     * Reads the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the read

     * @return the result of the memory access

     *

     * @since 19.0

     */

    Object readObject(int offset, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeByte(WordBase offset, byte val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeChar(WordBase offset, char val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeShort(WordBase offset, short val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeInt(WordBase offset, int val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeLong(WordBase offset, long val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeFloat(WordBase offset, float val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeDouble(WordBase offset, double val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeWord(WordBase offset, WordBase val, LocationIdentity locationIdentity);

    /**

     * Initializes the memory at address {@code (this + offset)}. Both the base address and offset

     * are in bytes. The memory must be uninitialized or zero prior to this operation.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void initializeLong(WordBase offset, long val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     * <p>

     * The offset is always treated as a {@link SignedWord} value. However, the static type is

     * {@link WordBase} to avoid the frequent casts of {@link UnsignedWord} values (where the caller

     * knows that the highest-order bit of the unsigned value is never used).

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeObject(WordBase offset, Object val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeByte(int offset, byte val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0

     */

    void writeChar(int offset, char val, LocationIdentity locationIdentity);

    /**

     * Writes the memory at address {@code (this + offset)}. Both the base address and offset are in

     * bytes.

     *

     * @param offset the signed offset for the memory access

     * @param locationIdentity the identity of the write

     * @param val the value to be written to memory

     *

     * @since 19.0