src/java.base/share/classes/java/lang/foreign/MemorySegment.java - master - wstartsev/jdk

src/java.base/share/classes/java/lang/foreign/MemorySegment.java
2 734 строки152 KB
Alan Bateman
8358958: (aio) AsynchronousByteChannel.read/write should throw IAE if buffer is thread-confined
13 июн 2025, 09:33
13 июн 2025, 09:339aeacf2
/*
 * Copyright (c) 2019, 2025, 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.foreign;

import jdk.internal.foreign.AbstractMemorySegmentImpl;
import jdk.internal.foreign.MemorySessionImpl;
import jdk.internal.foreign.SegmentBulkOperations;
import jdk.internal.foreign.SegmentFactories;
import jdk.internal.javac.Restricted;
import jdk.internal.reflect.CallerSensitive;
import jdk.internal.vm.annotation.ForceInline;

import java.io.UncheckedIOException;
import java.lang.foreign.ValueLayout.OfInt;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.CharBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Objects;
import java.util.Optional;
import java.util.Spliterator;
import java.util.function.Consumer;
import java.util.stream.Stream;

/**
 * A memory segment provides access to a contiguous region of memory.
 * <p>
 * There are two kinds of memory segments:
 * <ul>
 *     <li>A <em>heap segment</em> is backed by, and provides access to, a region of
 *     memory inside the Java heap (an "on-heap" region).</li>
 *     <li>A <em>native segment</em> is backed by, and provides access to, a region of
 *     memory outside the Java heap (an "off-heap" region).</li>
 * </ul>
 * Heap segments can be obtained by calling one of the {@link MemorySegment#ofArray(int[])}
 * factory methods. These methods return a memory segment backed by the on-heap region
 * that holds the specified Java array.
 * <p>
 * Native segments can be obtained by calling one of the {@link Arena#allocate(long, long)}
 * factory methods, which return a memory segment backed by a newly allocated off-heap
 * region with the given size and aligned to the given alignment constraint.
 * Alternatively, native segments can be obtained by
 * {@link FileChannel#map(MapMode, long, long, Arena) mapping} a file into a new off-heap
 * region (in some systems, this operation is sometimes referred to as {@code mmap}).
 * Segments obtained in this way are called <em>mapped</em> segments, and their contents
 * can be {@linkplain #force() persisted} and {@linkplain #load() loaded} to and from the
 * underlying memory-mapped file.
 * <p>
 * Both kinds of segments are read and written using the same methods, known as
 * <a href="#segment-deref">access operations</a>. An access operation on a memory
 * segment always and only provides access to the region for which the segment was
 * obtained.
 *
 * <h2 id="segment-characteristics">Characteristics of memory segments</h2>
 *
 * Every memory segment has an {@linkplain #address() address}, expressed as a
 * {@code long} value. The nature of a segment's address depends on the kind of the
 * segment:
 * <ul>
 * <li>The address of a heap segment is not a physical address, but rather an offset
 * within the region of memory which backs the segment. The region is inside the Java
 * heap, so garbage collection might cause the region to be relocated in physical memory
 * over time, but this is not exposed to clients of the {@code MemorySegment} API who
 * see a stable <em>virtualized</em> address for a heap segment backed by the region.
 * A heap segment obtained from one of the {@link #ofArray(int[])} factory methods has
 * an address of zero.</li>
 * <li>The address of a native segment (including mapped segments) denotes the physical
 * address of the region of memory which backs the segment.</li>
 * </ul>
 * <p>
 * Every memory segment has a {@linkplain #maxByteAlignment() maximum byte alignment},
 * expressed as a {@code long} value. The maximum alignment is always a power of two,
 * derived from the segment address, and the segment type, as explained in more detail
 * <a href="#segment-alignment">below</a>.
 * <p>
 * Every memory segment has a {@linkplain #byteSize() size}. The size of a heap segment
 * is derived from the Java array from which it is obtained. This size is predictable
 * across Java runtimes. The size of a native segment is either passed explicitly
 * (as in {@link Arena#allocate(long, long)}) or derived from a {@link MemoryLayout}
 * (as in {@link Arena#allocate(MemoryLayout)}). The size of a memory segment is typically
 * a positive number but may be <a href="#wrapping-addresses">zero</a>, but never negative.
 * <p>
 * The address and size of a memory segment jointly ensure that access operations on the
 * segment cannot fall <em>outside</em> the boundaries of the region of memory that backs
 * the segment. That is, a memory segment has <em>spatial bounds</em>.
 * <p>
 * Every memory segment is associated with a {@linkplain Scope scope}. This ensures that
 * access operations on a memory segment cannot occur when the region of memory that
 * backs the memory segment is no longer available (e.g., after the scope associated
 * with the accessed memory segment is no longer {@linkplain Scope#isAlive() alive}).
 * That is, a memory segment has <em>temporal bounds</em>.
 * <p>
 * Finally, access operations on a memory segment can be subject to additional
 * thread-confinement checks. Heap segments can be accessed from any thread.
 * Conversely, native segments can only be accessed compatibly with the
 * <a href="Arena.html#thread-confinement">confinement characteristics</a> of the arena
 * used to obtain them.
 *
 * <h2 id="segment-deref">Accessing memory segments</h2>
 *
 * A memory segment can be read or written using various access operations provided in
 * this class (e.g. {@link #get(ValueLayout.OfInt, long)}). Each access operation takes
 * a {@linkplain ValueLayout value layout}, which specifies the size and shape of the
 * value, and an offset, expressed in bytes. For instance, to read an {@code int} from
 * a segment, using {@linkplain ByteOrder#nativeOrder() default endianness}, the
 * following code can be used:
 * {@snippet lang=java :
 * MemorySegment segment = ...
 * int value = segment.get(ValueLayout.JAVA_INT, 0);
 * }
 *
 * If the value to be read is stored in memory using {@linkplain ByteOrder#BIG_ENDIAN big-endian}
 * encoding, the access operation can be expressed as follows:
 * {@snippet lang=java :
 * int value = segment.get(ValueLayout.JAVA_INT.withOrder(BIG_ENDIAN), 0);
 * }
 *
 * Access operations on memory segments are implemented using var handles. The
 * {@link ValueLayout#varHandle()} method can be used to obtain a var handle that can be
 * used to get/set values represented by the given value layout on a memory segment at
 * the given offset:
 *
 * {@snippet lang=java:
 * VarHandle intAtOffsetHandle = ValueLayout.JAVA_INT.varHandle(); // (MemorySegment, long)
 * int value = (int) intAtOffsetHandle.get(segment, 10L);          // segment.get(ValueLayout.JAVA_INT, 10L)
 * }
 *
 * Alternatively, a var handle that can be used to access an element of an {@code int}
 * array at a given logical index can be created as follows:
 *
 * {@snippet lang=java:
 * VarHandle intAtOffsetAndIndexHandle =
 *         ValueLayout.JAVA_INT.arrayElementVarHandle();             // (MemorySegment, long, long)
 * int value = (int) intAtOffsetAndIndexHandle.get(segment, 2L, 3L); // segment.get(ValueLayout.JAVA_INT, 2L + (3L * 4L))
 * }
 *
 * <p>
 * Clients can also drop the base offset parameter, in order to make the access
 * expression simpler. This can be used to implement access operations such as
 * {@link #getAtIndex(OfInt, long)}:
 *
 * {@snippet lang=java:
 * VarHandle intAtIndexHandle =
 *         MethodHandles.insertCoordinates(intAtOffsetAndIndexHandle, 1, 0L); // (MemorySegment, long)
 * int value = (int) intAtIndexHandle.get(segment, 3L);                       // segment.getAtIndex(ValueLayout.JAVA_INT, 3L);
 * }
 *
 * Var handles for more complex access expressions (e.g. struct field access, pointer
 * dereference) can be created directly from memory layouts, using
 * <a href="MemoryLayout.html#layout-paths"><em>layout paths</em></a>.
 *
 * <h2 id="slicing">Slicing memory segments</h2>
 *
 * Memory segments support {@linkplain MemorySegment#asSlice(long, long) slicing}.
 * Slicing a memory segment returns a new memory segment that is backed by the same
 * region of memory as the original. The address of the sliced segment is derived from
 * the address of the original segment, by adding an offset (expressed in bytes). The
 * size of the sliced segment is either derived implicitly (by subtracting the specified
 * offset from the size of the original segment), or provided explicitly. In other words,
 * a sliced segment has <em>stricter</em> spatial bounds than those of the original
 * segment:
 * {@snippet lang = java:
 * Arena arena = ...
 * MemorySegment segment = arena.allocate(100);
 * MemorySegment slice = segment.asSlice(50, 10);
 * slice.get(ValueLayout.JAVA_INT, 20); // Out of bounds!
 * arena.close();
 * slice.get(ValueLayout.JAVA_INT, 0); // Already closed!
 *}
 * The above code creates a native segment that is 100 bytes long; then, it creates a
 * slice that starts at offset 50 of {@code segment}, and is 10 bytes long. That is, the
 * address of the {@code slice} is {@code segment.address() + 50}, and its size is 10.
 * As a result, attempting to read an int value at offset 20 of the {@code slice} segment
 * will result in an exception. The {@linkplain Arena temporal bounds} of the original
 * segment is inherited by its slices; that is, when the scope associated with
 * {@code segment} is no longer {@linkplain Scope#isAlive() alive}, {@code slice} will
 * also become inaccessible.
 * <p>
 * A client might obtain a {@link Stream} from a segment, which can then be used to slice
 * the segment (according to a given element layout) and even allow multiple threads to
 * work in parallel on disjoint segment slices (to do this, the segment has to be
 * {@linkplain MemorySegment#isAccessibleBy(Thread) accessible} from multiple threads).
 * The following code can be used to sum all int values in a memory segment in parallel:
 *
 * {@snippet lang = java:
 * try (Arena arena = Arena.ofShared()) {
 *     SequenceLayout SEQUENCE_LAYOUT = MemoryLayout.sequenceLayout(1024, ValueLayout.JAVA_INT);
 *     MemorySegment segment = arena.allocate(SEQUENCE_LAYOUT);
 *     int sum = segment.elements(ValueLayout.JAVA_INT).parallel()
 *                      .mapToInt(s -> s.get(ValueLayout.JAVA_INT, 0))
 *                      .sum();
 * }
 *}
 *
 * <h2 id="segment-alignment">Alignment</h2>
 *
 * Access operations on a memory segment are constrained not only by the spatial and
 * temporal bounds of the segment, but also by the <em>alignment constraint</em> of the
 * value layout specified to the operation. An access operation can access only those
 * offsets in the segment that denote addresses in physical memory that are
 * <em>aligned</em> according to the layout. An address in physical memory is
 * <em>aligned</em> according to a layout if the address is an integer multiple of
 * the layout's alignment constraint. For example, the address 1000 is aligned according
 * to an 8-byte alignment constraint (because 1000 is an integer multiple of 8), and to
 * a 4-byte alignment constraint, and to a 2-byte alignment constraint; in contrast,
 * the address 1004 is aligned according to a 4-byte alignment constraint, and to
 * a 2-byte alignment constraint, but not to an 8-byte alignment constraint.
 * Access operations are required to respect alignment because it can impact
 * the performance of access operations, and can also determine which access operations
 * are available at a given physical address. For instance,
 * {@linkplain java.lang.invoke.VarHandle#compareAndSet(Object...) atomic access operations}
 * operations using {@link java.lang.invoke.VarHandle} are only permitted at aligned
 * addresses. In addition, alignment applies to an access operation whether the segment
 * being accessed is a native segment or a heap segment.
 * <p>
 * If the segment being accessed is a native segment, then its
 * {@linkplain #address() address} in physical memory can be combined with the offset to
 * obtain the <em>target address</em> in physical memory. The pseudo-function below
 * demonstrates this:
 *
 * {@snippet lang = java:
 * boolean isAligned(MemorySegment segment, long offset, MemoryLayout layout) {
 *   return ((segment.address() + offset) % layout.byteAlignment()) == 0;
 * }
 * }
 *
 * For example:
 * <ul>
 * <li>A native segment with address 1000 can be accessed at offsets 0, 8, 16, 24, etc
 *     under an 8-byte alignment constraint, because the target addresses
 *     (1000, 1008, 1016, 1024) are 8-byte aligned.
 *     Access at offsets 1-7 or 9-15 or 17-23 is disallowed because the target addresses
 *     would not be 8-byte aligned.</li>
 * <li>A native segment with address 1000 can be accessed at offsets 0, 4, 8, 12, etc
 *     under a 4-byte alignment constraint, because the target addresses
 *     (1000, 1004, 1008, 1012) are 4-byte aligned.
 *     Access at offsets 1-3 or 5-7 or 9-11 is disallowed because the target addresses
 *     would not be 4-byte aligned.</li>
 * <li>A native segment with address 1000 can be accessed at offsets 0, 2, 4, 6, etc
 *     under a 2-byte alignment constraint, because the target addresses
 *     (1000, 1002, 1004, 1006) are 2-byte aligned.
 *     Access at offsets 1 or 3 or 5 is disallowed because the target addresses would
 *     not be 2-byte aligned.</li>
 * <li>A native segment with address 1004 can be accessed at offsets 0, 4, 8, 12, etc
 *     under a 4-byte alignment constraint, and at offsets 0, 2, 4, 6, etc
 *     under a 2-byte alignment constraint. Under an 8-byte alignment constraint,
 *     it can be accessed at offsets 4, 12, 20, 28, etc.</li>
 * <li>A native segment with address 1006 can be accessed at offsets 0, 2, 4, 6, etc
 *     under a 2-byte alignment constraint.
 *     Under a 4-byte alignment constraint, it can be accessed at offsets 2, 6, 10, 14, etc.
 *     Under an 8-byte alignment constraint, it can be accessed at offsets 2, 10, 18, 26, etc.
 * <li>A native segment with address 1007 can be accessed at offsets 0, 1, 2, 3, etc
 *     under a 1-byte alignment constraint.
 *     Under a 2-byte alignment constraint, it can be accessed at offsets 1, 3, 5, 7, etc.
 *     Under a 4-byte alignment constraint, it can be accessed at offsets 1, 5, 9, 13, etc.
 *     Under an 8-byte alignment constraint, it can be accessed at offsets 1, 9, 17, 25, etc.</li>
 * </ul>
 * <p>
 * The alignment constraint used to access a segment is typically dictated by the shape
 * of the data structure stored in the segment. For example, if the programmer wishes to
 * store a sequence of 8-byte values in a native segment, then the segment should be
 * allocated by specifying an 8-byte alignment constraint, either via
 * {@link Arena#allocate(long, long)} or {@link Arena#allocate(MemoryLayout)}. These
 * factories ensure that the off-heap region of memory backing the returned segment
 * has a starting address that is 8-byte aligned. Subsequently, the programmer can access
 * the segment at the offsets of interest -- 0, 8, 16, 24, etc -- in the knowledge that
 * every such access is aligned.
 * <p>
 * If the segment being accessed is a heap segment, then determining whether access is
 * aligned is more complex. The address of the segment in physical memory is not known
 * and is not even fixed (it may change when the segment is relocated during garbage
 * collection). This means that the address cannot be combined with the specified offset
 * to determine a target address in physical memory. Since the alignment constraint
 * <em>always</em> refers to alignment of addresses in physical memory, it is not
 * possible in principle to determine if any offset in a heap segment is aligned.
 * For example, suppose the programmer chooses an 8-byte alignment constraint and tries
 * to access offset 16 in a heap segment. If the heap segment's address 0 corresponds to
 * physical address 1000, then the target address (1016) would be aligned, but if
 * address 0 corresponds to physical address 1004, then the target address (1020) would
 * not be aligned. It is undesirable to allow access to target addresses that are
 * aligned according to the programmer's chosen alignment constraint, but might not be
 * predictably aligned in physical memory (e.g. because of platform considerations
 * and/or garbage collection behavior).
 * <p>
 * In practice, the Java runtime lays out arrays in memory so that each n-byte element
 * occurs at an n-byte aligned physical address. The
 * runtime preserves this invariant even if the array is relocated during garbage
 * collection. Access operations rely on this invariant to determine if the specified
 * offset in a heap segment refers to an aligned address in physical memory.
 * For example:
 * <ul>
 * <li>The starting physical address of a {@code short[]} array will be 2-byte aligned
 *     (e.g. 1006) so that successive short elements occur at 2-byte aligned addresses
 *     (e.g. 1006, 1008, 1010, 1012, etc). A heap segment backed by a {@code short[]}
 *     array can be accessed at offsets 0, 2, 4, 6, etc under a 2-byte alignment
 *     constraint. The segment cannot be accessed at <em>any</em> offset under a 4-byte
 *     alignment constraint, because there is no guarantee that the target address would
 *     be 4-byte aligned, e.g., offset 0 would correspond to physical address 1006 while
 *     offset 1 would correspond to physical address 1007. Similarly, the segment cannot
 *     be accessed at any offset under an 8-byte alignment constraint, because there is
 *     no guarantee that the target address would be 8-byte aligned, e.g., offset 2
 *     would correspond to physical address 1008 but offset 4 would correspond to
 *     physical address 1010.</li>
 * <li>The starting physical address of a {@code long[]} array will be 8-byte aligned
 *     (e.g. 1000), so that successive long elements occur at 8-byte aligned addresses
 *     (e.g., 1000, 1008, 1016, 1024, etc.) A heap segment backed by a {@code long[]}
 *     array can be accessed at offsets 0, 8, 16, 24, etc under an 8-byte alignment
 *     constraint. In addition, the segment can be accessed at offsets 0, 4, 8, 12,
 *     etc under a 4-byte alignment constraint, because the target addresses (1000, 1004,
 *     1008, 1012) are 4-byte aligned. And, the segment can be accessed at offsets 0, 2,
 *     4, 6, etc under a 2-byte alignment constraint, because the target addresses (e.g.
 *     1000, 1002, 1004, 1006) are 2-byte aligned.</li>
 * </ul>
 * <p>
 * In other words, heap segments feature a <em>maximum</em>
 * alignment which is derived from the size of the elements of the Java array backing the
 * segment, as shown in the following table:
 *
 * <blockquote><table class="plain">
 * <caption style="display:none">Maximum alignment of heap segments</caption>
 * <thead>
 * <tr>
 *     <th scope="col">Array type (of backing region)</th>
 *     <th scope="col">Maximum supported alignment (in bytes)</th>
 * </tr>
 * </thead>
 * <tbody>
 * <tr><th scope="row" style="font-weight:normal">{@code boolean[]}</th>
 *     <td style="text-align:center;">{@code ValueLayout.JAVA_BOOLEAN.byteAlignment()}</td></tr>
 * <tr><th scope="row" style="font-weight:normal">{@code byte[]}</th>
 *     <td style="text-align:center;">{@code ValueLayout.JAVA_BYTE.byteAlignment()}</td></tr>
 * <tr><th scope="row" style="font-weight:normal">{@code char[]}</th>
 *     <td style="text-align:center;">{@code ValueLayout.JAVA_CHAR.byteAlignment()}</td></tr>
 * <tr><th scope="row" style="font-weight:normal">{@code short[]}</th>
 *     <td style="text-align:center;">{@code ValueLayout.JAVA_SHORT.byteAlignment()}</td></tr>
 * <tr><th scope="row" style="font-weight:normal">{@code int[]}</th>
 *     <td style="text-align:center;">{@code ValueLayout.JAVA_INT.byteAlignment()}</td></tr>
 * <tr><th scope="row" style="font-weight:normal">{@code float[]}</th>
 *     <td style="text-align:center;">{@code ValueLayout.JAVA_FLOAT.byteAlignment()}</td></tr>
 * <tr><th scope="row" style="font-weight:normal">{@code long[]}</th>
 *     <td style="text-align:center;">{@code ValueLayout.JAVA_LONG.byteAlignment()}</td></tr>
 * <tr><th scope="row" style="font-weight:normal">{@code double[]}</th>
 *     <td style="text-align:center;">{@code ValueLayout.JAVA_DOUBLE.byteAlignment()}</td></tr>
 * </tbody>
 * </table></blockquote>
 *
 * Heap segments can only be accessed using a layout whose alignment is smaller or equal
 * to the maximum alignment associated with the heap segment. Attempting to access a
 * heap segment using a layout whose alignment is greater than the maximum alignment
 * associated with the heap segment will fail, as demonstrated in the following example:
 *
 * {@snippet lang=java :
 * MemorySegment byteSegment = MemorySegment.ofArray(new byte[10]);
 * byteSegment.get(ValueLayout.JAVA_INT, 0); // fails: ValueLayout.JAVA_INT.byteAlignment() > ValueLayout.JAVA_BYTE.byteAlignment()
 * }
 *
 * In such circumstances, clients have two options. They can use a heap segment backed
 * by a different array type (e.g. {@code long[]}), capable of supporting greater maximum
 * alignment. More specifically, the maximum alignment associated with {@code long[]} is
 * set to {@code ValueLayout.JAVA_LONG.byteAlignment()}, which is 8 bytes:
 *
 * {@snippet lang=java :
 * MemorySegment longSegment = MemorySegment.ofArray(new long[10]);
 * longSegment.get(ValueLayout.JAVA_INT, 0); // ok: ValueLayout.JAVA_INT.byteAlignment() <= ValueLayout.JAVA_LONG.byteAlignment()
 * }
 *
 * Alternatively, they can invoke the access operation with an <em>unaligned layout</em>.
 * All unaligned layout constants (e.g. {@link ValueLayout#JAVA_INT_UNALIGNED}) have
 * their alignment constraint set to 1:
 * {@snippet lang=java :
 * MemorySegment byteSegment = MemorySegment.ofArray(new byte[10]);
 * byteSegment.get(ValueLayout.JAVA_INT_UNALIGNED, 0); // ok: ValueLayout.JAVA_INT_UNALIGNED.byteAlignment() == ValueLayout.JAVA_BYTE.byteAlignment()
 * }
 *
 * Clients can use the {@linkplain MemorySegment#maxByteAlignment()} method to check if
 * a memory segment supports the alignment constraint of a memory layout, as follows:
 * {@snippet lang=java:
 * MemoryLayout layout = ...
 * MemorySegment segment = ...
 * boolean isAligned = segment.maxByteAlignment() >= layout.byteAlignment();
 * }
 *
 * <h2 id="wrapping-addresses">Zero-length memory segments</h2>
 *
 * When interacting with <a href="package-summary.html#ffa">foreign functions</a>, it is
 * common for those functions to allocate a region of memory and return a pointer to that
 * region. Modeling the region of memory with a memory segment is challenging because
 * the Java runtime has no insight into the size of the region. Only the address of the
 * start of the region, stored in the pointer, is available. For example, a C function
 * with return type {@code char*} might return a pointer to a region containing a single
 * {@code char} value, or to a region containing an array of {@code char} values, where
 * the size of the array might be provided in a separate parameter. The size of the
 * array is not readily apparent to the code calling the foreign function and hoping to
 * use its result. In addition to having no insight into the size of the region of
 * memory backing a pointer returned from a foreign function, it also has no insight
 * into the lifetime intended for said region of memory by the foreign function that
 * allocated it.
 * <p>
 * The {@code MemorySegment} API uses <em>zero-length memory segments</em> to represent:
 * <ul>
 *     <li>pointers <a href="Linker.html#by-ref">returned from a foreign function</a>;</li>
 *     <li>pointers <a href="Linker.html#function-pointers">passed by a foreign function
 *         to an upcall stub</a>; and</li>
 *     <li>pointers read from a memory segment (more on that below).</li>
 * </ul>
 * The address of the zero-length segment is the address stored in the pointer.
 * The spatial and temporal bounds of the zero-length segment are as follows:
 * <ul>
 *     <li>The size of the segment is zero. Any attempt to access these segments will
 *     fail with {@link IndexOutOfBoundsException}. This is a crucial safety feature: as
 *     these segments are associated with a region of memory whose size is not known, any
 *     access operations involving these segments cannot be validated. In effect, a
 *     zero-length memory segment <em>wraps</em> an address, and it cannot be used
 *     without explicit intent (see below);</li>
 *     <li>The segment is associated with the global scope. Thus, while zero-length
 *     memory segments cannot be accessed directly, they can be passed, opaquely, to
 *     other pointer-accepting foreign functions.</li>
 * </ul>
 * <p>
 * To demonstrate how clients can work with zero-length memory segments, consider the
 * case of a client that wants to read a pointer from some memory segment. This can be
 * done via the {@linkplain MemorySegment#get(AddressLayout, long)} access method. This
 * method accepts an {@linkplain AddressLayout address layout}
 * (e.g. {@link ValueLayout#ADDRESS}), the layout of the pointer to be read. For instance,
 * on a 64-bit platform, the size of an address layout is 8 bytes. The access operation
 * also accepts an offset, expressed in bytes, which indicates the position (relative to
 * the start of the memory segment) at which the pointer is stored. The access operation
 * returns a zero-length native memory segment, backed by a region
 * of memory whose starting address is the 64-bit value read at the specified offset.
 * <p>
 * The returned zero-length memory segment cannot be accessed directly by the client:
 * since the size of the segment is zero, any access operation would result in
 * out-of-bounds access. Instead, the client must, <em>unsafely</em>, assign new spatial
 * bounds to the zero-length memory segment. This can be done via the
 * {@link #reinterpret(long)} method, as follows:
 *
 * {@snippet lang = java:
 * MemorySegment z = segment.get(ValueLayout.ADDRESS, ...);   // size = 0
 * MemorySegment ptr = z.reinterpret(16);                     // size = 16
 * int x = ptr.getAtIndex(ValueLayout.JAVA_INT, 3);           // ok
 *}
 * <p>
 * In some cases, the client might additionally want to assign new temporal bounds to a
 * zero-length memory segment. This can be done via the
 * {@link #reinterpret(long, Arena, Consumer)} method, which returns a new native segment
 * with the desired size and the same temporal bounds as those of the provided arena:
 *
 * {@snippet lang = java:
 * MemorySegment ptr = null;
 * try (Arena arena = Arena.ofConfined()) {
 *       MemorySegment z = segment.get(ValueLayout.ADDRESS, ...);    // size = 0, scope = always alive
 *       ptr = z.reinterpret(16, arena, null);                       // size = 16, scope = arena.scope()
 *       int x = ptr.getAtIndex(ValueLayout.JAVA_INT, 3);            // ok
 * }
 * int x = ptr.getAtIndex(ValueLayout.JAVA_INT, 3);                  // throws IllegalStateException
 *}
 *
 * Alternatively, if the size of the region of memory backing the zero-length memory
 * segment is known statically, the client can overlay a
 * {@linkplain AddressLayout#withTargetLayout(MemoryLayout) target layout} on the address
 * layout used when reading a pointer. The target layout is then used to dynamically
 * <em>expand</em> the size of the native memory segment returned by the access operation
 * so that the size of the segment is the same as the size of the target layout . In other
 * words, the returned segment is no longer a zero-length memory segment, and the pointer
 * it represents can be dereferenced directly:
 *
 * {@snippet lang = java:
 * AddressLayout intArrPtrLayout = ValueLayout.ADDRESS.withTargetLayout(
 *         MemoryLayout.sequenceLayout(4, ValueLayout.JAVA_INT)); // layout for int (*ptr)[4]
 * MemorySegment ptr = segment.get(intArrPtrLayout, ...);         // size = 16
 * int x = ptr.getAtIndex(ValueLayout.JAVA_INT, 3);               // ok
 *}
 * <p>
 * All the methods that can be used to manipulate zero-length memory segments
 * ({@link #reinterpret(long)}, {@link #reinterpret(Arena, Consumer)}, {@link #reinterpret(long, Arena, Consumer)} and
 * {@link AddressLayout#withTargetLayout(MemoryLayout)}) are
 * <a href="{@docRoot}/java.base/java/lang/doc-files/RestrictedMethods.html#restricted"><em>restricted</em></a> methods, and should
 * be used with caution: assigning a segment incorrect spatial and/or temporal bounds
 * could result in a VM crash when attempting to access the memory segment.
 *
 * @implSpec
 * Implementations of this interface are immutable, thread-safe and
 * <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>.
 *
 * @since 22
 */
public sealed interface MemorySegment permits AbstractMemorySegmentImpl {

    /**
     * {@return the address of this memory segment}
     *
     * @apiNote When using this method to pass a segment address to some external
     *          operation (e.g. a JNI function), clients must ensure that the segment is
     *          kept {@linkplain java.lang.ref##reachability reachable}
     *          for the entire duration of the operation. A failure to do so might result
     *          in the premature deallocation of the region of memory backing the memory
     *          segment, in case the segment has been allocated with an
     *          {@linkplain Arena#ofAuto() automatic arena}.
     */
    long address();

    /**
     * Returns the Java object stored in the on-heap region of memory backing this memory
     * segment, if any. For instance, if this memory segment is a heap segment created
     * with the {@link #ofArray(byte[])} factory method, this method will return the
     * {@code byte[]} object which was used to obtain the segment. This method returns
     * an empty {@code Optional} value if either this segment is a
     * {@linkplain #isNative() native} segment, or if this segment is
     * {@linkplain #isReadOnly() read-only}.
     *
     * @return the Java object associated with this memory segment, if any
     */
    Optional<Object> heapBase();

    /**
     * Returns a spliterator for this memory segment. The returned spliterator reports
     * {@link Spliterator#SIZED}, {@link Spliterator#SUBSIZED}, {@link Spliterator#IMMUTABLE},
     * {@link Spliterator#NONNULL} and {@link Spliterator#ORDERED} characteristics.
     * <p>
     * The returned spliterator splits this segment according to the specified element
     * layout; that is, if the supplied layout has size N, then calling
     * {@link Spliterator#trySplit()} will result in a spliterator serving approximately
     * {@code S/N} elements (depending on whether N is even or not), where {@code S} is
     * the size of this segment. As such, splitting is possible as long as
     * {@code S/N >= 2}. The spliterator returns segments that have the same lifetime as
     * that of this segment.
     * <p>
     * The returned spliterator effectively allows to slice this segment into disjoint
     * {@linkplain #asSlice(long, long) slices}, which can then be processed in parallel
     * by multiple threads.
     *
     * @param elementLayout the layout to be used for splitting
     * @return the element spliterator for this segment
     * @throws IllegalArgumentException if {@code elementLayout.byteSize() == 0}
     * @throws IllegalArgumentException if {@code byteSize() % elementLayout.byteSize() != 0}
     * @throws IllegalArgumentException if {@code elementLayout.byteSize() % elementLayout.byteAlignment() != 0}
     * @throws IllegalArgumentException if this segment is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout.
     */
    Spliterator<MemorySegment> spliterator(MemoryLayout elementLayout);

    /**
     * Returns a sequential {@code Stream} over disjoint slices (whose size matches that
     * of the specified layout) in this segment. Calling this method is equivalent to
     * the following code:
     * {@snippet lang=java :
     * StreamSupport.stream(segment.spliterator(elementLayout), false);
     * }
     *
     * @param elementLayout the layout to be used for splitting
     * @return a sequential {@code Stream} over disjoint slices in this segment
     * @throws IllegalArgumentException if {@code elementLayout.byteSize() == 0}
     * @throws IllegalArgumentException if {@code byteSize() % elementLayout.byteSize() != 0}
     * @throws IllegalArgumentException if {@code elementLayout.byteSize() % elementLayout.byteAlignment() != 0}
     * @throws IllegalArgumentException if this segment is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     */
    Stream<MemorySegment> elements(MemoryLayout elementLayout);

    /**
     * {@return the scope associated with this memory segment}
     */
    Scope scope();

    /**
     * {@return {@code true} if this segment can be accessed from the provided thread}
     * @param thread the thread to be tested
     */
    boolean isAccessibleBy(Thread thread);

    /**
     * {@return the size (in bytes) of this memory segment}
     */
    long byteSize();

    /**
     * {@return the <a href="#segment-alignment">maximum byte alignment</a>
     * associated with this memory segment}
     * <p>
     * The returned alignment is always a power of two and is derived from
     * the segment {@linkplain #address() address()} and, if it is a heap segment,
     * the type of the {@linkplain #heapBase() backing heap storage}.
     * <p>
     * This method can be used to ensure that a segment is sufficiently aligned
     * with a layout:
     * {@snippet lang=java:
     * MemoryLayout layout = ...
     * MemorySegment segment = ...
     * if (segment.maxByteAlignment() < layout.byteAlignment()) {
     *     // Take action (e.g. throw an Exception)
     * }
     * }
     *
     * @since 23
     */
    long maxByteAlignment();

    /**
     * Returns a slice of this memory segment, at the given offset. The returned
     * segment's address is the address of this segment plus the given offset;
     * its size is specified by the given argument.
     * <p>
     * Equivalent to the following code:
     * {@snippet lang=java :
     * asSlice(offset, newSize, 1);
     * }
     * <p>
     * If this segment is {@linkplain MemorySegment#isReadOnly() read-only},
     * the returned segment is also {@linkplain MemorySegment#isReadOnly() read-only}.
     * <p>
     * The returned memory segment shares a region of backing memory with this segment.
     * Hence, no memory will be allocated or freed by this method.
     *
     * @see #asSlice(long, long, long)
     *
     * @param offset The new segment base offset (relative to the address of this segment),
     *               specified in bytes
     * @param newSize The new segment size, specified in bytes
     * @return a slice of this memory segment
     * @throws IndexOutOfBoundsException if {@code offset < 0}, {@code offset > byteSize()},
     *         {@code newSize < 0}, or {@code newSize > byteSize() - offset}
     */
    MemorySegment asSlice(long offset, long newSize);

    /**
     * Returns a slice of this memory segment, at the given offset, with the provided
     * alignment constraint. The returned segment's address is the address of this
     * segment plus the given offset; its size is specified by the given argument.
     * <p>
     * If this segment is {@linkplain MemorySegment#isReadOnly() read-only},
     * the returned segment is also {@linkplain MemorySegment#isReadOnly() read-only}.
     * <p>
     * The returned memory segment shares a region of backing memory with this segment.
     * Hence, no memory will be allocated or freed by this method.
     *
     * @param offset The new segment base offset (relative to the address of this segment),
     *               specified in bytes
     * @param newSize The new segment size, specified in bytes
     * @param byteAlignment The alignment constraint (in bytes) of the returned slice
     * @return a slice of this memory segment
     * @throws IndexOutOfBoundsException if {@code offset < 0}, {@code offset > byteSize()},
     *         {@code newSize < 0}, or {@code newSize > byteSize() - offset}
     * @throws IllegalArgumentException if this segment cannot be accessed at {@code offset} under
     *         the provided alignment constraint
     * @throws IllegalArgumentException if {@code byteAlignment <= 0}, or if
     *         {@code byteAlignment} is not a power of 2
     */
    MemorySegment asSlice(long offset, long newSize, long byteAlignment);

    /**
     * Returns a slice of this memory segment with the given layout, at the given offset.
     * The returned segment's address is the address of this segment plus the given
     * offset; its size is the same as the size of the provided layout.
     * <p>
     * Equivalent to the following code:
     * {@snippet lang=java :
     * asSlice(offset, layout.byteSize(), layout.byteAlignment());
     * }
     * <p>
     * If this segment is {@linkplain MemorySegment#isReadOnly() read-only},
     * the returned segment is also {@linkplain MemorySegment#isReadOnly() read-only}.
     * <p>
     * The returned memory segment shares a region of backing memory with this segment.
     * Hence, no memory will be allocated or freed by this method.
     *
     * @see #asSlice(long, long, long)
     *
     * @param offset The new segment base offset (relative to the address of this segment),
     *               specified in bytes
     * @param layout The layout of the segment slice
     * @throws IndexOutOfBoundsException if {@code offset < 0}, {@code offset > byteSize()},
     *         or {@code layout.byteSize() > byteSize() - offset}
     * @throws IllegalArgumentException if this segment cannot be accessed at {@code offset}
     *         under the alignment constraint specified by {@code layout}
     * @return a slice of this memory segment
     */
    MemorySegment asSlice(long offset, MemoryLayout layout);

    /**
     * Returns a slice of this memory segment, at the given offset. The returned
     * segment's address is the address of this segment plus the given offset; its size
     * is computed by subtracting the specified offset from this segment size.
     * <p>
     * Equivalent to the following code:
     * {@snippet lang=java :
     * asSlice(offset, byteSize() - offset);
     * }
     * <p>
     * If this segment is {@linkplain MemorySegment#isReadOnly() read-only},
     * the returned segment is also {@linkplain MemorySegment#isReadOnly() read-only}.
     * <p>
     * The returned memory segment shares a region of backing memory with this segment.
     * Hence, no memory will be allocated or freed by this method.
     *
     * @see #asSlice(long, long)
     *
     * @param offset The new segment base offset (relative to the address of this segment),
     *               specified in bytes
     * @return a slice of this memory segment
     * @throws IndexOutOfBoundsException if {@code offset < 0}, or {@code offset > byteSize()}
     */
    MemorySegment asSlice(long offset);

    /**
     * Returns a new memory segment that has the same address and scope as this segment,
     * but with the provided size.
     * <p>
     * If this segment is {@linkplain MemorySegment#isReadOnly() read-only},
     * the returned segment is also {@linkplain MemorySegment#isReadOnly() read-only}.
     * <p>
     * The returned memory segment shares a region of backing memory with this segment.
     * Hence, no memory will be allocated or freed by this method.
     *
     * @param newSize the size of the returned segment
     * @return a new memory segment that has the same address and scope as
     *         this segment, but the new provided size
     * @throws IllegalArgumentException if {@code newSize < 0}
     * @throws UnsupportedOperationException if this segment is not a
     *         {@linkplain #isNative() native} segment
     * @throws IllegalCallerException if the caller is in a module that does not have
     *         native access enabled
     */
    @CallerSensitive
    @Restricted
    MemorySegment reinterpret(long newSize);

    /**
     * Returns a new memory segment with the same address and size as this segment, but
     * with the provided arena's scope. As such, the returned segment cannot be accessed
     * after the provided arena has been closed. Moreover, the returned segment can be
     * accessed compatibly with the confinement restrictions associated with the provided
     * arena: that is, if the provided arena is a {@linkplain Arena#ofConfined() confined arena},
     * the returned segment can only be accessed by the arena's owner thread, regardless
     * of the confinement restrictions associated with this segment. In other words, this
     * method returns a segment that can be used as any other segment allocated using the
     * provided arena. However, the returned segment is backed by the same memory region
     * as that of the original segment. As such, the region of memory backing the
     * returned segment is deallocated only when this segment's arena is closed.
     * This might lead to <em>use-after-free</em> issues, as the returned segment can be
     * accessed <em>after</em> its region of memory has been deallocated via this
     * segment's arena.
     * <p>
     * Clients can specify an optional cleanup action that should be executed when the
     * provided arena's scope becomes invalid. This cleanup action receives a fresh memory
     * segment that is obtained from this segment as follows:
     * {@snippet lang=java :
     * MemorySegment cleanupSegment = MemorySegment.ofAddress(this.address())
     *                                             .reinterpret(byteSize());
     * }
     * That is, the cleanup action receives a segment that is associated with the global
     * arena's scope, and is accessible from any thread. The size of the segment accepted
     * by the cleanup action is {@link #byteSize()}.
     * <p>
     * If this segment is {@linkplain MemorySegment#isReadOnly() read-only},
     * the returned segment is also {@linkplain MemorySegment#isReadOnly() read-only}.
     * <p>
     * The returned memory segment shares a region of backing memory with this segment.
     * Hence, no memory will be allocated or freed by this method.
     *
     * @apiNote The cleanup action (if present) should take care not to leak the received
     *          segment to external clients that might access the segment after its
     *          backing region of memory is no longer available. Furthermore, if the
     *          provided arena is an {@linkplain Arena#ofAuto() automatic arena},
     *          the cleanup action must not prevent the arena from becoming
     *          {@linkplain java.lang.ref##reachability unreachable}.
     *          A failure to do so will permanently prevent the regions of memory
     *          allocated by the automatic arena from being deallocated.
     *
     * @param arena the arena to be associated with the returned segment
     * @param cleanup the cleanup action that should be executed when the provided arena
     *                is closed (can be {@code null})
     * @return a new memory segment with unbounded size
     * @throws IllegalStateException if {@code arena.scope().isAlive() == false}
     * @throws UnsupportedOperationException if this segment is not a
     *         {@linkplain #isNative() native} segment
     * @throws IllegalCallerException if the caller is in a module that does not have
     *         native access enabled
     */
    @CallerSensitive
    @Restricted
    MemorySegment reinterpret(Arena arena, Consumer<MemorySegment> cleanup);

    /**
     * Returns a new segment with the same address as this segment, but with the provided
     * size and the provided arena's scope. As such, the returned segment cannot be
     * accessed after the provided arena has been closed. Moreover, if the returned
     * segment can be accessed compatibly with the confinement restrictions associated
     * with the provided arena: that is, if the provided arena is a {@linkplain Arena#ofConfined() confined arena},
     * the returned segment can only be accessed by the arena's owner thread, regardless
     * of the confinement restrictions associated with this segment. In other words, this
     * method returns a segment that can be used as any other segment allocated using the
     * provided arena. However, the returned segment is backed by the same memory region
     * as that of the original segment. As such, the region of memory backing the
     * returned segment is deallocated only when this segment's arena is closed.
     * This might lead to <em>use-after-free</em> issues, as the returned segment can be
     * accessed <em>after</em> its region of memory has been deallocated via this
     * segment's arena.
     * <p>
     * Clients can specify an optional cleanup action that should be executed when the
     * provided arena's scope becomes invalid. This cleanup action receives a fresh memory
     * segment that is obtained from this segment as follows:
     * {@snippet lang=java :
     * MemorySegment cleanupSegment = MemorySegment.ofAddress(this.address())
     *                                             .reinterpret(newSize);
     * }
     * That is, the cleanup action receives a segment that is associated with the global
     * arena's scope, and is accessible from any thread. The size of the segment accepted
     * by the cleanup action is {@code newSize}.
     * <p>
     * If this segment is {@linkplain MemorySegment#isReadOnly() read-only},
     * the returned segment is also {@linkplain MemorySegment#isReadOnly() read-only}.
     * <p>
     * The returned memory segment shares a region of backing memory with this segment.
     * Hence, no memory will be allocated or freed by this method.
     *
     * @apiNote The cleanup action (if present) should take care not to leak the received
     *          segment to external clients that might access the segment after its
     *          backing region of memory is no longer available. Furthermore, if the
     *          provided arena is an {@linkplain Arena#ofAuto() automatic arena},
     *          the cleanup action must not prevent the arena from becoming
     *          {@linkplain java.lang.ref##reachability unreachable}.
     *          A failure to do so will permanently prevent the regions of memory
     *          allocated by the automatic arena from being deallocated.
     *
     * @param newSize the size of the returned segment
     * @param arena the arena to be associated with the returned segment
     * @param cleanup the cleanup action that should be executed when the provided arena
     *                is closed (can be {@code null}).
     * @return a new segment that has the same address as this segment, but with the new
     *         size and its scope set to that of the provided arena.
     * @throws UnsupportedOperationException if this segment is not a
     *         {@linkplain #isNative() native} segment
     * @throws IllegalArgumentException if {@code newSize < 0}
     * @throws IllegalStateException if {@code arena.scope().isAlive() == false}
     * @throws IllegalCallerException if the caller is in a module that does not have
     *         native access enabled
     */
    @CallerSensitive
    @Restricted
    MemorySegment reinterpret(long newSize,
                              Arena arena,
                              Consumer<MemorySegment> cleanup);

    /**
     * {@return {@code true}, if this segment is read-only}
     * @see #asReadOnly()
     */
    boolean isReadOnly();

    /**
     * {@return a read-only view of this segment}
     *
     * The resulting segment will be identical to this one, but attempts to overwrite the
     * contents of the returned segment will cause runtime exceptions.
     *
     * @see #isReadOnly()
     */
    MemorySegment asReadOnly();

    /**
     * {@return {@code true} if this segment is a native segment}
     * <p>
     * A native segment is created e.g. using the {@link Arena#allocate(long, long)}
     * (and related) factory, or by {@linkplain #ofBuffer(Buffer) wrapping} a
     * {@linkplain ByteBuffer#allocateDirect(int) direct buffer}.
     */
    boolean isNative();

    /**
     * {@return {@code true} if this segment is a mapped segment}
     *
     * A mapped memory segment is created e.g. using the
     * {@link FileChannel#map(FileChannel.MapMode, long, long, Arena)} factory, or by
     * {@linkplain #ofBuffer(Buffer) wrapping} a
     * {@linkplain java.nio.MappedByteBuffer mapped byte buffer}.
     */
    boolean isMapped();

    /**
     * Returns a slice of this segment that is the overlap between this and the provided
     * segment.
     *
     * <p>Two segments {@code S1} and {@code S2} are said to overlap if it is possible to
     * find at least two slices {@code L1} (from {@code S1}) and {@code L2}
     * (from {@code S2}) that are backed by the same region of memory. As such, it is
     * not possible for a {@linkplain #isNative() native} segment to overlap with a heap
     * segment; in this case, or when no overlap occurs, an empty {@code Optional} is
     * returned.
     *
     * @param other the segment to test for an overlap with this segment
     * @return a slice of this segment (where overlapping occurs)
     */
    Optional<MemorySegment> asOverlappingSlice(MemorySegment other);

    /**
     * Fills the contents of this memory segment with the given value.
     * <p>
     * More specifically, the given value is written into each address of this
     * segment. Equivalent to (but likely more efficient than) the following code:
     *
     * {@snippet lang=java :
     * for (long offset = 0; offset < segment.byteSize(); offset++) {
     *     segment.set(ValueLayout.JAVA_BYTE, offset, value);
     * }
     * }
     *
     * But without any regard or guarantees on the ordering of particular memory
     * elements being set.
     * <p>
     * This method can be useful to initialize or reset the contents of a memory segment.
     *
     * @param value the value to write into this segment
     * @return this memory segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    MemorySegment fill(byte value);

    /**
     * Performs a bulk copy from the given source segment to this segment. More specifically,
     * the bytes at offset {@code 0} through {@code src.byteSize() - 1} in the source
     * segment are copied into this segment at offset {@code 0} through
     * {@code src.byteSize() - 1}.
     * <p>
     * Calling this method is equivalent to the following code:
     * {@snippet lang=java :
     * MemorySegment.copy(src, 0, this, 0, src.byteSize());
     * }
     * @param src the source segment
     * @throws IndexOutOfBoundsException if {@code src.byteSize() > this.byteSize()}
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code src} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code src.isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     * @return this segment
     */
    MemorySegment copyFrom(MemorySegment src);

    /**
     * Finds and returns the offset, in bytes, of the first mismatch between
     * this segment and the given other segment. The offset is relative to the
     * {@linkplain #address() address} of each segment and will be in the
     * range of 0 (inclusive) up to the {@linkplain #byteSize() size} (in bytes) of
     * the smaller memory segment (exclusive).
     * <p>
     * If the two segments share a common prefix then the returned offset is
     * the length of the common prefix, and it follows that there is a mismatch
     * between the two segments at that offset within the respective segments.
     * If one segment is a proper prefix of the other, then the returned offset is
     * the smallest of the segment sizes, and it follows that the offset is only
     * valid for the larger segment. Otherwise, there is no mismatch and {@code
     * -1} is returned.
     *
     * @param other the segment to be tested for a mismatch with this segment
     * @return the relative offset, in bytes, of the first mismatch between this
     * and the given other segment, otherwise -1 if no mismatch
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code other} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code other.isAccessibleBy(T) == false}
     */
    long mismatch(MemorySegment other);

    /**
     * Determines whether all the contents of this mapped segment are resident in physical
     * memory.
     *
     * <p> A return value of {@code true} implies that it is highly likely
     * that all the data in this segment is resident in physical memory and
     * may therefore be accessed without incurring any virtual-memory page
     * faults or I/O operations. A return value of {@code false} does not
     * necessarily imply that this segment's contents are not resident in physical
     * memory.
     *
     * <p> The returned value is a hint, rather than a guarantee, because the
     * underlying operating system may have paged out some of this segment's data
     * by the time that an invocation of this method returns.  </p>
     *
     * @return  {@code true} if it is likely that the contents of this segment
     *          are resident in physical memory
     *
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws UnsupportedOperationException if this segment is not a mapped memory
     *         segment, e.g. if {@code isMapped() == false}
     */
    boolean isLoaded();

    /**
     * Loads the contents of this mapped segment into physical memory.
     * <p>
     * This method makes a best effort to ensure that, when it returns,
     * the contents of this segment are resident in physical memory.  Invoking this
     * method may cause some number of page faults and I/O operations to
     * occur. </p>
     *
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread
     *         {@code T}, such that {@code isAccessibleBy(T) == false}
     * @throws UnsupportedOperationException if this segment is not a mapped memory
     *         segment, e.g. if {@code isMapped() == false}
     */
    void load();

    /**
     * Unloads the contents of this mapped segment from physical memory.
     * <p>
     * This method makes a best effort to ensure that the contents of this segment
     * are no longer resident in physical memory. Accessing this segment's contents
     * after invoking this method may cause some number of page faults and I/O operations
     * to occur (as this segment's contents might need to be paged back in). </p>
     *
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws UnsupportedOperationException if this segment is not a mapped memory
     *         segment, e.g. if {@code isMapped() == false}
     */
    void unload();

    /**
     * Forces any changes made to the contents of this mapped segment to be written to
     * the storage device described by the mapped segment's file descriptor.
     * <p>
     * If the file descriptor associated with this mapped segment resides on a local
     * storage device then when this method returns it is guaranteed that all changes
     * made to this segment since it was created, or since this method was last invoked,
     * will have been written to that device.
     * <p>
     * If the file descriptor associated with this mapped segment does not reside on
     * a local device then no such guarantee is made.
     * <p>
     * If this segment was not mapped in read/write mode
     * ({@link java.nio.channels.FileChannel.MapMode#READ_WRITE}) then invoking this
     * method may have no effect. In particular, the method has no effect for segments
     * mapped in read-only or private mapping modes. This method may or may not have an
     * effect for implementation-specific mapping modes.
     *
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with this segment is not
     *         {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws UnsupportedOperationException if this segment is not a mapped memory segment, e.g. if
     *         {@code isMapped() == false}
     * @throws UncheckedIOException if there is an I/O error writing the contents of this segment to the
     *         associated storage device
     */
    void force();

    /**
     * Wraps this segment in a {@link ByteBuffer}. Some properties of the returned buffer
     * are linked to the properties of this segment. More specifically, the resulting
     * buffer has the following characteristics:
     * <ul>
     * <li>It is {@linkplain ByteBuffer#isReadOnly() read-only}, if this segment is a
     * {@linkplain #isReadOnly() read-only segment};</li>
     * <li>Its {@linkplain ByteBuffer#position() position} is set to zero;
     * <li>Its {@linkplain ByteBuffer#capacity() capacity} and
     * {@linkplain ByteBuffer#limit() limit} are both set to this segment's
     * {@linkplain MemorySegment#byteSize() size}. For this reason, a byte buffer cannot
     * be returned if this segment's size is greater than {@link Integer#MAX_VALUE};</li>
     * <li>It is a {@linkplain ByteBuffer#isDirect() direct buffer}, if this is a
     * native segment.</li>
     * </ul>
     * <p>
     * The life-cycle of the returned buffer is tied to that of this segment. That is,
     * accessing the returned buffer after the scope associated with this segment is no
     * longer {@linkplain Scope#isAlive() alive}, will throw an
     * {@link IllegalStateException}. Similarly, accessing the returned buffer from a
     * thread {@code T} such that {@code isAccessible(T) == false} will throw a
     * {@link WrongThreadException}.
     * <p>
     * If this segment is {@linkplain #isAccessibleBy(Thread) accessible} from a single
     * thread, calling read/write I/O operations on the resulting buffer might result in
     * unspecified exceptions being thrown.
     * <p>
     * Finally, the resulting buffer's byte order is
     * {@link java.nio.ByteOrder#BIG_ENDIAN}; this can be changed using
     * {@link ByteBuffer#order(java.nio.ByteOrder)}.
     *
     * @return a {@link ByteBuffer} view of this memory segment
     * @throws UnsupportedOperationException if this segment cannot be mapped onto a
     *         {@link ByteBuffer} instance, e.g. if it is a heap segment backed by an
     *         array other than {@code byte[]}), or if its size is greater than
     *         {@link Integer#MAX_VALUE}
     */
    ByteBuffer asByteBuffer();

    /**
     * Copy the contents of this memory segment into a new byte array.
     *
     * @param elementLayout the source element layout. If the byte order associated with
     *                      the layout is different from the
     *                      {@linkplain ByteOrder#nativeOrder native order}, a byte swap
     *                      operation will be performed on each array element
     * @return a new byte array whose contents are copied from this memory segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalStateException if this segment's contents cannot be copied into a
     *         {@code byte[]} instance, e.g. its size is greater than {@link Integer#MAX_VALUE}
     */
    byte[] toArray(ValueLayout.OfByte elementLayout);

    /**
     * Copy the contents of this memory segment into a new short array.
     *
     * @param elementLayout the source element layout. If the byte order associated with
     *                      the layout is different from the
     *                      {@linkplain ByteOrder#nativeOrder native order}, a byte swap
     *                      operation will be performed on each array element
     * @return a new short array whose contents are copied from this memory segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalStateException if this segment's contents cannot be copied into a
     *         {@code short[]} instance, e.g. because {@code byteSize() % 2 != 0}, or
     *         {@code byteSize() / 2 > Integer.MAX_VALUE}
     */
    short[] toArray(ValueLayout.OfShort elementLayout);

    /**
     * Copy the contents of this memory segment into a new char array.
     *
     * @param elementLayout the source element layout. If the byte order associated with
     *                      the layout is different from the
     *                      {@linkplain ByteOrder#nativeOrder native order}, a byte swap
     *                      operation will be performed on each array element
     * @return a new char array whose contents are copied from this memory segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalStateException if this segment's contents cannot be copied into a
     *         {@code char[]} instance, e.g. because {@code byteSize() % 2 != 0}, or
     *         {@code byteSize() / 2 > Integer.MAX_VALUE}
     */
    char[] toArray(ValueLayout.OfChar elementLayout);

    /**
     * Copy the contents of this memory segment into a new int array.
     *
     * @param elementLayout the source element layout. If the byte order associated with
     *                     the layout is different from the
     *                     {@linkplain ByteOrder#nativeOrder native order}, a byte swap
     *                     operation will be performed on each array element.
     * @return a new int array whose contents are copied from this memory segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalStateException if this segment's contents cannot be copied into a
     *         {@code int[]} instance, e.g. because {@code byteSize() % 4 != 0}, or
     *         {@code byteSize() / 4 > Integer.MAX_VALUE}
     */
    int[] toArray(ValueLayout.OfInt elementLayout);

    /**
     * Copy the contents of this memory segment into a new float array.
     *
     * @param elementLayout the source element layout. If the byte order associated with
     *                      the layout is different from the
     *                      {@linkplain ByteOrder#nativeOrder native order}, a byte swap
     *                      operation will be performed on each array element
     * @return a new float array whose contents are copied from this memory segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalStateException if this segment's contents cannot be copied into a
     *         {@code float[]} instance, e.g. because {@code byteSize() % 4 != 0}, or
     *         {@code byteSize() / 4 > Integer.MAX_VALUE}
     */
    float[] toArray(ValueLayout.OfFloat elementLayout);

    /**
     * Copy the contents of this memory segment into a new long array.
     *
     * @param elementLayout the source element layout. If the byte order associated with
     *                     the layout is different from the
     *                     {@linkplain ByteOrder#nativeOrder native order}, a byte swap
     *                     operation will be performed on each array element
     * @return a new long array whose contents are copied from this memory segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalStateException if this segment's contents cannot be copied into a
     *         {@code long[]} instance, e.g. because {@code byteSize() % 8 != 0}, or
     *         {@code byteSize() / 8 > Integer.MAX_VALUE}
     */
    long[] toArray(ValueLayout.OfLong elementLayout);

    /**
     * Copy the contents of this memory segment into a new double array.
     *
     * @param elementLayout the source element layout. If the byte order associated with
     *                      the layout is different from the
     *                      {@linkplain ByteOrder#nativeOrder native order}, a byte swap
     *                      operation will be performed on each array element
     * @return a new double array whose contents are copied from this memory segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalStateException if this segment's contents cannot be copied into a
     *         {@code double[]} instance, e.g. because {@code byteSize() % 8 != 0}, or
     *         {@code byteSize() / 8 > Integer.MAX_VALUE}
     */
    double[] toArray(ValueLayout.OfDouble elementLayout);

    /**
     * Reads a null-terminated string from this segment at the given offset, using the
     * {@linkplain StandardCharsets#UTF_8 UTF-8} charset.
     * <p>
     * Calling this method is equivalent to the following code:
     * {@snippet lang = java:
     * getString(offset, StandardCharsets.UTF_8);
     *}
     *
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur
     * @return a Java string constructed from the bytes read from the given starting
     *         address up to (but not including) the first {@code '\0'} terminator
     *         character (assuming one is found)
     * @throws IllegalArgumentException if the size of the string is greater than the
     *         largest string supported by the platform
     * @throws IndexOutOfBoundsException if {@code offset < 0}
     * @throws IndexOutOfBoundsException if no string terminator (e.g. {@code '\0'}) is
     *         present in this segment between the given {@code offset} and the end of
     *         this segment.
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     */
    String getString(long offset);

    /**
     * Reads a null-terminated string from this segment at the given offset, using the
     * provided charset.
     * <p>
     * This method always replaces malformed-input and unmappable-character
     * sequences with this charset's default replacement string. The {@link
     * java.nio.charset.CharsetDecoder} class should be used when more control
     * over the decoding process is required.
     * <p>
     * Getting a string from a segment with a known byte offset and
     * known byte length can be done like so:
     * {@snippet lang=java :
     *     byte[] bytes = new byte[length];
     *     MemorySegment.copy(segment, JAVA_BYTE, offset, bytes, 0, length);
     *     return new String(bytes, charset);
     * }
     *
     * @param offset  offset in bytes (relative to this segment address) at which this
     *                access operation will occur
     * @param charset the charset used to {@linkplain Charset#newDecoder() decode} the
     *                string bytes. The {@code charset} must be a
     *                {@linkplain StandardCharsets standard charset}
     * @return a Java string constructed from the bytes read from the given starting
     *         address up to (but not including) the first {@code '\0'} terminator
     *         character (assuming one is found)
     * @throws IllegalArgumentException  if the size of the string is greater than the
     *         largest string supported by the platform
     * @throws IndexOutOfBoundsException if {@code offset < 0}
     * @throws IndexOutOfBoundsException if no string terminator (e.g. {@code '\0'}) is
     *         present in this segment between the given {@code offset} and the end of
     *         this segment. The byte size of the string terminator depends on the
     *         selected {@code charset}. For instance, this is 1 for
     *         {@link StandardCharsets#US_ASCII} and 2 for {@link StandardCharsets#UTF_16}
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if {@code charset} is not a
     *         {@linkplain StandardCharsets standard charset}
     */
    String getString(long offset, Charset charset);

    /**
     * Writes the given string into this segment at the given offset, converting it to
     * a null-terminated byte sequence using the {@linkplain StandardCharsets#UTF_8 UTF-8}
     * charset.
     * <p>
     * Calling this method is equivalent to the following code:
     * {@snippet lang = java:
     * setString(offset, str, StandardCharsets.UTF_8);
     *}
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur, the final address of this write
     *               operation can be expressed as {@code address() + offset}.
     * @param str the Java string to be written into this segment
     * @throws IndexOutOfBoundsException if {@code offset < 0}
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - (B + 1)}, where
     *         {@code B} is the size, in bytes, of the string encoded using UTF-8 charset
     *         {@code str.getBytes(StandardCharsets.UTF_8).length})
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void setString(long offset, String str);

    /**
     * Writes the given string into this segment at the given offset, converting it to a
     * null-terminated byte sequence using the provided charset.
     * <p>
     * This method always replaces malformed-input and unmappable-character
     * sequences with this charset's default replacement string. The {@link
     * java.nio.charset.CharsetDecoder} class should be used when more control
     * over the decoding process is required.
     * <p>
     * If the given string contains any {@code '\0'} characters, they will be
     * copied as well. This means that, depending on the method used to read
     * the string, such as {@link MemorySegment#getString(long)}, the string
     * will appear truncated when read again.
     *
     * @param offset  offset in bytes (relative to this segment address) at which this
     *                access operation will occur, the final address of this write
     *                operation can be expressed as {@code address() + offset}
     * @param str     the Java string to be written into this segment
     * @param charset the charset used to {@linkplain Charset#newEncoder() encode} the
     *                string bytes. The {@code charset} must be a
     *                {@linkplain StandardCharsets standard charset}
     * @throws IndexOutOfBoundsException if {@code offset < 0}
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - (B + N)}, where:
     *         <ul>
     *             <li>{@code B} is the size, in bytes, of the string encoded using the
     *             provided charset (e.g. {@code str.getBytes(charset).length});</li>
     *             <li>{@code N} is the size (in bytes) of the terminator char according
     *             to the provided charset. For instance, this is 1 for
     *             {@link StandardCharsets#US_ASCII} and 2 for {@link StandardCharsets#UTF_16}.</li>
     *         </ul>
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if {@code charset} is not a
     *         {@linkplain StandardCharsets standard charset}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void setString(long offset, String str, Charset charset);

    /**
     * Creates a memory segment that is backed by the same region of memory that backs
     * the given {@link Buffer} instance. The segment starts relative to the buffer's
     * position (inclusive) and ends relative to the buffer's limit (exclusive).
     * <p>
     * If the buffer is {@linkplain Buffer#isReadOnly() read-only}, the resulting segment
     * is also {@linkplain ByteBuffer#isReadOnly() read-only}. Moreover, if the buffer
     * is a {@linkplain Buffer#isDirect() direct buffer}, the returned segment is a
     * native segment; otherwise, the returned memory segment is a heap segment.
     * <p>
     * If the provided buffer has been obtained by calling {@link #asByteBuffer()} on a
     * memory segment whose {@linkplain Scope scope} is {@code S}, the returned segment
     * will be associated with the same scope {@code S}. Otherwise, the scope of the
     * returned segment is an automatic scope that keeps the provided buffer reachable.
     * As such, if the provided buffer is a direct buffer, its backing memory region will
     * not be deallocated as long as the returned segment, or any of its slices, are kept
     * reachable.
     *
     * @param buffer the buffer instance to be turned into a new memory segment
     * @return a memory segment, derived from the given buffer instance
     * @throws IllegalArgumentException if the provided {@code buffer} is a heap buffer
     *         but is not backed by an array; For example, buffers directly or indirectly
     *         obtained via ({@link CharBuffer#wrap(CharSequence)} or
     *         {@link CharBuffer#wrap(char[], int, int)} are not backed by an array.
     */
    static MemorySegment ofBuffer(Buffer buffer) {
        return AbstractMemorySegmentImpl.ofBuffer(buffer);
    }

    /**
     * Creates a heap segment backed by the on-heap region of memory that holds the given
     * byte array. The scope of the returned segment is an automatic scope that keeps
     * the given array reachable. The returned segment is always accessible, from any
     * thread. Its {@link #address()} is set to zero.
     *
     * @param byteArray the primitive array backing the heap memory segment
     * @return a heap memory segment backed by a byte array
     */
    static MemorySegment ofArray(byte[] byteArray) {
        return SegmentFactories.fromArray(byteArray);
    }

    /**
     * Creates a heap segment backed by the on-heap region of memory that holds the given
     * char array. The scope of the returned segment is an automatic scope that keeps
     * the given array reachable. The returned segment is always accessible, from any
     * thread. Its {@link #address()} is set to zero.
     *
     * @param charArray the primitive array backing the heap segment
     * @return a heap memory segment backed by a char array
     */
    static MemorySegment ofArray(char[] charArray) {
        return SegmentFactories.fromArray(charArray);
    }

    /**
     * Creates a heap segment backed by the on-heap region of memory that holds the given
     * short array. The scope of the returned segment is an automatic scope that keeps
     * the given array reachable. The returned segment is always accessible, from any
     * thread. Its {@link #address()} is set to zero.
     *
     * @param shortArray the primitive array backing the heap segment
     * @return a heap memory segment backed by a short array
     */
    static MemorySegment ofArray(short[] shortArray) {
        return SegmentFactories.fromArray(shortArray);
    }

    /**
     * Creates a heap segment backed by the on-heap region of memory that holds the given
     * int array. The scope of the returned segment is an automatic scope that keeps
     * the given array reachable. The returned segment is always accessible, from any
     * thread. Its {@link #address()} is set to zero.
     *
     * @param intArray the primitive array backing the heap segment
     * @return a heap memory segment backed by an int array
     */
    static MemorySegment ofArray(int[] intArray) {
        return SegmentFactories.fromArray(intArray);
    }

    /**
     * Creates a heap segment backed by the on-heap region of memory that holds the given
     * float array. The scope of the returned segment is an automatic scope that keeps
     * the given array reachable. The returned segment is always accessible, from any
     * thread. Its {@link #address()} is set to zero.
     *
     * @param floatArray the primitive array backing the heap segment
     * @return a heap memory segment backed by a float array
     */
    static MemorySegment ofArray(float[] floatArray) {
        return SegmentFactories.fromArray(floatArray);
    }

    /**
     * Creates a heap segment backed by the on-heap region of memory that holds the given
     * long array. The scope of the returned segment is an automatic scope that keeps
     * the given array reachable. The returned segment is always accessible, from any
     * thread. Its {@link #address()} is set to zero.
     *
     * @param longArray the primitive array backing the heap segment
     * @return a heap memory segment backed by a long array
     */
    static MemorySegment ofArray(long[] longArray) {
        return SegmentFactories.fromArray(longArray);
    }

    /**
     * Creates a heap segment backed by the on-heap region of memory that holds the given
     * double array. The scope of the returned segment is an automatic scope that keeps
     * the given array reachable. The returned segment is always accessible, from any
     * thread. Its {@link #address()} is set to zero.
     *
     * @param doubleArray the primitive array backing the heap segment
     * @return a heap memory segment backed by a double array
     */
    static MemorySegment ofArray(double[] doubleArray) {
        return SegmentFactories.fromArray(doubleArray);
    }

    /**
     * A zero-length native segment modelling the {@code NULL} address. Equivalent to
     * {@code MemorySegment.ofAddress(0L)}.
     * <p>
     * The {@linkplain MemorySegment#maxByteAlignment() maximum byte alignment} for
     * the {@code NULL} segment is of 2<sup>62</sup>.
     */
    MemorySegment NULL = MemorySegment.ofAddress(0L);

    /**
     * Creates a zero-length native segment from the given
     * {@linkplain #address() address value}.
     * <p>
     * The returned segment is associated with the global scope and is accessible from
     * any thread.
     * <p>
     * On 32-bit platforms, the given address value will be normalized such that the
     * highest-order ("leftmost") 32 bits of the {@link MemorySegment#address() address}
     * of the returned memory segment are set to zero.
     *
     * @param address the address of the returned native segment
     * @return a zero-length native segment with the given address
     */
    static MemorySegment ofAddress(long address) {
        return SegmentFactories.makeNativeSegmentUnchecked(address, 0);
    }

    /**
     * Performs a bulk copy from source segment to destination segment. More
     * specifically, the bytes at offset {@code srcOffset} through
     * {@code srcOffset + bytes - 1} in the source segment are copied into the
     * destination segment at offset {@code dstOffset} through
     * {@code dstOffset + bytes - 1}.
     * <p>
     * If the source segment overlaps with the destination segment, then the copying is
     * performed as if the bytes at offset {@code srcOffset} through
     * {@code srcOffset + bytes - 1} in the source segment were first copied into a
     * temporary segment with size {@code bytes}, and then the contents of the temporary
     * segment were copied into the destination segment at offset {@code dstOffset}
     * through {@code dstOffset + bytes - 1}.
     * <p>
     * The result of a bulk copy is unspecified if, in the uncommon case, the source
     * segment and the destination segment do not overlap, but refer to overlapping
     * regions of the same backing storage using different addresses. For example, this
     * may occur if the same file is {@linkplain FileChannel#map mapped} to two segments.
     * <p>
     * Calling this method is equivalent to the following code:
     * {@snippet lang=java :
     * MemorySegment.copy(srcSegment, ValueLayout.JAVA_BYTE, srcOffset, dstSegment, ValueLayout.JAVA_BYTE, dstOffset, bytes);
     * }
     * @param srcSegment the source segment
     * @param srcOffset the starting offset, in bytes, of the source segment
     * @param dstSegment the destination segment
     * @param dstOffset the starting offset, in bytes, of the destination segment
     * @param bytes the number of bytes to be copied
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code srcSegment} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code srcSegment.isAccessibleBy(T) == false}
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code dstSegment} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code dstSegment.isAccessibleBy(T) == false}
     * @throws IndexOutOfBoundsException if {@code srcOffset > srcSegment.byteSize() - bytes}
     * @throws IndexOutOfBoundsException if {@code dstOffset > dstSegment.byteSize() - bytes}
     * @throws IndexOutOfBoundsException if either {@code srcOffset},
     *         {@code dstOffset} or {@code bytes} are {@code < 0}
     * @throws IllegalArgumentException if {@code dstSegment} is
     *         {@linkplain #isReadOnly() read-only}
     */
    @ForceInline
    static void copy(MemorySegment srcSegment, long srcOffset,
                     MemorySegment dstSegment, long dstOffset, long bytes) {

        SegmentBulkOperations.copy((AbstractMemorySegmentImpl) srcSegment, srcOffset,
                (AbstractMemorySegmentImpl) dstSegment, dstOffset,
                bytes);
    }

    /**
     * Performs a bulk copy from source segment to destination segment. More
     * specifically, if {@code S} is the byte size of the element layouts, the bytes at
     * offset {@code srcOffset} through {@code srcOffset + (elementCount * S) - 1}
     * in the source segment are copied into the destination segment at offset
     * {@code dstOffset} through {@code dstOffset + (elementCount * S) - 1}.
     * <p>
     * The copy occurs in an element-wise fashion: the bytes in the source segment are
     * interpreted as a sequence of elements whose layout is {@code srcElementLayout},
     * whereas the bytes in the destination segment are interpreted as a sequence of
     * elements whose layout is {@code dstElementLayout}. Both element layouts must have
     * the same size {@code S}. If the byte order of the two provided element layouts
     * differs, the bytes corresponding to each element to be copied are swapped
     * accordingly during the copy operation.
     * <p>
     * If the source segment overlaps with the destination segment, then the copying is
     * performed as if the bytes at offset {@code srcOffset} through
     * {@code srcOffset + (elementCount * S) - 1} in the source segment were first copied
     * into a temporary segment with size {@code bytes}, and then the contents of the
     * temporary segment were copied into the destination segment at offset
     * {@code dstOffset} through {@code dstOffset + (elementCount * S) - 1}.
     * <p>
     * The result of a bulk copy is unspecified if, in the uncommon case, the source
     * segment and the destination segment do not overlap, but refer to overlapping
     * regions of the same backing storage using different addresses. For example,
     * this may occur if the same file is {@linkplain FileChannel#map mapped} to two
     * segments.
     * @param srcSegment the source segment
     * @param srcElementLayout the element layout associated with the source segment
     * @param srcOffset the starting offset, in bytes, of the source segment
     * @param dstSegment the destination segment
     * @param dstElementLayout the element layout associated with the destination segment
     * @param dstOffset the starting offset, in bytes, of the destination segment
     * @param elementCount the number of elements to be copied
     * @throws IllegalArgumentException if the element layouts have different sizes, if
     *         the source (resp. destination) segment/offset are
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the
     *         alignment constraint</a> in the source (resp. destination) element layout
     * @throws IllegalArgumentException if {@code srcElementLayout.byteAlignment() > srcElementLayout.byteSize()}
     * @throws IllegalArgumentException if {@code dstElementLayout.byteAlignment() > dstElementLayout.byteSize()}
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code srcSegment} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code srcSegment.isAccessibleBy(T) == false}
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code dstSegment} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code dstSegment.isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if {@code dstSegment} is {@linkplain #isReadOnly() read-only}
     * @throws IndexOutOfBoundsException if {@code elementCount * srcLayout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code elementCount * dtsLayout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code srcOffset > srcSegment.byteSize() - (elementCount * srcLayout.byteSize())}
     * @throws IndexOutOfBoundsException if {@code dstOffset > dstSegment.byteSize() - (elementCount * dstLayout.byteSize())}
     * @throws IndexOutOfBoundsException if either {@code srcOffset}, {@code dstOffset} or {@code elementCount} are {@code < 0}
     */
    @ForceInline
    static void copy(MemorySegment srcSegment, ValueLayout srcElementLayout, long srcOffset,
                     MemorySegment dstSegment, ValueLayout dstElementLayout, long dstOffset,
                     long elementCount) {
        Objects.requireNonNull(srcSegment);
        Objects.requireNonNull(srcElementLayout);
        Objects.requireNonNull(dstSegment);
        Objects.requireNonNull(dstElementLayout);
        AbstractMemorySegmentImpl.copy(srcSegment, srcElementLayout, srcOffset,
                dstSegment, dstElementLayout, dstOffset,
                elementCount);
    }

    /**
     * Reads a byte from this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be read
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur.
     * @return a byte value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     */
    byte get(ValueLayout.OfByte layout, long offset);

    /**
     * Writes a byte into this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be written
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur.
     * @param value the byte value to be written.
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void set(ValueLayout.OfByte layout, long offset, byte value);

    /**
     * Reads a boolean from this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be read
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur
     * @return a boolean value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     */
    boolean get(ValueLayout.OfBoolean layout, long offset);

    /**
     * Writes a boolean into this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be written
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur
     * @param value the boolean value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated
     *         with this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void set(ValueLayout.OfBoolean layout, long offset, boolean value);

    /**
     * Reads a char from this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be read
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur
     * @return a char value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     */
    char get(ValueLayout.OfChar layout, long offset);

    /**
     * Writes a char into this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be written
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur.
     * @param value the char value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void set(ValueLayout.OfChar layout, long offset, char value);

    /**
     * Reads a short from this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be read
     * @param offset the offset in bytes (relative to this segment address) at which this
     *               access operation will occur
     * @return a short value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     */
    short get(ValueLayout.OfShort layout, long offset);

    /**
     * Writes a short into this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be written
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur.
     * @param value the short value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void set(ValueLayout.OfShort layout, long offset, short value);

    /**
     * Reads an int from this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be read
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur.
     * @return an int value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     */
    int get(ValueLayout.OfInt layout, long offset);

    /**
     * Writes an int into this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be written
     * @param offset the offset in bytes (relative to this segment address) at which this
     *               access operation will occur
     * @param value the int value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void set(ValueLayout.OfInt layout, long offset, int value);

    /**
     * Reads a float from this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be read
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur
     * @return a float value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     */
    float get(ValueLayout.OfFloat layout, long offset);

    /**
     * Writes a float into this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be written
     * @param offset the offset in bytes (relative to this segment address) at which this
     *               access operation will occur
     * @param value the float value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void set(ValueLayout.OfFloat layout, long offset, float value);

    /**
     * Reads a long from this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be read
     * @param offset the offset in bytes (relative to this segment address) at which
     *                this access operation will occur.
     * @return a long value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated
     *         with this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     */
    long get(ValueLayout.OfLong layout, long offset);

    /**
     * Writes a long into this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be written
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur.
     * @param value the long value to be written.
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void set(ValueLayout.OfLong layout, long offset, long value);

    /**
     * Reads a double from this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be read
     * @param offset the offset in bytes (relative to this segment address) at which
     *                this access operation will occur
     * @return a double value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     */
    double get(ValueLayout.OfDouble layout, long offset);

    /**
     * Writes a double into this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be written
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur
     * @param value the double value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void set(ValueLayout.OfDouble layout, long offset, double value);

    /**
     * Reads an address from this segment at the given offset, with the given layout.
     * The read address is wrapped in a native segment, associated with the global scope.
     * Under normal conditions, the size of the returned segment is {@code 0}. However,
     * if the provided address layout has a
     * {@linkplain AddressLayout#targetLayout() target layout} {@code T}, then the size
     * of the returned segment is set to {@code T.byteSize()}.
     *
     * @param layout the layout of the region of memory to be read
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur
     * @return a native segment wrapping an address read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if provided address layout has a
     *         {@linkplain AddressLayout#targetLayout() target layout}
     *         {@code T}, and the address of the returned segment
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in {@code T}
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     */
    MemorySegment get(AddressLayout layout, long offset);

    /**
     * Writes an address into this segment at the given offset, with the given layout.
     *
     * @param layout the layout of the region of memory to be written
     * @param offset the offset in bytes (relative to this segment address) at which
     *               this access operation will occur.
     * @param value the address value to be written.
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IndexOutOfBoundsException if {@code offset > byteSize() - layout.byteSize()}
     *         or {@code offset < 0}
     * @throws IllegalArgumentException if {@code value} is not a
     *         {@linkplain #isNative() native} segment
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void set(AddressLayout layout, long offset, MemorySegment value);

    /**
     * Reads a byte from this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be read
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @return a byte value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     */
    byte getAtIndex(ValueLayout.OfByte layout, long index);

    /**
     * Reads a boolean from this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be read
     * @param index a logical index. The offset in bytes (relative to this
     *             segment address) at which the access operation will occur can be
     *             expressed as {@code (index * layout.byteSize())}.
     * @return a boolean value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     */
    boolean getAtIndex(ValueLayout.OfBoolean layout, long index);

    /**
     * Reads a char from this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be read
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @return a char value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     */
    char getAtIndex(ValueLayout.OfChar layout, long index);

    /**
     * Writes a char into this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be written
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @param value the char value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     * @throws IllegalArgumentException if this segment is {@linkplain #isReadOnly() read-only}
     */
    void setAtIndex(ValueLayout.OfChar layout, long index, char value);

    /**
     * Reads a short from this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be read
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @return a short value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     */
    short getAtIndex(ValueLayout.OfShort layout, long index);

    /**
     * Writes a byte into this segment at the given index, scaled by the given layout size.
     *
     * @param layout the layout of the region of memory to be written
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @param value the short value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     * @throws IllegalArgumentException if this segment is {@linkplain #isReadOnly() read-only}
     */
    void setAtIndex(ValueLayout.OfByte layout, long index, byte value);

    /**
     * Writes a boolean into this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be written
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @param value the short value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     * @throws IllegalArgumentException if this segment is {@linkplain #isReadOnly() read-only}
     */
    void setAtIndex(ValueLayout.OfBoolean layout, long index, boolean value);

    /**
     * Writes a short into this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be written
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @param value the short value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     * @throws IllegalArgumentException if this segment is {@linkplain #isReadOnly() read-only}
     */
    void setAtIndex(ValueLayout.OfShort layout, long index, short value);

    /**
     * Reads an int from this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be read.
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @return an int value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     */
    int getAtIndex(ValueLayout.OfInt layout, long index);

    /**
     * Writes an int into this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be written
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation
     *              will occur can be expressed as {@code (index * layout.byteSize())}.
     * @param value the int value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     * @throws IllegalArgumentException if this segment is {@linkplain #isReadOnly() read-only}
     */
    void setAtIndex(ValueLayout.OfInt layout, long index, int value);

    /**
     * Reads a float from this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be read
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @return a float value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     */
    float getAtIndex(ValueLayout.OfFloat layout, long index);

    /**
     * Writes a float into this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be written
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @param value the float value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     * @throws IllegalArgumentException if this segment is {@linkplain #isReadOnly() read-only}
     */
    void setAtIndex(ValueLayout.OfFloat layout, long index, float value);

    /**
     * Reads a long from this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be read
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @return a long value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     */
    long getAtIndex(ValueLayout.OfLong layout, long index);

    /**
     * Writes a long into this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be written
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @param value the long value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     * @throws IllegalArgumentException if this segment is {@linkplain #isReadOnly() read-only}
     */
    void setAtIndex(ValueLayout.OfLong layout, long index, long value);

    /**
     * Reads a double from this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be read
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @return a double value read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     */
    double getAtIndex(ValueLayout.OfDouble layout, long index);

    /**
     * Writes a double into this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be written
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @param value the double value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     * @throws IllegalArgumentException if this segment is {@linkplain #isReadOnly() read-only}
     */
    void setAtIndex(ValueLayout.OfDouble layout, long index, double value);

    /**
     * Reads an address from this segment at the given at the given index, scaled by the
     * given layout size. The read address is wrapped in a native segment, associated
     * with the global scope. Under normal conditions, the size of the returned segment
     * is {@code 0}. However, if the provided address layout has a
     * {@linkplain AddressLayout#targetLayout() target layout} {@code T}, then the size
     * of the returned segment is set to {@code T.byteSize()}.
     *
     * @param layout the layout of the region of memory to be read
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @return a native segment wrapping an address read from this segment
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout.
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IllegalArgumentException if provided address layout has a
     *         {@linkplain AddressLayout#targetLayout() target layout} {@code T}, and the
     *         address of the returned segment is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in {@code T}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     */
    MemorySegment getAtIndex(AddressLayout layout, long index);

    /**
     * Writes an address into this segment at the given index, scaled by the given
     * layout size.
     *
     * @param layout the layout of the region of memory to be written
     * @param index a logical index. The offset in bytes (relative to this
     *              segment address) at which the access operation will occur can be
     *              expressed as {@code (index * layout.byteSize())}.
     * @param value the address value to be written
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         this segment is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if the access operation is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the provided layout.
     * @throws IllegalArgumentException if {@code layout.byteAlignment() > layout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code index * layout.byteSize() > byteSize() - layout.byteSize()}
     *         or {@code index < 0}
     * @throws IllegalArgumentException if {@code value} is not a {@linkplain #isNative() native} segment
     * @throws IllegalArgumentException if this segment is
     *         {@linkplain #isReadOnly() read-only}
     */
    void setAtIndex(AddressLayout layout, long index, MemorySegment value);

    /**
     * Compares the specified object with this memory segment for equality. Returns
     * {@code true} if and only if the specified object is also a memory segment, and if
     * the two segments refer to the same location, in some region of memory.
     * <p>
     * More specifically, for two segments {@code s1} and {@code s2} to be considered
     * equal, all the following must be true:
     * <ul>
     *     <li>{@code s1.heapBase().equals(s2.heapBase())}, that is, the two segments
     *     must be of the same kind; either both are {@linkplain #isNative() native segments},
     *     backed by off-heap memory, or both are backed by the same on-heap
     *     {@linkplain #heapBase() Java object};
     *     <li>{@code s1.address() == s2.address()}, that is, the address of the two
     *     segments should be the same. This means that the two segments either refer to
     *     the same location in some off-heap region, or they refer to the same offset
     *     inside their associated {@linkplain #heapBase() Java object}.</li>
     * </ul>
     * @apiNote This method does not perform a structural comparison of the contents of
     *          the two memory segments. Clients can compare memory segments structurally
     *          by using the {@link #mismatch(MemorySegment)} method instead. Note that
     *          this method does <em>not</em> compare the temporal and spatial bounds of
     *          two segments. As such, it is suitable to check whether two segments have
     *          the same address.
     *
     * @param that the object to be compared for equality with this memory segment
     * @return {@code true} if the specified object is equal to this memory segment
     * @see #mismatch(MemorySegment)
     */
    @Override
    boolean equals(Object that);

    /**
     * {@return the hash code value for this memory segment}
     */
    @Override
    int hashCode();


    /**
     * Copies a number of elements from a source memory segment to a destination array.
     * The elements, whose size and alignment constraints are specified by the given
     * layout, are read from the source segment, starting at the given offset
     * (expressed in bytes), and are copied into the destination array, at the
     * given index.
     * <p>
     * Supported array types are :
     * {@code byte[]}, {@code char[]}, {@code short[]},
     * {@code int[]}, {@code float[]}, {@code long[]} and {@code double[]}.
     *
     * @param srcSegment the source segment
     * @param srcLayout the source element layout. If the byte order associated with the
     *                 layout is different from the
     *                 {@linkplain ByteOrder#nativeOrder native order}, a byte swap
     *                  operation will be performed on each array element
     * @param srcOffset the starting offset, in bytes, of the source segment
     * @param dstArray the destination array
     * @param dstIndex the starting index of the destination array
     * @param elementCount the number of array elements to be copied
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code srcSegment} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code srcSegment.isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if {@code dstArray} is not an array, or if it is
     *         an array but whose type is not supported
     * @throws IllegalArgumentException if the destination array component type does not
     *         match {@code srcLayout.carrier()}
     * @throws IllegalArgumentException if {@code offset} is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the source element layout
     * @throws IllegalArgumentException if {@code srcLayout.byteAlignment() > srcLayout.byteSize()}
     * @throws IndexOutOfBoundsException if {@code elementCount * srcLayout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code srcOffset > srcSegment.byteSize() - (elementCount * srcLayout.byteSize())}
     * @throws IndexOutOfBoundsException if {@code dstIndex > dstArray.length - elementCount}
     * @throws IndexOutOfBoundsException if either {@code srcOffset}, {@code dstIndex} or {@code elementCount} are {@code < 0}
     */
    @ForceInline
    static void copy(MemorySegment srcSegment, ValueLayout srcLayout, long srcOffset,
                     Object dstArray, int dstIndex,
                     int elementCount) {
        Objects.requireNonNull(srcSegment);
        Objects.requireNonNull(dstArray);
        Objects.requireNonNull(srcLayout);

        AbstractMemorySegmentImpl.copy(srcSegment, srcLayout, srcOffset,
                dstArray, dstIndex,
                elementCount);
    }

    /**
     * Copies a number of elements from a source array to a destination memory segment.
     * <p>
     * The elements, whose size and alignment constraints are specified by the given
     * layout, are read from the source array, starting at the given index, and are
     * copied into the destination segment, at the given offset (expressed in bytes).
     * <p>
     * Supported array types are
     * {@code byte[]}, {@code char[]}, {@code short[]},
     * {@code int[]}, {@code float[]}, {@code long[]} and {@code double[]}.
     *
     * @param srcArray the source array
     * @param srcIndex the starting index of the source array
     * @param dstSegment the destination segment
     * @param dstLayout the destination element layout. If the byte order associated
     *                  with the layout is different from the
     *                  {@linkplain ByteOrder#nativeOrder native order}, a byte swap
     *                  operation will be performed on each array element.
     * @param dstOffset the starting offset, in bytes, of the destination segment
     * @param elementCount the number of array elements to be copied
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code dstSegment} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code dstSegment.isAccessibleBy(T) == false}
     * @throws IllegalArgumentException if {@code srcArray} is not an array, or if it is
     *         an array but whose type is not supported
     * @throws IllegalArgumentException if the source array component type does not
     *         match {@code srcLayout.carrier()}
     * @throws IllegalArgumentException if {@code offset} is
     *         <a href="MemorySegment.html#segment-alignment">incompatible with the alignment constraint</a>
     *         in the source element layout
     * @throws IllegalArgumentException if {@code dstLayout.byteAlignment() > dstLayout.byteSize()}
     * @throws IllegalArgumentException if {@code dstSegment} is {@linkplain #isReadOnly() read-only}
     * @throws IndexOutOfBoundsException if {@code elementCount * dstLayout.byteSize()} overflows
     * @throws IndexOutOfBoundsException if {@code dstOffset > dstSegment.byteSize() - (elementCount * dstLayout.byteSize())}
     * @throws IndexOutOfBoundsException if {@code srcIndex > srcArray.length - elementCount}
     * @throws IndexOutOfBoundsException if either {@code srcIndex}, {@code dstOffset} or {@code elementCount} are {@code < 0}
     */
    @ForceInline
    static void copy(Object srcArray, int srcIndex,
                     MemorySegment dstSegment, ValueLayout dstLayout, long dstOffset,
                     int elementCount) {
        Objects.requireNonNull(srcArray);
        Objects.requireNonNull(dstSegment);
        Objects.requireNonNull(dstLayout);

        AbstractMemorySegmentImpl.copy(srcArray, srcIndex,
                dstSegment, dstLayout, dstOffset,
                elementCount);
    }

    /**
     * Finds and returns the relative offset, in bytes, of the first mismatch between the
     * source and the destination segments. More specifically, the bytes at offset
     * {@code srcFromOffset} through {@code srcToOffset - 1} in the source segment are
     * compared against the bytes at offset {@code dstFromOffset} through {@code dstToOffset - 1}
     * in the destination segment.
     * <p>
     * If the two segments, over the specified ranges, share a common prefix then the
     * returned offset is the length of the common prefix, and it follows that there is a
     * mismatch between the two segments at that relative offset within the respective
     * segments. If one segment is a proper prefix of the other, over the specified
     * ranges, then the returned offset is the smallest range, and it follows that the
     * relative offset is only valid for the segment with the larger range. Otherwise,
     * there is no mismatch and {@code -1} is returned.
     *
     * @param srcSegment the source segment.
     * @param srcFromOffset the offset (inclusive) of the first byte in the
     *                      source segment to be tested
     * @param srcToOffset the offset (exclusive) of the last byte in the
     *                    source segment to be tested
     * @param dstSegment the destination segment
     * @param dstFromOffset the offset (inclusive) of the first byte in the
     *                      destination segment to be tested
     * @param dstToOffset the offset (exclusive) of the last byte in the
     *                    destination segment to be tested
     * @return the relative offset, in bytes, of the first mismatch between the
     *         source and destination segments, otherwise -1 if no mismatch
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code srcSegment} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code srcSegment.isAccessibleBy(T) == false}
     * @throws IllegalStateException if the {@linkplain #scope() scope} associated with
     *         {@code dstSegment} is not {@linkplain Scope#isAlive() alive}
     * @throws WrongThreadException if this method is called from a thread {@code T},
     *         such that {@code dstSegment.isAccessibleBy(T) == false}
     * @throws IndexOutOfBoundsException if {@code srcFromOffset < 0},
     *         {@code srcToOffset < srcFromOffset} or
     *         {@code srcToOffset > srcSegment.byteSize()}
     * @throws IndexOutOfBoundsException if {@code dstFromOffset < 0},
     *         {@code dstToOffset < dstFromOffset} or
     *         {@code dstToOffset > dstSegment.byteSize()}
     *
     * @see MemorySegment#mismatch(MemorySegment)
     * @see Arrays#mismatch(Object[], int, int, Object[], int, int)
     */
    static long mismatch(MemorySegment srcSegment, long srcFromOffset, long srcToOffset,
                         MemorySegment dstSegment, long dstFromOffset, long dstToOffset) {
        return SegmentBulkOperations.mismatch(
                (AbstractMemorySegmentImpl)Objects.requireNonNull(srcSegment), srcFromOffset, srcToOffset,
                (AbstractMemorySegmentImpl)Objects.requireNonNull(dstSegment), dstFromOffset, dstToOffset);
    }

    /**
     * A scope models the <em>lifetime</em> of all the memory segments associated with it.
     * <p>
     * That is, a memory segment cannot be accessed if its associated scope is not
     * {@linkplain #isAlive() alive}. Scope instances can be compared for equality.
     * That is, two scopes are considered {@linkplain #equals(Object) equal} if they
     * denote the same lifetime.
     * <p>
     * The lifetime of a memory segment can be either <em>unbounded</em> or
     * <em>bounded</em>. An unbounded lifetime is modeled with the <em>global scope</em>.
     * The global scope is always {@link #isAlive() alive}. As such, a segment associated
     * with the global scope features trivial temporal bounds and is always accessible.
     * Segments associated with the global scope are:
     * <ul>
     *     <li>Segments obtained from the {@linkplain Arena#global() global arena};</li>
     *     <li>Segments obtained from a raw address, using the
     *         {@link MemorySegment#ofAddress(long)} factory; and</li>
     *     <li>{@link MemorySegment##wrapping-addresses Zero-length memory segments}.</li>
     * </ul>
     * <p>
     * Conversely, a bounded lifetime is modeled with a segment scope that can be
     * invalidated, either {@link Arena#close() explicitly}, or automatically, by the
     * garbage collector. A segment scope that is invalidated automatically is an
     * <em>automatic scope</em>. An automatic scope is always {@link #isAlive() alive}
     * as long as it is {@linkplain java.lang.ref##reachability reachable}.
     * Segments associated with an automatic scope are:
     * <ul>
     *     <li>Segments obtained from an {@linkplain Arena#ofAuto() automatic arena};</li>
     *     <li>Segments obtained from a Java array, e.g. using the
     *         {@link MemorySegment#ofArray(int[])} factory;</li>
     *     <li>Segments obtained from a buffer, using the
     *         {@link MemorySegment#ofBuffer(Buffer)} factory; and</li>
     *     <li>Segments obtained from {@linkplain SymbolLookup#loaderLookup() loader lookup}.</li>
     * </ul>
     * If two memory segments are obtained from the same
     * {@linkplain #ofBuffer(Buffer) buffer} or {@linkplain #ofArray(int[]) array}, the
     * automatic scopes associated with said segments are considered
     * {@linkplain #equals(Object) equal}, as the two segments have the same lifetime:
     * {@snippet lang=java :
     * byte[] arr = new byte[10];
     * MemorySegment segment1 = MemorySegment.ofArray(arr);
     * MemorySegment segment2 = MemorySegment.ofArray(arr);
     * assert segment1.scope().equals(segment2.scope());
     * }
     */
    sealed interface Scope permits MemorySessionImpl {
        /**
         * {@return {@code true}, if the regions of memory backing the memory segments
         * associated with this scope are still valid}
         */
        boolean isAlive();

        /**
         * {@return {@code true}, if the provided object is also a scope, which models
         * the same lifetime as that modeled by this scope}. In that case, it is always
         * the case that {@code this.isAlive() == ((Scope)that).isAlive()}.
         *
         * @param that the object to be tested
         */
        @Override
        boolean equals(Object that);

        /**
         * {@return the hash code of this scope object}
         *
         * @implSpec Implementations of this method obey the general contract of
         *           {@link Object#hashCode}.
         *
         * @see #equals(Object)
         */
        @Override
        int hashCode();
    }
}