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/*
* Copyright (c) 2003, 2022, 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.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_UTILITIES_COPY_HPP
#define SHARE_UTILITIES_COPY_HPP
#include "oops/oopsHierarchy.hpp"
#include "runtime/atomic.hpp"
#include "runtime/globals.hpp"
#include "utilities/align.hpp"
#include "utilities/bytes.hpp"
#include "utilities/debug.hpp"
#include "utilities/macros.hpp"
// Assembly code for platforms that need it.
extern "C" {
void _Copy_conjoint_words(const HeapWord* from, HeapWord* to, size_t count);
void _Copy_disjoint_words(const HeapWord* from, HeapWord* to, size_t count);
void _Copy_conjoint_jshorts_atomic(const jshort* from, jshort* to, size_t count);
void _Copy_conjoint_jints_atomic (const jint* from, jint* to, size_t count);
void _Copy_conjoint_jlongs_atomic (const jlong* from, jlong* to, size_t count);
void _Copy_conjoint_oops_atomic (const oop* from, oop* to, size_t count);
void _Copy_arrayof_conjoint_bytes (const HeapWord* from, HeapWord* to, size_t count);
void _Copy_arrayof_conjoint_jshorts(const HeapWord* from, HeapWord* to, size_t count);
void _Copy_arrayof_conjoint_jints (const HeapWord* from, HeapWord* to, size_t count);
void _Copy_arrayof_conjoint_jlongs (const HeapWord* from, HeapWord* to, size_t count);
}
class Copy : AllStatic {
public:
// Block copy methods have four attributes. We don't define all possibilities.
// alignment: aligned to BytesPerLong
// arrayof: arraycopy operation with both operands aligned on the same
// boundary as the first element of an array of the copy unit.
// This is currently a HeapWord boundary on all platforms, except
// for long and double arrays, which are aligned on an 8-byte
// boundary on all platforms.
// arraycopy operations are implicitly atomic on each array element.
// overlap: disjoint or conjoint.
// copy unit: bytes or words (i.e., HeapWords) or oops (i.e., pointers).
// atomicity: atomic or non-atomic on the copy unit.
//
// Names are constructed thusly:
//
// [ 'aligned_' | 'arrayof_' ]
// ('conjoint_' | 'disjoint_')
// ('words' | 'bytes' | 'jshorts' | 'jints' | 'jlongs' | 'oops')
// [ '_atomic' ]
//
// Except in the arrayof case, whatever the alignment is, we assume we can copy
// whole alignment units. E.g., if BytesPerLong is 2x word alignment, an odd
// count may copy an extra word. In the arrayof case, we are allowed to copy
// only the number of copy units specified.
//
// All callees check count for 0.
//
// HeapWords
// Word-aligned words, conjoint, not atomic on each word
static void conjoint_words(const HeapWord* from, HeapWord* to, size_t count) {
assert_params_ok(from, to, HeapWordSize);
pd_conjoint_words(from, to, count);
}
// Word-aligned words, disjoint, not atomic on each word
static void disjoint_words(const HeapWord* from, HeapWord* to, size_t count) {
assert_params_ok(from, to, HeapWordSize);
assert_disjoint(from, to, count);
pd_disjoint_words(from, to, count);
}
// Word-aligned words, disjoint, atomic on each word
static void disjoint_words_atomic(const HeapWord* from, HeapWord* to, size_t count) {
assert_params_ok(from, to, HeapWordSize);
assert_disjoint(from, to, count);
pd_disjoint_words_atomic(from, to, count);
}
// Object-aligned words, conjoint, not atomic on each word
static void aligned_conjoint_words(const HeapWord* from, HeapWord* to, size_t count) {
assert_params_aligned(from, to);
pd_aligned_conjoint_words(from, to, count);
}
// Object-aligned words, disjoint, not atomic on each word
static void aligned_disjoint_words(const HeapWord* from, HeapWord* to, size_t count) {
assert_params_aligned(from, to);
assert_disjoint(from, to, count);
pd_aligned_disjoint_words(from, to, count);
}
// bytes, jshorts, jints, jlongs, oops
// bytes, conjoint, not atomic on each byte (not that it matters)
static void conjoint_jbytes(const void* from, void* to, size_t count) {
pd_conjoint_bytes(from, to, count);
}
// bytes, conjoint, atomic on each byte (not that it matters)
static void conjoint_jbytes_atomic(const void* from, void* to, size_t count) {
pd_conjoint_bytes(from, to, count);
}
// jshorts, conjoint, atomic on each jshort
static void conjoint_jshorts_atomic(const jshort* from, jshort* to, size_t count) {
assert_params_ok(from, to, BytesPerShort);
pd_conjoint_jshorts_atomic(from, to, count);
}
// jints, conjoint, atomic on each jint
static void conjoint_jints_atomic(const jint* from, jint* to, size_t count) {
assert_params_ok(from, to, BytesPerInt);
pd_conjoint_jints_atomic(from, to, count);
}
// jlongs, conjoint, atomic on each jlong
static void conjoint_jlongs_atomic(const jlong* from, jlong* to, size_t count) {
assert_params_ok(from, to, BytesPerLong);
pd_conjoint_jlongs_atomic(from, to, count);
}
// oops, conjoint, atomic on each oop
static void conjoint_oops_atomic(const oop* from, oop* to, size_t count) {
assert_params_ok(from, to, BytesPerHeapOop);
pd_conjoint_oops_atomic(from, to, count);
}
// overloaded for UseCompressedOops
static void conjoint_oops_atomic(const narrowOop* from, narrowOop* to, size_t count) {
assert(sizeof(narrowOop) == sizeof(jint), "this cast is wrong");
assert_params_ok(from, to, BytesPerInt);
pd_conjoint_jints_atomic((const jint*)from, (jint*)to, count);
}
// Copy a span of memory. If the span is an integral number of aligned
// longs, words, or ints, copy those units atomically.
// The largest atomic transfer unit is 8 bytes, or the largest power
// of two which divides all of from, to, and size, whichever is smaller.
static void conjoint_memory_atomic(const void* from, void* to, size_t size);
// bytes, conjoint array, atomic on each byte (not that it matters)
static void arrayof_conjoint_jbytes(const HeapWord* from, HeapWord* to, size_t count) {
pd_arrayof_conjoint_bytes(from, to, count);
}
// jshorts, conjoint array, atomic on each jshort
static void arrayof_conjoint_jshorts(const HeapWord* from, HeapWord* to, size_t count) {
assert_params_ok(from, to, BytesPerShort);
pd_arrayof_conjoint_jshorts(from, to, count);
}
// jints, conjoint array, atomic on each jint
static void arrayof_conjoint_jints(const HeapWord* from, HeapWord* to, size_t count) {
assert_params_ok(from, to, BytesPerInt);
pd_arrayof_conjoint_jints(from, to, count);
}
// jlongs, conjoint array, atomic on each jlong
static void arrayof_conjoint_jlongs(const HeapWord* from, HeapWord* to, size_t count) {
assert_params_ok(from, to, BytesPerLong);
pd_arrayof_conjoint_jlongs(from, to, count);
}
// oops, conjoint array, atomic on each oop
static void arrayof_conjoint_oops(const HeapWord* from, HeapWord* to, size_t count) {
assert_params_ok(from, to, BytesPerHeapOop);
pd_arrayof_conjoint_oops(from, to, count);
}
// Known overlap methods
// Copy word-aligned words from higher to lower addresses, not atomic on each word
inline static void conjoint_words_to_lower(const HeapWord* from, HeapWord* to, size_t byte_count) {
// byte_count is in bytes to check its alignment
assert_params_ok(from, to, HeapWordSize);
assert_byte_count_ok(byte_count, HeapWordSize);
size_t count = align_up(byte_count, HeapWordSize) >> LogHeapWordSize;
assert(to <= from || from + count <= to, "do not overwrite source data");
while (count-- > 0) {
*to++ = *from++;
}
}
// Copy word-aligned words from lower to higher addresses, not atomic on each word
inline static void conjoint_words_to_higher(const HeapWord* from, HeapWord* to, size_t byte_count) {
// byte_count is in bytes to check its alignment
assert_params_ok(from, to, HeapWordSize);
assert_byte_count_ok(byte_count, HeapWordSize);
size_t count = align_up(byte_count, HeapWordSize) >> LogHeapWordSize;
assert(from <= to || to + count <= from, "do not overwrite source data");
from += count - 1;
to += count - 1;
while (count-- > 0) {
*to-- = *from--;
}
}
/**
* Copy elements
*
* @param src address of source
* @param dst address of destination
* @param byte_count number of bytes to copy
* @param elem_size size of the elements to copy-swap
*/
static void conjoint_copy(const void* src, void* dst, size_t byte_count, size_t elem_size);
/**
* Copy and *unconditionally* byte swap elements
*
* @param src address of source
* @param dst address of destination
* @param byte_count number of bytes to copy
* @param elem_size size of the elements to copy-swap
*/
static void conjoint_swap(const void* src, void* dst, size_t byte_count, size_t elem_size);
/**
* Copy and byte swap elements from the specified endian to the native (cpu) endian if needed (if they differ)
*
* @param src address of source
* @param dst address of destination
* @param byte_count number of bytes to copy
* @param elem_size size of the elements to copy-swap
*/
template <Endian::Order endian>
static void conjoint_swap_if_needed(const void* src, void* dst, size_t byte_count, size_t elem_size) {
if (Endian::NATIVE != endian) {
conjoint_swap(src, dst, byte_count, elem_size);
} else {
conjoint_copy(src, dst, byte_count, elem_size);
}
}
// Fill methods
// Fill word-aligned words, not atomic on each word
// set_words
static void fill_to_words(HeapWord* to, size_t count, juint value = 0) {
assert_params_ok(to, HeapWordSize);
pd_fill_to_words(to, count, value);
}
static void fill_to_aligned_words(HeapWord* to, size_t count, juint value = 0) {
assert_params_aligned(to);
pd_fill_to_aligned_words(to, count, value);
}
// Fill bytes
static void fill_to_bytes(void* to, size_t count, jubyte value = 0) {
pd_fill_to_bytes(to, count, value);
}
// Fill a span of memory. If the span is an integral number of aligned
// longs, words, or ints, store to those units atomically.
// The largest atomic transfer unit is 8 bytes, or the largest power
// of two which divides both to and size, whichever is smaller.
static void fill_to_memory_atomic(void* to, size_t size, jubyte value = 0);
// Zero-fill methods
// Zero word-aligned words, not atomic on each word
static void zero_to_words(HeapWord* to, size_t count) {
assert_params_ok(to, HeapWordSize);
pd_zero_to_words(to, count);
}
// Zero bytes
static void zero_to_bytes(void* to, size_t count) {
pd_zero_to_bytes(to, count);
}
protected:
inline static void shared_disjoint_words_atomic(const HeapWord* from,
HeapWord* to, size_t count) {
switch (count) {
case 8: Atomic::store(&to[7], Atomic::load(&from[7]));
case 7: Atomic::store(&to[6], Atomic::load(&from[6]));
case 6: Atomic::store(&to[5], Atomic::load(&from[5]));
case 5: Atomic::store(&to[4], Atomic::load(&from[4]));
case 4: Atomic::store(&to[3], Atomic::load(&from[3]));
case 3: Atomic::store(&to[2], Atomic::load(&from[2]));
case 2: Atomic::store(&to[1], Atomic::load(&from[1]));
case 1: Atomic::store(&to[0], Atomic::load(&from[0]));
case 0: break;
default:
while (count-- > 0) {
Atomic::store(to++, Atomic::load(from++));
}
break;
}
}
private:
static bool params_disjoint(const HeapWord* from, HeapWord* to, size_t count) {
if (from < to) {
return pointer_delta(to, from) >= count;
}
return pointer_delta(from, to) >= count;
}
// These methods raise a fatal if they detect a problem.
static void assert_disjoint(const HeapWord* from, HeapWord* to, size_t count) {
assert(params_disjoint(from, to, count), "source and dest overlap");
}
static void assert_params_ok(const void* from, void* to, intptr_t alignment) {
assert(is_aligned(from, alignment), "must be aligned: " PTR_FORMAT, p2i(from));
assert(is_aligned(to, alignment), "must be aligned: " PTR_FORMAT, p2i(to));
}
static void assert_params_ok(HeapWord* to, intptr_t alignment) {
assert(is_aligned(to, alignment), "must be aligned: " PTR_FORMAT, p2i(to));
}
static void assert_params_aligned(const HeapWord* from, HeapWord* to) {
assert(is_aligned(from, BytesPerLong), "must be aligned: " PTR_FORMAT, p2i(from));
assert(is_aligned(to, BytesPerLong), "must be aligned: " PTR_FORMAT, p2i(to));
}
static void assert_params_aligned(HeapWord* to) {
assert(is_aligned(to, BytesPerLong), "must be aligned: " PTR_FORMAT, p2i(to));
}
static void assert_byte_count_ok(size_t byte_count, size_t unit_size) {
assert(is_aligned(byte_count, unit_size), "byte count must be aligned");
}
// Platform dependent implementations of the above methods.
#include CPU_HEADER(copy)
};
#endif // SHARE_UTILITIES_COPY_HPP
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