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Java example source code file (copy_zero.hpp)

This example Java source code file (copy_zero.hpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytesperoop, cpu_zero_vm_copy_zero_hpp, heapword, heapwordsize

The copy_zero.hpp Java example source code

/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2007 Red Hat, Inc.
 * 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 CPU_ZERO_VM_COPY_ZERO_HPP
#define CPU_ZERO_VM_COPY_ZERO_HPP

// Inline functions for memory copy and fill.

static void pd_conjoint_words(HeapWord* from, HeapWord* to, size_t count) {
  memmove(to, from, count * HeapWordSize);
}

static void pd_disjoint_words(HeapWord* from, HeapWord* to, size_t count) {
  switch (count) {
  case 8:  to[7] = from[7];
  case 7:  to[6] = from[6];
  case 6:  to[5] = from[5];
  case 5:  to[4] = from[4];
  case 4:  to[3] = from[3];
  case 3:  to[2] = from[2];
  case 2:  to[1] = from[1];
  case 1:  to[0] = from[0];
  case 0:  break;
  default:
    memcpy(to, from, count * HeapWordSize);
    break;
  }
}

static void pd_disjoint_words_atomic(HeapWord* from,
                                     HeapWord* to,
                                     size_t count) {
  switch (count) {
  case 8:  to[7] = from[7];
  case 7:  to[6] = from[6];
  case 6:  to[5] = from[5];
  case 5:  to[4] = from[4];
  case 4:  to[3] = from[3];
  case 3:  to[2] = from[2];
  case 2:  to[1] = from[1];
  case 1:  to[0] = from[0];
  case 0:  break;
  default:
    while (count-- > 0) {
      *to++ = *from++;
    }
    break;
  }
}

static void pd_aligned_conjoint_words(HeapWord* from,
                                      HeapWord* to,
                                      size_t count) {
  memmove(to, from, count * HeapWordSize);
}

static void pd_aligned_disjoint_words(HeapWord* from,
                                      HeapWord* to,
                                      size_t count) {
  pd_disjoint_words(from, to, count);
}

static void pd_conjoint_bytes(void* from, void* to, size_t count) {
  memmove(to, from, count);
}

static void pd_conjoint_bytes_atomic(void* from, void* to, size_t count) {
  memmove(to, from, count);
}

static void pd_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
  _Copy_conjoint_jshorts_atomic(from, to, count);
}

static void pd_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
  _Copy_conjoint_jints_atomic(from, to, count);
}

static void pd_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
  _Copy_conjoint_jlongs_atomic(from, to, count);
}

static void pd_conjoint_oops_atomic(oop* from, oop* to, size_t count) {
#ifdef _LP64
  assert(BytesPerLong == BytesPerOop, "jlongs and oops must be the same size");
  _Copy_conjoint_jlongs_atomic((jlong*)from, (jlong*)to, count);
#else
  assert(BytesPerInt == BytesPerOop, "jints and oops must be the same size");
  _Copy_conjoint_jints_atomic((jint*)from, (jint*)to, count);
#endif // _LP64
}

static void pd_arrayof_conjoint_bytes(HeapWord* from,
                                      HeapWord* to,
                                      size_t    count) {
  _Copy_arrayof_conjoint_bytes(from, to, count);
}

static void pd_arrayof_conjoint_jshorts(HeapWord* from,
                                        HeapWord* to,
                                        size_t    count) {
  _Copy_arrayof_conjoint_jshorts(from, to, count);
}

static void pd_arrayof_conjoint_jints(HeapWord* from,
                                      HeapWord* to,
                                      size_t    count) {
  _Copy_arrayof_conjoint_jints(from, to, count);
}

static void pd_arrayof_conjoint_jlongs(HeapWord* from,
                                       HeapWord* to,
                                       size_t    count) {
  _Copy_arrayof_conjoint_jlongs(from, to, count);
}

static void pd_arrayof_conjoint_oops(HeapWord* from,
                                     HeapWord* to,
                                     size_t    count) {
#ifdef _LP64
  assert(BytesPerLong == BytesPerOop, "jlongs and oops must be the same size");
  _Copy_arrayof_conjoint_jlongs(from, to, count);
#else
  assert(BytesPerInt == BytesPerOop, "jints and oops must be the same size");
  _Copy_arrayof_conjoint_jints(from, to, count);
#endif // _LP64
}

static void pd_fill_to_words(HeapWord* tohw, size_t count, juint value) {
#ifdef _LP64
  julong* to = (julong*) tohw;
  julong  v  = ((julong) value << 32) | value;
#else
  juint* to = (juint*) tohw;
  juint  v  = value;
#endif // _LP64

  while (count-- > 0) {
    *to++ = v;
  }
}

static void pd_fill_to_aligned_words(HeapWord* tohw,
                                     size_t    count,
                                     juint     value) {
  pd_fill_to_words(tohw, count, value);
}

static void pd_fill_to_bytes(void* to, size_t count, jubyte value) {
  memset(to, value, count);
}

static void pd_zero_to_words(HeapWord* tohw, size_t count) {
  pd_fill_to_words(tohw, count, 0);
}

static void pd_zero_to_bytes(void* to, size_t count) {
  memset(to, 0, count);
}

#endif // CPU_ZERO_VM_COPY_ZERO_HPP

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