view src/cpu/zero/vm/copy_zero.hpp @ 3249:e1162778c1c8

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer. Reviewed-by: kvn, iveresov, never, tonyp, dholmes
author johnc
date Thu, 07 Apr 2011 09:53:20 -0700
parents f95d63e2154a
children
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/*
 * 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