hotspot/src/share/vm/memory/space.inline.hpp
author ysr
Wed, 07 Sep 2011 13:55:42 -0700
changeset 10526 3e92f211533f
parent 7397 5b173b4ca846
child 12597 904566185bdf
permissions -rw-r--r--
4965777: GC changes to support use of discovered field for pending references Summary: If and when the reference handler thread is able to use the discovered field to link reference objects in its pending list, so will GC. In that case, GC will scan through this field once a reference object has been placed on the pending list, but not scan that field before that stage, as the field is used by the concurrent GC thread to link discovered objects. When ReferenceHandleR thread does not use the discovered field for the purpose of linking the elements in the pending list, as would be the case in older JDKs, the JVM will fall back to the old behaviour of using the next field for that purpose. Reviewed-by: jcoomes, mchung, stefank
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
     1
/*
7397
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
     2
 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
     3
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
489c9b5090e2 Initial load
duke
parents:
diff changeset
     4
 *
489c9b5090e2 Initial load
duke
parents:
diff changeset
     5
 * This code is free software; you can redistribute it and/or modify it
489c9b5090e2 Initial load
duke
parents:
diff changeset
     6
 * under the terms of the GNU General Public License version 2 only, as
489c9b5090e2 Initial load
duke
parents:
diff changeset
     7
 * published by the Free Software Foundation.
489c9b5090e2 Initial load
duke
parents:
diff changeset
     8
 *
489c9b5090e2 Initial load
duke
parents:
diff changeset
     9
 * This code is distributed in the hope that it will be useful, but WITHOUT
489c9b5090e2 Initial load
duke
parents:
diff changeset
    10
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
489c9b5090e2 Initial load
duke
parents:
diff changeset
    11
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
489c9b5090e2 Initial load
duke
parents:
diff changeset
    12
 * version 2 for more details (a copy is included in the LICENSE file that
489c9b5090e2 Initial load
duke
parents:
diff changeset
    13
 * accompanied this code).
489c9b5090e2 Initial load
duke
parents:
diff changeset
    14
 *
489c9b5090e2 Initial load
duke
parents:
diff changeset
    15
 * You should have received a copy of the GNU General Public License version
489c9b5090e2 Initial load
duke
parents:
diff changeset
    16
 * 2 along with this work; if not, write to the Free Software Foundation,
489c9b5090e2 Initial load
duke
parents:
diff changeset
    17
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
489c9b5090e2 Initial load
duke
parents:
diff changeset
    18
 *
5547
f4b087cbb361 6941466: Oracle rebranding changes for Hotspot repositories
trims
parents: 1374
diff changeset
    19
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
f4b087cbb361 6941466: Oracle rebranding changes for Hotspot repositories
trims
parents: 1374
diff changeset
    20
 * or visit www.oracle.com if you need additional information or have any
f4b087cbb361 6941466: Oracle rebranding changes for Hotspot repositories
trims
parents: 1374
diff changeset
    21
 * questions.
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
    22
 *
489c9b5090e2 Initial load
duke
parents:
diff changeset
    23
 */
489c9b5090e2 Initial load
duke
parents:
diff changeset
    24
7397
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    25
#ifndef SHARE_VM_MEMORY_SPACE_INLINE_HPP
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    26
#define SHARE_VM_MEMORY_SPACE_INLINE_HPP
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    27
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    28
#include "gc_interface/collectedHeap.hpp"
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    29
#include "memory/space.hpp"
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    30
#include "memory/universe.hpp"
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    31
#include "runtime/safepoint.hpp"
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    32
1374
4c24294029a9 6711316: Open source the Garbage-First garbage collector
ysr
parents: 1
diff changeset
    33
inline HeapWord* Space::block_start(const void* p) {
4c24294029a9 6711316: Open source the Garbage-First garbage collector
ysr
parents: 1
diff changeset
    34
  return block_start_const(p);
4c24294029a9 6711316: Open source the Garbage-First garbage collector
ysr
parents: 1
diff changeset
    35
}
4c24294029a9 6711316: Open source the Garbage-First garbage collector
ysr
parents: 1
diff changeset
    36
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
    37
inline HeapWord* OffsetTableContigSpace::allocate(size_t size) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
    38
  HeapWord* res = ContiguousSpace::allocate(size);
489c9b5090e2 Initial load
duke
parents:
diff changeset
    39
  if (res != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
    40
    _offsets.alloc_block(res, size);
489c9b5090e2 Initial load
duke
parents:
diff changeset
    41
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
    42
  return res;
489c9b5090e2 Initial load
duke
parents:
diff changeset
    43
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
    44
489c9b5090e2 Initial load
duke
parents:
diff changeset
    45
// Because of the requirement of keeping "_offsets" up to date with the
489c9b5090e2 Initial load
duke
parents:
diff changeset
    46
// allocations, we sequentialize these with a lock.  Therefore, best if
489c9b5090e2 Initial load
duke
parents:
diff changeset
    47
// this is used for larger LAB allocations only.
489c9b5090e2 Initial load
duke
parents:
diff changeset
    48
inline HeapWord* OffsetTableContigSpace::par_allocate(size_t size) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
    49
  MutexLocker x(&_par_alloc_lock);
489c9b5090e2 Initial load
duke
parents:
diff changeset
    50
  // This ought to be just "allocate", because of the lock above, but that
489c9b5090e2 Initial load
duke
parents:
diff changeset
    51
  // ContiguousSpace::allocate asserts that either the allocating thread
489c9b5090e2 Initial load
duke
parents:
diff changeset
    52
  // holds the heap lock or it is the VM thread and we're at a safepoint.
489c9b5090e2 Initial load
duke
parents:
diff changeset
    53
  // The best I (dld) could figure was to put a field in ContiguousSpace
489c9b5090e2 Initial load
duke
parents:
diff changeset
    54
  // meaning "locking at safepoint taken care of", and set/reset that
489c9b5090e2 Initial load
duke
parents:
diff changeset
    55
  // here.  But this will do for now, especially in light of the comment
489c9b5090e2 Initial load
duke
parents:
diff changeset
    56
  // above.  Perhaps in the future some lock-free manner of keeping the
489c9b5090e2 Initial load
duke
parents:
diff changeset
    57
  // coordination.
489c9b5090e2 Initial load
duke
parents:
diff changeset
    58
  HeapWord* res = ContiguousSpace::par_allocate(size);
489c9b5090e2 Initial load
duke
parents:
diff changeset
    59
  if (res != NULL) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
    60
    _offsets.alloc_block(res, size);
489c9b5090e2 Initial load
duke
parents:
diff changeset
    61
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
    62
  return res;
489c9b5090e2 Initial load
duke
parents:
diff changeset
    63
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
    64
1374
4c24294029a9 6711316: Open source the Garbage-First garbage collector
ysr
parents: 1
diff changeset
    65
inline HeapWord*
4c24294029a9 6711316: Open source the Garbage-First garbage collector
ysr
parents: 1
diff changeset
    66
OffsetTableContigSpace::block_start_const(const void* p) const {
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
    67
  return _offsets.block_start(p);
489c9b5090e2 Initial load
duke
parents:
diff changeset
    68
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
    69
489c9b5090e2 Initial load
duke
parents:
diff changeset
    70
inline HeapWord* ContiguousSpace::concurrent_iteration_safe_limit()
489c9b5090e2 Initial load
duke
parents:
diff changeset
    71
{
489c9b5090e2 Initial load
duke
parents:
diff changeset
    72
  assert(_concurrent_iteration_safe_limit <= top(),
489c9b5090e2 Initial load
duke
parents:
diff changeset
    73
         "_concurrent_iteration_safe_limit update missed");
489c9b5090e2 Initial load
duke
parents:
diff changeset
    74
  return _concurrent_iteration_safe_limit;
489c9b5090e2 Initial load
duke
parents:
diff changeset
    75
}
489c9b5090e2 Initial load
duke
parents:
diff changeset
    76
489c9b5090e2 Initial load
duke
parents:
diff changeset
    77
inline void ContiguousSpace::set_concurrent_iteration_safe_limit(HeapWord* new_limit)
489c9b5090e2 Initial load
duke
parents:
diff changeset
    78
{
489c9b5090e2 Initial load
duke
parents:
diff changeset
    79
  assert(new_limit <= top(), "uninitialized objects in the safe range");
489c9b5090e2 Initial load
duke
parents:
diff changeset
    80
  _concurrent_iteration_safe_limit = new_limit;
489c9b5090e2 Initial load
duke
parents:
diff changeset
    81
}
7397
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    82
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 5547
diff changeset
    83
#endif // SHARE_VM_MEMORY_SPACE_INLINE_HPP