Mercurial > hg > graal-jvmci-8
annotate src/share/vm/memory/space.inline.hpp @ 3917:eca1193ca245
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
author | ysr |
---|---|
date | Wed, 07 Sep 2011 13:55:42 -0700 |
parents | f95d63e2154a |
children | a05a695ea044 |
rev | line source |
---|---|
0 | 1 /* |
1972 | 2 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
342
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
342
diff
changeset
|
20 * or visit www.oracle.com if you need additional information or have any |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
342
diff
changeset
|
21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #ifndef SHARE_VM_MEMORY_SPACE_INLINE_HPP |
26 #define SHARE_VM_MEMORY_SPACE_INLINE_HPP | |
27 | |
28 #include "gc_interface/collectedHeap.hpp" | |
29 #include "memory/space.hpp" | |
30 #include "memory/universe.hpp" | |
31 #include "runtime/safepoint.hpp" | |
32 | |
342 | 33 inline HeapWord* Space::block_start(const void* p) { |
34 return block_start_const(p); | |
35 } | |
36 | |
0 | 37 inline HeapWord* OffsetTableContigSpace::allocate(size_t size) { |
38 HeapWord* res = ContiguousSpace::allocate(size); | |
39 if (res != NULL) { | |
40 _offsets.alloc_block(res, size); | |
41 } | |
42 return res; | |
43 } | |
44 | |
45 // Because of the requirement of keeping "_offsets" up to date with the | |
46 // allocations, we sequentialize these with a lock. Therefore, best if | |
47 // this is used for larger LAB allocations only. | |
48 inline HeapWord* OffsetTableContigSpace::par_allocate(size_t size) { | |
49 MutexLocker x(&_par_alloc_lock); | |
50 // This ought to be just "allocate", because of the lock above, but that | |
51 // ContiguousSpace::allocate asserts that either the allocating thread | |
52 // holds the heap lock or it is the VM thread and we're at a safepoint. | |
53 // The best I (dld) could figure was to put a field in ContiguousSpace | |
54 // meaning "locking at safepoint taken care of", and set/reset that | |
55 // here. But this will do for now, especially in light of the comment | |
56 // above. Perhaps in the future some lock-free manner of keeping the | |
57 // coordination. | |
58 HeapWord* res = ContiguousSpace::par_allocate(size); | |
59 if (res != NULL) { | |
60 _offsets.alloc_block(res, size); | |
61 } | |
62 return res; | |
63 } | |
64 | |
342 | 65 inline HeapWord* |
66 OffsetTableContigSpace::block_start_const(const void* p) const { | |
0 | 67 return _offsets.block_start(p); |
68 } | |
69 | |
70 inline HeapWord* ContiguousSpace::concurrent_iteration_safe_limit() | |
71 { | |
72 assert(_concurrent_iteration_safe_limit <= top(), | |
73 "_concurrent_iteration_safe_limit update missed"); | |
74 return _concurrent_iteration_safe_limit; | |
75 } | |
76 | |
77 inline void ContiguousSpace::set_concurrent_iteration_safe_limit(HeapWord* new_limit) | |
78 { | |
79 assert(new_limit <= top(), "uninitialized objects in the safe range"); | |
80 _concurrent_iteration_safe_limit = new_limit; | |
81 } | |
1972 | 82 |
83 #endif // SHARE_VM_MEMORY_SPACE_INLINE_HPP |