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 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_MEMORY_CARDTABLEMODREFBS_HPP
26 #define SHARE_VM_MEMORY_CARDTABLEMODREFBS_HPP
27
28 #include "memory/modRefBarrierSet.hpp"
29 #include "oops/oop.hpp"
30
31 // This kind of "BarrierSet" allows a "CollectedHeap" to detect and
32 // enumerate ref fields that have been modified (since the last
33 // enumeration.)
34
35 // As it currently stands, this barrier is *imprecise*: when a ref field in
36 // an object "o" is modified, the card table entry for the card containing
37 // the head of "o" is dirtied, not necessarily the card containing the
38 // modified field itself. For object arrays, however, the barrier *is*
39 // precise; only the card containing the modified element is dirtied.
40 // Closures used to scan dirty cards should take these
41 // considerations into account.
42
43 class Generation;
44 class OopsInGenClosure;
45 class DirtyCardToOopClosure;
46 class ClearNoncleanCardWrapper;
47 class CardTableRS;
48
448 CardTableModRefBS(
449 whole_heap,
450 // Concrete tag should be BarrierSet::CardTableForRS.
451 // That will presently break things in a bunch of places though.
452 // The concrete tag is used as a dispatch key in many places, and
453 // CardTableForRS does not correctly dispatch in some of those
454 // uses. This will be addressed as part of a reorganization of the
455 // BarrierSet hierarchy.
456 BarrierSet::FakeRtti(BarrierSet::CardTableModRef, 0).add_tag(BarrierSet::CardTableForRS))
457 {}
458
459 void set_CTRS(CardTableRS* rs) { _rs = rs; }
460 };
461
462 template<>
463 struct BarrierSet::GetName<CardTableModRefBSForCTRS> {
464 static const BarrierSet::Name value = BarrierSet::CardTableForRS;
465 };
466
467
468 #endif // SHARE_VM_MEMORY_CARDTABLEMODREFBS_HPP
|
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 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_GC_SHARED_CARDTABLEMODREFBS_HPP
26 #define SHARE_VM_GC_SHARED_CARDTABLEMODREFBS_HPP
27
28 #include "gc/shared/modRefBarrierSet.hpp"
29 #include "oops/oop.hpp"
30
31 // This kind of "BarrierSet" allows a "CollectedHeap" to detect and
32 // enumerate ref fields that have been modified (since the last
33 // enumeration.)
34
35 // As it currently stands, this barrier is *imprecise*: when a ref field in
36 // an object "o" is modified, the card table entry for the card containing
37 // the head of "o" is dirtied, not necessarily the card containing the
38 // modified field itself. For object arrays, however, the barrier *is*
39 // precise; only the card containing the modified element is dirtied.
40 // Closures used to scan dirty cards should take these
41 // considerations into account.
42
43 class Generation;
44 class OopsInGenClosure;
45 class DirtyCardToOopClosure;
46 class ClearNoncleanCardWrapper;
47 class CardTableRS;
48
448 CardTableModRefBS(
449 whole_heap,
450 // Concrete tag should be BarrierSet::CardTableForRS.
451 // That will presently break things in a bunch of places though.
452 // The concrete tag is used as a dispatch key in many places, and
453 // CardTableForRS does not correctly dispatch in some of those
454 // uses. This will be addressed as part of a reorganization of the
455 // BarrierSet hierarchy.
456 BarrierSet::FakeRtti(BarrierSet::CardTableModRef, 0).add_tag(BarrierSet::CardTableForRS))
457 {}
458
459 void set_CTRS(CardTableRS* rs) { _rs = rs; }
460 };
461
462 template<>
463 struct BarrierSet::GetName<CardTableModRefBSForCTRS> {
464 static const BarrierSet::Name value = BarrierSet::CardTableForRS;
465 };
466
467
468 #endif // SHARE_VM_GC_SHARED_CARDTABLEMODREFBS_HPP
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