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 #include "precompiled.hpp"
26 #include "gc_interface/collectedHeap.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/cardTableModRefBS.hpp"
29 #include "memory/cardTableRS.hpp"
30 #include "memory/space.inline.hpp"
31 #include "memory/universe.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "runtime/java.hpp"
34 #include "runtime/mutexLocker.hpp"
35 #include "runtime/orderAccess.inline.hpp"
36 #include "runtime/virtualspace.hpp"
37 #include "runtime/vmThread.hpp"
38
39 void CardTableModRefBS::non_clean_card_iterate_parallel_work(Space* sp, MemRegion mr,
40 OopsInGenClosure* cl,
41 CardTableRS* ct,
42 int n_threads) {
43 assert(n_threads > 0, "Error: expected n_threads > 0");
44 assert((n_threads == 1 && ParallelGCThreads == 0) ||
45 n_threads <= (int)ParallelGCThreads,
46 "# worker threads != # requested!");
47 assert(!Thread::current()->is_VM_thread() || (n_threads == 1), "There is only 1 VM thread");
48 assert(UseDynamicNumberOfGCThreads ||
49 !FLAG_IS_DEFAULT(ParallelGCThreads) ||
50 n_threads == (int)ParallelGCThreads,
51 "# worker threads != # requested!");
432 uintptr_t& lowest_non_clean_base_chunk_index,
433 size_t& lowest_non_clean_chunk_size) {
434
435 int i = find_covering_region_containing(sp->bottom());
436 MemRegion covered = _covered[i];
437 size_t n_chunks = chunks_to_cover(covered);
438
439 // Only the first thread to obtain the lock will resize the
440 // LNC array for the covered region. Any later expansion can't affect
441 // the used_at_save_marks region.
442 // (I observed a bug in which the first thread to execute this would
443 // resize, and then it would cause "expand_and_allocate" that would
444 // increase the number of chunks in the covered region. Then a second
445 // thread would come and execute this, see that the size didn't match,
446 // and free and allocate again. So the first thread would be using a
447 // freed "_lowest_non_clean" array.)
448
449 // Do a dirty read here. If we pass the conditional then take the rare
450 // event lock and do the read again in case some other thread had already
451 // succeeded and done the resize.
452 int cur_collection = Universe::heap()->total_collections();
453 if (_last_LNC_resizing_collection[i] != cur_collection) {
454 MutexLocker x(ParGCRareEvent_lock);
455 if (_last_LNC_resizing_collection[i] != cur_collection) {
456 if (_lowest_non_clean[i] == NULL ||
457 n_chunks != _lowest_non_clean_chunk_size[i]) {
458
459 // Should we delete the old?
460 if (_lowest_non_clean[i] != NULL) {
461 assert(n_chunks != _lowest_non_clean_chunk_size[i],
462 "logical consequence");
463 FREE_C_HEAP_ARRAY(CardPtr, _lowest_non_clean[i]);
464 _lowest_non_clean[i] = NULL;
465 }
466 // Now allocate a new one if necessary.
467 if (_lowest_non_clean[i] == NULL) {
468 _lowest_non_clean[i] = NEW_C_HEAP_ARRAY(CardPtr, n_chunks, mtGC);
469 _lowest_non_clean_chunk_size[i] = n_chunks;
470 _lowest_non_clean_base_chunk_index[i] = addr_to_chunk_index(covered.start());
471 for (int j = 0; j < (int)n_chunks; j++)
472 _lowest_non_clean[i][j] = NULL;
|
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 #include "precompiled.hpp"
26 #include "gc_interface/collectedHeap.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/cardTableModRefBS.hpp"
29 #include "memory/cardTableRS.hpp"
30 #include "memory/genCollectedHeap.hpp"
31 #include "memory/space.inline.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "runtime/java.hpp"
34 #include "runtime/mutexLocker.hpp"
35 #include "runtime/orderAccess.inline.hpp"
36 #include "runtime/virtualspace.hpp"
37 #include "runtime/vmThread.hpp"
38
39 void CardTableModRefBS::non_clean_card_iterate_parallel_work(Space* sp, MemRegion mr,
40 OopsInGenClosure* cl,
41 CardTableRS* ct,
42 int n_threads) {
43 assert(n_threads > 0, "Error: expected n_threads > 0");
44 assert((n_threads == 1 && ParallelGCThreads == 0) ||
45 n_threads <= (int)ParallelGCThreads,
46 "# worker threads != # requested!");
47 assert(!Thread::current()->is_VM_thread() || (n_threads == 1), "There is only 1 VM thread");
48 assert(UseDynamicNumberOfGCThreads ||
49 !FLAG_IS_DEFAULT(ParallelGCThreads) ||
50 n_threads == (int)ParallelGCThreads,
51 "# worker threads != # requested!");
432 uintptr_t& lowest_non_clean_base_chunk_index,
433 size_t& lowest_non_clean_chunk_size) {
434
435 int i = find_covering_region_containing(sp->bottom());
436 MemRegion covered = _covered[i];
437 size_t n_chunks = chunks_to_cover(covered);
438
439 // Only the first thread to obtain the lock will resize the
440 // LNC array for the covered region. Any later expansion can't affect
441 // the used_at_save_marks region.
442 // (I observed a bug in which the first thread to execute this would
443 // resize, and then it would cause "expand_and_allocate" that would
444 // increase the number of chunks in the covered region. Then a second
445 // thread would come and execute this, see that the size didn't match,
446 // and free and allocate again. So the first thread would be using a
447 // freed "_lowest_non_clean" array.)
448
449 // Do a dirty read here. If we pass the conditional then take the rare
450 // event lock and do the read again in case some other thread had already
451 // succeeded and done the resize.
452 int cur_collection = GenCollectedHeap::heap()->total_collections();
453 if (_last_LNC_resizing_collection[i] != cur_collection) {
454 MutexLocker x(ParGCRareEvent_lock);
455 if (_last_LNC_resizing_collection[i] != cur_collection) {
456 if (_lowest_non_clean[i] == NULL ||
457 n_chunks != _lowest_non_clean_chunk_size[i]) {
458
459 // Should we delete the old?
460 if (_lowest_non_clean[i] != NULL) {
461 assert(n_chunks != _lowest_non_clean_chunk_size[i],
462 "logical consequence");
463 FREE_C_HEAP_ARRAY(CardPtr, _lowest_non_clean[i]);
464 _lowest_non_clean[i] = NULL;
465 }
466 // Now allocate a new one if necessary.
467 if (_lowest_non_clean[i] == NULL) {
468 _lowest_non_clean[i] = NEW_C_HEAP_ARRAY(CardPtr, n_chunks, mtGC);
469 _lowest_non_clean_chunk_size[i] = n_chunks;
470 _lowest_non_clean_base_chunk_index[i] = addr_to_chunk_index(covered.start());
471 for (int j = 0; j < (int)n_chunks; j++)
472 _lowest_non_clean[i][j] = NULL;
|