1 /*

     2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

     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  *

    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/g1/g1CollectedHeap.hpp"

    27 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"

    28 #include "gc/g1/g1FullCollector.hpp"

    29 #include "gc/g1/g1FullGCCompactionPoint.hpp"

    30 #include "gc/g1/g1FullGCCompactTask.hpp"

    31 #include "gc/g1/heapRegion.inline.hpp"

    32 #include "gc/shared/gcTraceTime.inline.hpp"

    33 #include "logging/log.hpp"

    34 #include "utilities/ticks.inline.hpp"

    35 

    36 class G1ResetHumongousClosure : public HeapRegionClosure {

    37   G1CMBitMap* _bitmap;

    38 

    39 public:

    40   G1ResetHumongousClosure(G1CMBitMap* bitmap) :

    41       _bitmap(bitmap) { }

    42 

    43   bool doHeapRegion(HeapRegion* current) {

    44     if (current->is_humongous()) {

    45       if (current->is_starts_humongous()) {

    46         oop obj = oop(current->bottom());

    47         if (_bitmap->is_marked(obj)) {

    48           // Clear bitmap and fix mark word.

    49           _bitmap->clear(obj);

    50           obj->init_mark();

    51         } else {

    52           assert(current->is_empty(), "Should have been cleared in phase 2.");

    53         }

    54       }

    55       current->reset_during_compaction();

    56     }

    57     return false;

    58   }

    59 };

    60 

    61 size_t G1FullGCCompactTask::G1CompactRegionClosure::apply(oop obj) {

    62   size_t size = obj->size();

    63   HeapWord* destination = (HeapWord*)obj->forwardee();

    64   if (destination == NULL) {

    65     // Object not moving

    66     return size;

    67   }

    68 

    69   // copy object and reinit its mark

    70   HeapWord* obj_addr = (HeapWord*) obj;

    71   assert(obj_addr != destination, "everything in this pass should be moving");

    72   Copy::aligned_conjoint_words(obj_addr, destination, size);

    73   oop(destination)->init_mark();

    74   assert(oop(destination)->klass() != NULL, "should have a class");

    75 

    76   return size;

    77 }

    78 

    79 void G1FullGCCompactTask::compact_region(HeapRegion* hr) {

    80   assert(!hr->is_humongous(), "Should be no humongous regions in compaction queue");

    81   G1CompactRegionClosure compact(collector()->mark_bitmap());

    82   hr->apply_to_marked_objects(collector()->mark_bitmap(), &compact);

    83   // Once all objects have been moved the liveness information

    84   // needs be cleared.

    85   collector()->mark_bitmap()->clear_region(hr);

    86   hr->complete_compaction();

    87 }

    88 

    89 void G1FullGCCompactTask::work(uint worker_id) {

    90   Ticks start = Ticks::now();

    91   GrowableArray<HeapRegion*>* compaction_queue = collector()->compaction_point(worker_id)->regions();

    92   for (GrowableArrayIterator<HeapRegion*> it = compaction_queue->begin();

    93        it != compaction_queue->end();

    94        ++it) {

    95     compact_region(*it);

    96   }

    97 

    98   G1ResetHumongousClosure hc(collector()->mark_bitmap());

    99   G1CollectedHeap::heap()->heap_region_par_iterate_from_worker_offset(&hc, &_claimer, worker_id);

   100   log_task("Compaction task", worker_id, start);

   101 }

   102 

   103 void G1FullGCCompactTask::serial_compaction() {

   104   GCTraceTime(Debug, gc, phases) tm("Phase 4: Serial Compaction", collector()->scope()->timer());

   105   GrowableArray<HeapRegion*>* compaction_queue = collector()->serial_compaction_point()->regions();

   106   for (GrowableArrayIterator<HeapRegion*> it = compaction_queue->begin();

   107        it != compaction_queue->end();

   108        ++it) {

   109     compact_region(*it);

   110   }

   111 }